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Symbiotic Associations; Mycorrhial Fungi and Mycorrhizae
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Source: http://www.noble.org/MedicagoHandbook/pdf/ArbuscularMycorrhiza.pdf, http://botit.botany.wisc.edu/courses/mpp/AM.html
Enhancement: Below is a picture of Colonization of a flax root by Arbuscular Mycorrhizal Fungi. The black areas within the root are locations of transfer of phosphorus from the fungus to flax called Arbuscules. In exchange, the fungus obtain food energy from the flax. The thin black strands joining the Arbuscules are also the fungus and these extend into soil increasing the root system of the flax plant.
http://images.google.ca/imgres?imgurl=http://www.umanitoba.ca/afs/graphics/fiw_tenuta_fig2.jpg&imgrefurl=http://www.umanitoba.ca/afs/fiw/060105.html&h=345&w=463&sz=49&hl=en&start=2&um=1&tbnid=EON1k6tSEjPdEM:&tbnh=95&tbnw=128&prev=/images%3Fq%3DArbuscular%2BMycorrhizal%2Bfungi%26svnum%3D10%26um%3D1%26hl%3Den -Nick N
Arbuscule An arbuscule is hypha that penetrates a root cornical cell, forming a tree-like structure. ( Mycorrhizas: Anatomy and Biology, Peterson, L., et.al. pg. 163) The arbuscule does not enter the protoplast, it surrounds the protoplast, and causes infolding and increasing of the protoplasts area. This increases the transfer of nutrients between the cell that the fungi. The hypha also extends out of the cell into the soil, increasing the absorption of water and nutrients of the cell. (Raven, pg. 292-293) Arbuscules are endomycorrhizae, made up of around 200 species of zygomycota fungi, and inhabit root cells of around 80 percent of vascular plants. This type of mycorrhizal fungi is totally dependent on plants as host cells (obligate biotrophs).(Mycorrhizas: Anatomy and Biology, Peterson, L., et.al. pg. 163) Jake
Enhancement:
Note the distinct tree like shape
http://biology.kenyon.edu/fennessy/SrexMarx/arbgood.jpg
--John
Ascomycete (Caitlin Deas)
The ascomycetes are one of two major groups in the septate fungi (the other is the basidiomycetes). They are septate since their hyphae have cross-walls, or septae. They usually produce a fruiting body (a mushroom-like growth), which produces the spores sexually. The spores (called ascospores) are produced inside little sac-shaped enclosures called asci in a layer in this fruiting body. (Nature Navigator) http://internt.nhm.ac.uk/jobj/runjava.jobj?java=ctol.CTOLServer&method=printNamePage&accountref=987&NAMEID=27084
They also reproduce asexually by forming nonsexual spores (conidia) at the ends of their hyphae. Some examples of ascomycetes are yeasts, morels, truffles, Dutch elm disease and ergot. (The Free Dictionary by Farlex) http://www.thefreedictionary.com/ascomycete
There are 15,000 species in 1,950 genera of ascomycetes. The lichens form the largest group. (The Free Dictionary by Farlex)http://encyclopedia.farlex.com/ascomycete
This is a picture of orange-peel fungus, Aleuria aurantia,a non-lichenised ascomycete fungus.
(Fathom)
http://www.fathom.com/feature/122560/3051_lichen9_SM.jpg
Ascospore: Type of sexual spore produced within the ascus; found in ascomycetes. 4-8 spores are produced in the Ascomycetes and are capable of asexual reproduction Biology of plants 7th edition http://www.britannica.com -Travis Unsworth
Enhancement(Andrea Chapman) Ascospores through an Electron Micrograph (AFTOL Project - http://www.clarku.edu/faculty/dhibbett/TFTOL/images/ascospore.jpg)
Enhancment(Jackie Taylor) - They are haploid cells formed after meiosis. Ascospores are unique structures that distinguish the ascomycetes from all other fungi. They are recognizable by the fact that they have no attachment points, and are sometimes enclosed in gelatinous sheaths or within a sac. Produced by morels, truffles, cup fungi, ergot and many micro-fungi. Biology of Plants, 7th edition, Peter H. Raven, Glossary pg. 271-272 EM Lab P&K - https://www.emlab.com/app/fungi/Fungi.po?event=fungi&species=4&type=secondary
Ascus (Caitlin Deas)
The ascus is a sac-shaped enclosure in the fruiting body of an ascomycete. It contains the sexual ascospores, which are formed by an enveloping membrane system. In this system, mitosis follows meiosis to form eight nuclei, which become eight ascospores eventually. Below is a picture of Taphrina, the asci of the peach leaf curl fungus atop a peach leaf.
(Tree of Life Web Project)
http://www.tolweb.org/Ascomycota
Although the ascus usually generates only eight ascospores, there are some that produce many more (even thousands). (Illinois Mycological Association) http://www.ilmyco.gen.chicago.il.us/Terms/ascus134.html
Enhancement: The ascus is a saclike structure produced by fungi of the class Ascomycetes (sac fungi) in which sexually produced spores (ascospores), usually four or eight in number, are formed. Asci may arise from the fungal mycelium (the filaments, or hyphae, constituting the organism) without a distinct fruiting structure, as in the leaf curl fungi; it may arise within a fruiting structure (ascocarp) that may be exposed, as in the molds and powdery mildew fungi; or it may be imbedded in a compact structure (stroma), as in the ergot and black knot fungi. In the case of yeasts, a single cell converts to an ascus. (Encyclopedia Britannica Online, http://www.britannica.com/eb/article-9000538/ascus ). Lee Williams.
Basidiospore:
Spores produced by fungi in the family Basidiomycota (Raven, 7th ed.). Basidiospores are produced by reproductive cells called basidia through meiosis and nuclear fisson. They are uninucleate and haploid. When basidiospores are discharged they germinate to form the primary mycelia of a new fungus. (Introductory Mycology. Alexopoulos, C.J. and Mims, C.W., 1979) (Raven, 7th ed.)
Katherine Loewen
The arrow points to an example of a basidiospore. www.botany.hawaii.edu (Matti Harper)
Basidiospore (Enhancement) - When basidiospores encounter a favorable substrate, they may germinate, typically by forming hyphae. These hyphae grow outward from the original spore, forming an expanding circle of mycelium. Some basidiospores germinate repetitively by forming small spores instead of hyphae. (Tree of Life: Basidiomycota). Atypical mushroom produces billions of basidiospores. (The American Heritage Science Dictionary).
- Mark Dinicol
Basidium:
Club-shaped reproductive cell of the fungal family basidiomycota. Each basidium produces 4 basidiospores through meiosis and nuclear fisson. The basidiospores are borne on stalk-like structures called stigmata. (Raven, 7th ed.) (Introductory Mycology. Alexopoulos, C.J. and Mims, C.W., 1979)
Katherine Loewen
Basidium (Enhancemen)t: A reproductive appendage that produces sexual spores on the gills of mushrooms. (Biology 7th Edition, Campbell and Reece, pg. 618) Lacey Loewen
Basidium (Enhancement) - a microscopic, spore-producing structure found on the hymenophore of fruiting bodies of basidiomycete fungi. The basidium is unique to basidiomycetes and distinguishes them from other kinds of fungi. (The American Heritage® Science Dictionary)
Most basidiomycetes have single celled basidia, but in some groups basidia can be multicellular. (Ingold, 1998. Ballistosporic basidia).
Scanning electron micrograph of basidia on the gills of a toadstool. Note that each basidium produces four stalks (sterigmata) and the basidiospores develop on the ends of these stalks. (The Microbial World: Basidiomycota)
-Mark Dinicol
Commensalism -term used to describe a relationship between two living organisms where one benefits and the other is not significantly harmed or helped. (H.T. Baumgarten & K. Fiedler 1998. Parasitoids of lycaenid butterfly caterpillars). Some biologists argue that any close interaction between two organisms is unlikely to be completely neutral for either party, and that relationships identified as commensal are likely mutualistic or parasitic in a subtle way that has not been detected. (Benzing, D.H. 1980. Biology of the Bromeliads.)
The relationship of barnacles on gray whales is an example of commensalism
-Mark Dinicol
Enhancement = commensalism RSwite
A mutualistic relationship where one individual benefits while the other is neither harmed nor benefited. For example, the dung beetle relies on the scat of the gopher tortoise which it crafts into a ball and rolls to a location where it can be eaten later. ...
www.auburn.edu/academic/forestry_wildlife/longleafalliance/teachers/teacherkit/glossary.htm A mutualistic relationship where one individual benefits while the other is neither harmed nor benefited. For example, the dung beetle relies on the scat of the gopher tortoise which it crafts into a ball and rolls to a location where it can be eaten later. ...
www.auburn.edu/academic/forestry_wildlife/longleafalliance/teachers/teacherkit/glossary.htm Commensialism means literally 'at table together'. This is a symbiotic relationship between two species in which one species benefits and the other neither benefits or harms. Often, the host species provides a home and/or transportation for the other species. http://www.botany.uwc.ac.za/sci_ed/grade10/ecology/symbiosis/commen.htm
Endomycorrhiza: The mass of hyphae forming the body of a fungus, oomycete, or chytrid. Endomycorrhizae does not form a fungal sheath around the root like ectomycorrhizae does, but it penetrates the cortical cells but doesn’t penetrate the cell membrane- Travis Unsworth http://www.uwlax.edu/biology Biology of Plants 7th Edition
Endomycorrhizae are in soil fungi's which pernetrate plant root cells and increases both the plants and fungi's uptake of nutrients. This plant/fungi relationship is known as the mycorrhiza fungi. (Jackie Taylor)
http://www.nrp48.ch/projects/projects_detail.php?nfprojnum=17&isactdescr=yes Biology of Plants, 7th edition, Peter H. Raven, Glossary pg. 266.
Hartig net - a complex network of fungal hyphae that is the site of nutrient exchange between the fungus and the host plant. (McGraw-Hill Dictionary of Scientific and Technical Terms 2003). It is formed in ectomycorrhizae by hyphae which grow between the cells of the root epidermis and cortex. The Hartig net eventually surrounds many of the cortical and epidermal cells. In the roots of most angiosperms colonized by ectomycorrhizal fungi, the epidermal cells are triggered to enlarge primarily at right angles to the surface of the root, thickening the root rather than extending it, and the Hartig net is confined to this layer. (Raven. Biology of Plants 2005.)
Diagram of typical ectomycorrhiza including the Hartig net, fungal mantle and external hyphae
- Mark Dinicol
Hyphae - long slender tubes that develop from germinated spores and form the structural parts of the body of a fungus. (Martinko J. 2005. Brock Biology of Microorganisms). In many species of fungi, hyphae are divided into sections by cross walls called septa. Each section contains at least one haploid nucleus, and the septa usually have perforations that allow cytoplasm to flow through the hypha. A large mass of hyphae is known as a mycelium, which is the growing form of most fungi. (The American Heritage Science Dictionary. 2005).
Hyphae of Penicillium
- Mark Dinicol
Enhancement (Hyphae): The vast majority of fungi are filamentous and the vegetative stage is a cylindrical thread-like filament called a hypha. Most hyphae are 2-10 um across, and cannot be resolved by the naked eye. The hyphal wall is quite tough, and composed of mainly of chitin (www.uoguelph.ca/~gbarron/MISCELLANEOUS/hyphae.htm). Hyphae contain nuclei, mithochondria, robosomes, Golgi and membrane-bound vesicles within a plasma-membrane bound cytoplasm (MicrobiologyBytes 2007, online). Tessa J Enhancement – Jessi.E.W There are three different types of hyphae which include generative hypha, skeletal hypha and binding hypha. If all three are present in the fungi then the fungi is termed polypore hyphae.
Host (AarenS)
A host is an organism that is being predated upon by a parasite, which is an organism that is dependant upon the host to live, grow, and multiply. A host in such a relationship does not benefit from the relationship, but is instead harmed by the parasite in various ways and can even be killed by the relationship it has with the parasite. Examples could be a tree or shrub acting as host to a mistletoe (parasitic plant from the order santalales seen below) which does not end until the death of either the host or the parasite, a human being bit by a mosquito which is a form of parasitism that does not last very long, or a vertibrate carrying a tape worm.
(Biology of Plants, 7th edition)
(http://www.science.siu.edu/parasitic-plants/)
Enhancement (Stephanie Lauer): a host is the larger participant in a symbiotic relationship, serving as a home and feeding ground to the symbiont (the smaller participant in the symbiotic relationship). Symbiotic relationships are classified as either mutualism, commensalism or parasitism. In mutualism both of the organims are benefit, in commensalism one organism benefits while the neither helping nor harming the other in any significant way and a parasitism mean one organism benefits at the cost of the other (Campbell & Reece, Biology 7th ed. pg 545)
Intracellular growth = RSwite Plant cells engage in mutualistic and parasitic endosymbioses with a wide variety of microoganisms, ranging from Gram-negative (Rhizobium, Nostoc) and Gram-positive bacteria (Frankia), to oomycetes (Phytophthora), Chytridiomycetes, Zygomycetes (arbuscular mycorrhizal fungi) and true fungi (Erysiphe, ascomycete; Puccinia, basidiomycete). Endosymbiosis is characterised by the 'symbiosome', a compartment within host cells in which the symbiotic microorganism is either partially or completely enclosed by a host-derived membrane. The analysis of plant mutants indicates that the genetic requirements for the interaction with rhizobia and arbuscular mycorrhiza fungi are partially overlapping. The extent to which plants use similar or identical developmental programs for the intracellular accommodation of different microorganisms is, however, not clear. For example, plant cells actively weaken their cell wall to facilitate bacterial colonisation, whereas penetration by fungal symbionts appears not to be assisted in this manner. Moreover, different transport requirements are imposed on the symbiotic interface of different interactions indicating that additional system-specific components are likely to exist. http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6VS4-40NMR23-C&_user=10&_coverDate=08%2F01%2F2000&_rdoc=1&_fmt=&_orig=search&_sort=d&view=c&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=e5a654926bf1378c54faebda2d237828
Figure 1 Here is a piture showing how cells interact with one another when it
comes to intracellular growth and nutrient sharing. www.emc.maricopa.edu/.../BIOBK/waterflow.gif
RSwite
Mantle The mantle, or fungal mantle, is a sheath or net-like mesh of fungal hyphae that forms around roots. This sheath like fungus is generally ectomychorizae, and is comprised of mainly bacidiomycetes fungi, and less often ascomycetes fungi. Certain hormones are secreted by the fungi of the mantle that may cause the root to branch. (Raven, pg. 292-293) The hyphae of the inner mantle make up the hartig net, which is a complex nutrient transfer system between both cortex and epidermal cells. The fungal mantle increases the absorption of water and nutrients of the root system, benefiting the plant.( Mycorrhizas: Anatomy and Biology, Peterson, L., et.al. pg. 22,163) Jake
Enhancement (Nicole L) This is a picture of fungal mantle surrounding roots of a plant host
Image from ocid.nacse.org/.../bot461/imghtm/ectotips.htm
Mutualism The relation between two different species of organisms that are interdependent; each gains benefits from the other. A type of symbiosis where two (or more) organisms from different species live in close proximity to one another and rely on one another for nutrients, protectio, or other lif funcitons. Both (or all) of the organisms invloved benefit from the relationship. http://www.biology-online.org/dictionary/Mutualism a relationship between two organisms of different species that benefits both and harms neither. For example, lichens are a fungus and an alga living in mutualism: The fungus provides a protective structure, and the alga produces a carbohydrate as food for the fungus. http://encarta.msn.com/dictionary_/mutualistic.html R.Swite
Enhancement: Amanda Last Mutualism: association between organisms of two different species in which each is benefited. Mutualistic arrangements are most likely to develop between organisms with widely differing living requirements. The partnership between nitrogen-fixing bacteria and leguminous plants is an example, as is the association between cows and rumen bacteria (the bacteria live in the digestive tract and help digest the plants eaten by the cow). The associations between tree roots and certain fungi are often mutualistic.(Britannica Online Encyclopedia). The relationship existing between two organisms of different species which contribute mutually to each other's well-being; an instance of this.(Oxford English Dictionary).
Enhacement:
As seen in the picture, mycorrizal fungi benefits the plant by increasing its absorbance surface area.It is benafitted by food it obtains from the plant.Both cannot live properly without each other.
(Plant Health Care.co.uk,http://www.planthealth care.co.uk/images/fungi.gif)
(Raven, Biology of plants, pg. 291)
Jake
Mycelium: Mass of hyphae that constitutes the vegetative part of a fungus. The mycelium makes up the thallus, or undifferentiated body, of a typical fungus. It may be microscopic in size or developed into visible structures, such as brackets, mushrooms, puffballs, rhizomorphs http://cancerweb.ncl.ac.uk/cgi-bin/omd?mycelium http://www.britannica.com Travis Unsworth
Enhancement (Andrea Chapman) Armillaria root rot (Armillaria ostoyae) is a common fungus found in British Columbia’s forests that is easily identifiable by its mycelial fans. These fans are a white/creamy colour and found under the bark at the base of the stump and roots (Cruickshank et al. 1997).
Cruickshank M.G., Morrison D.J., and Punja Z. K. 1997. Incidence of Armillaria species in precommercial thinning stumps and spread of Armillaria ostoyae to adjacent Douglas-fir trees. Canadian Journal of Forest Research 27: 481-490
Enhancement (Nick N) This is a picture of mycelium growing on a decomposed log.www.ipm.iastate.edu/.../2006/4-5/fungi.html
Parasite: A parasite is something that lives in dependence of another organism in order to maintain its existence. These organisms do not give back to the host that they feed from. Instead they usually cause harm, but rarely do they kill the host. The parasite has to be in its host to live, grow and multiply. A common, well-known type of a parasite is a hookworm. Hookworms can be commonly found in mammals, most commonly humans and domestic animals. Hookworms attach themselves in the lining of the small intestine, and cause diseases, and malnutrition as well, as they eat the nutrients and keep them from going to the host.
Fig.1: a common parasite, the hookworm. Found in the small
intestine of humans and their domestic animals.
References: http://student.biology.arizona.edu/honors98/group15/whatisaparasite.htm
http://www.m-w.com/dictionary/parasite
http://phil.cdc.gov/phil/home.asp
Public Health Image Library] Image #5205
-Scott Horley
Parasite (enhancement) - Parasites that live inside the live body of the host are called endoparasites (e.g., hookworms that live in the host's gut), and those that live on the outside are called ectoparasites (e.g., some mites). (Zimmer, Carl 2001. Parasite Rex) .Many endoparasites acquire hosts by gaining entrance to their tissue; others enter the host when it consumes certain raw foods. Ectoparasites, on the other hand, often have elaborate mechanisms and strategies for finding hosts. Some aquatic leeches, for example, locate hosts by sensing movement and then confirm their identity through skin temperature and chemical cues before attaching. (The American Heritage® Science Dictionary)
Mites parasitising a harvestman
- Mark Dinicol
Pathogen
Pathogen: An agent of disease. A disease producer. The term pathogen most commonly is used to refer to infectious organisms. These include bacteria, viruses , and fungi. Less commonly, pathogen refers to a noninfectious agent of disease such as a chemical. http://dendroglossary.wetpaint.com/page/Symbiotic+Associations%3B+Mycorrhial+Fungi+and+Mycorrhizae A disease producing organisms that can exist in many different places. (for example: air, dust, counter top surface, the body, etc.) A pathogen or infectious agent is a biological agent that causes diseaseor illness to its host. The term is most often used for agents that disrupt the normal phisiology of a multicellular animal or plant. however, pathogens can infect unicellular organisms from all of the biological kingdoms. http://www.biology-online.org/dictionary/Pathogens R.Swite
www.scielo.br/img/fbpe/fb/v27n4/a17fig01.gif
A picture showing the effects that some pathogen have on trees.R.Swite Enhancement: Pathogens are identified by the hosts they infect and the symptoms they cause; it is also important to identify the specific properties of the pathogen that contribute to its infectious capacity—a characteristic known as virulence. http://www.britannica.com/eb/article-216178/microbiology Travis Unsworth
Rhizoshere:
The Rhizosphere is the area that surrounds the roots of plants. The Rhizosphere is directly influenced by the root’s secretions, the soil microorganisms and the soil itself. The root of the plant and the biofilm of the root can greatly influence the soil. The Rhizosphere can change the soils pH and nitrogen transformations by crowding the bacteria from the sloughed-off plant cells as well as the proteins and sugars the root releases.
Ref:
http://www.regional.org.au/au/allelopathy/2005/2/3/2535_fujiiy.htm?print=1
http://uwstudentweb.uwyo.edu/T/Twhite/
-Scott Horley Enhancement = rhizosphere RSwite The soil zone that surrounds and is influenced by the roots of plants. Within the rhizosphere, roots secrete a slimy lubricating substance, called mucigel, that cause the particles of soil to adhere to the roots, assisting in the uptake of water, and encourages the growth of nitrogen-fixing bacteria and other beneficial microorganisms. http://www.thefreedictionary.com/rhizosphere...The area immediately surrounding plant roots that is responsible for creating the conditions of this micro-habitat when taking into account the properties and actions of the plant. http://www.biology-online.org/dictionary/Rhizosphere RSWITE
Saprophyte: An organism, that obtains food by breaking down organic matter into simple compounds and absorbs nutrients from those compounds. Saprophytes include mainly fungi and bacteria, but also include molds, actinomycetes, and a select few plants and animals. (Ryan T)
http://www.bookrags.com/research/saprophyte-enve-02/ (para1
http://dictionary.reference.com/browse/Saprophyte (def #'s 2 & 5)
Enhancement –Saprophyte decomposing dead wood. fungifest.com Jessi.E.W
Enhancement = Saprophyte RSwite Any plant growing on decayed animal or vegetable matter, as most fungi and some flowering plants with no green color, as the Indian pipe. http://dict.die.net/saprophyte/ An organism, especially a fungus or bacterium, that grows on and derives its nourishment from dead or decaying organic matter. http://www.answers.com/topic/saprophyte?cat=health
Symbiosis Meaning derived from the Greek word symbiosis meaning “a living together”. (Online Etymology Dictionary, http://dictionary.reference.com/browse/Symbiosis) This term is used to describe a close association, or bond between two or more organisms of different species, often but not always benefiting each partner. An example of a symbiotic relationship is of Lichen (fungi) and Bacteria. (The American Heritage® Science Dictionary.) http://dictionary.reference.com/browse/Symbiosis) There are four types of symbiotic relationships, Mutualism, (which is a mutually beneficial relationship where each is dependent on other organism), Commensalism , (not a dependent relationship, but is mutually beneficial), Paratism, (where a parasite is dependent on its host, but harms it in the process), and amensalism,(much like parasitism: a relationship where one organism is benefited and the other is inhibited or harmed). (The American Heritage® Science Dictionary, http://dictionary.reference.com/browse/Symbiosis)( Online Etymology Dictionary, http://dictionary.reference.com/browse/Symbiosis) Jake
Enhancement: By Conyr A.
This photo shows a symbiotic relationship between a young tree and a fully developed tree. In this case it would be considered an amensalism relationship because only the smaller tree benefits from growing off the developed one. (Image from: istockphoto.com at the address http://www1.istockphoto.com/file_thumbview_approve/190375/2/istockphoto_190375_symbiosis.jpg)
Zygomycete (Caitlin Deas)
A fungus, such as bread mold, that lives on organic matter or as a parasite, in the ClassZygomycetes. (Encarta)
http://encarta.msn.com/dictionary_561563378/zygomycete.html Zygomycetes have hyphae that are continuous tubes, without cross-walls. They are one of two major groups of the aseptate fungi (the other group is the chytrids).
(Nature Navigator)
http://internt.nhm.ac.uk/jobj/runjava.jobj?java=ctol.CTOLServer&method=printNamePage&accountref=987&NAMEID=27087
Below are two examples of zygomycetes. The first is Pilaira anomala on deer feces. The second is Phycomyces blakesleeanus
(Cornell Mushroom Blog)
http://hosts.cce.cornell.edu/mushroom_blog/index.php?paged=3
(JGI)
http://genome.jgi-psf.org/Phybl1/Phybl1.home.html
Enhancement: Terrestrial saprobes or parasites of plants, animals, or humans; asexual reproduction by aplanospores (nonmotile spores) in sporangia or by conidia; sexual reproduction by fusion of morphologically similar gametangia, sometimes differing in size, resulting in thick-walled zygospores. (Encyclopedia Britannica Online, http://www.britannica.com/eb/article-57977/fungus ). Lee Williams.
Compare and Contrast (first word alphabetical)
Arbuscule/Mantle An arbuscule is a hypha that penetrates a roots cornical cell, and froms a tree- like web around the cortex. The Fungal mantle surrounds s the outside of the tree root in a sheath like mass of fungal hyphae. Both fungi help in the absorption of water and nutrients and transfer them to the trees roots. Both structures “surround” organ and transfer substances. They differ in that the arbuscule penetrates a cell, and the mantle surrounds the outside. An arbuscule is endomycorrhizea, formed of around 200 species of zygomycotic fungi and live in 80% of vascular plant roots; whereas, the mantle, which is ectomycorrhizea, is generally made of bacidiomycetes or ascomycetes fungi, and are generally found on the roots of certain groups of trees and shrubs, and are generally quite species specific. There are around 5000 species of fungi in ectomycorrhizal associations. (Raven, pg. 292-293) An arbuscule, or endomycorrizal fungi is dependent on a host cell and cannot by cultured on its own, whereas the mantle fungi can be cultured on its own. (Mycorrhizas: Anatomy and Biology, Peterson, L., et.al. pg. 163) Jake
Ascus/Ascospore (Dennis Murengi) Ascus: A specialised cell, characteristic of the ascomycetes, in which two of the haploid nuclei fuse to produce a zygote that immediately divides by meiosis; at maturity, an ascus contains ascospores. (Biology of Plants 7th Edition G-3) Ascospore: A spore produced within an ascus; found in ascomycetes. (Biology of Plants 7th Edition G-3) Both the ascus and ascospore are found in a type of fungi called ascomycetes. (Biology of Plants 7th Edition, Pg 271) However ascus and ascospore differ in their structure. The ascus has a saclike structure while the ascospores are spores formed inside the ascus. (Biology of Plants 7th Edition, Pg 271)
The image above shows an ascus which contains ascospores. (www.tolweb.org) http://www.tolweb.org/Ascomycota
Ascomycete/ Ascospore: Ascomycete: any of a subdivision (Ascomycotina) of fungi, including the mildews, yeasts, and truffles, that produce spores in asci; sac fungus. www.yourdictionary.com/ascomycete Ascospore:
Ascomycetes and Basidiomycetes - species belonging to the two large phyla Basidiomycota and Ascomycota, which together comprise the subkingdom Dikarya, also refered to as the "Higher Fungi" within the Kingdom Fungi. (Moore, R.T. (1980). "Taxonomic proposals for the classification of...). Basidiomycota include mushrooms, puffballs, stinkhorns, bracket fungi, other polypores, jelly fungi etc. They are filamentous fungi composed of hyphae and reproduce sexually via speicalized end cells, however some can reproduce asexually. Ascomycota are commonly known as the "Sac Fungi", with some familiar examples being morels, truffles, Baker's yeast, cup fungi, and the majority of lichens. When reproducing sexually, they produce nonmotile spores in a distinct cell called an "ascus". However, some do not reproduce sexually. (John W. 1996. "Ascomycota", Tree of Life).
Ascomycete / zygomycete: Ascomycete are fungus in the phylum Ascomycota characterized by the presence of sexually produced spores formed within an ascus. The nature of hyphae is Septate, their method of asexual reproduction is by budding, conidia(nonmotile spores) and fragmentation and their type of sexual spore is an ascospore.Some common plant diseases cause by ascomycete are powdery mildew, brown rot of stone fruits, chestnut blight and Dutch elm disease. Zygomycete are fungus from the Zygomycota phylum. The nature of hyphae is aseptate and coenocytic, method of asexual reproduction is nonmotile spores(sporangiospores), the type of sexual spore is a zygospore(in zygosporangium), and they cause soft rot of various plant parts. (http://www.thefreedictionary.com/ascomycete) (Biology of Plants P. 263)
-VanessaV
Ascospore/Basidiospore (Jessica Wrench)
Ascospore- “A spore produced within the ascus; found in ascomycetes.” (Biology of Plants 7th ed. Peter H. Raven, Pg. G-3)
Basidiospore- “A spore of the basidiomycota, produced within and borne on a basidium following nuclear fission and meiosis. Also called and basidiocarp.” (Biology of Plants 7th ed. Peter H. Raven, Pg. G-3)
Ascospores and basidiospores are similar in that they are both spores produced by fungi. These two spores differ in where they are produced and released. The basidiospores are produced by a fungus called Basidiomycete. These spores are discharged from the fungi and once they germinate they produce hypheae which grow out in a circular manner from the original spore. The ascospores are produced by a fungus known as ascomycetes. Due to the processed of meiosis, each ascus will contain eight ascospores.
This is a photo of a species of ascomycetes that is responsible for the release of Ascospores.
Photo found: http://www.clarku.edu/faculty/dhibbett/TFTOL/images/fungi/suIllusstictus.jpg
This is a photo of a Basidiomycete fungus that is responsible for the release of Basidiospores.
Photo found: http://bugs.bio.usyd.edu.au/Mycology/images/Topics/Feeding/Basidiomycete1.jpg
Basidiospore/Basidium
Basidiospore: A sexually produced fungal spore borne on a basidium in the fungi known as basidiomycetes. Basidiospores are produced by the union of the nuclei at the tip of a binucleated segment of a hypha. The resulting zygote then divides by meiosis into four haploid nuclei, each of which migrates to the very tip to be released as a basidiospore. A typical mushroom produces billions of basidiospores. www.thefreedictionary.com/basidiospore Basidium: A small, specialized, club-shaped structure typically bearing four basidiospores at the tips of minute projections in the fungi known as basidiomycetes. The basidium is unique to basidiomycetes and distinguishes them from other kinds of fungi. www.thefreedictionary.com/basidium Both the basidiospore and the basidium are both parts of fungi. The basidiospores are attached to the basidium but serve a different purpose.(Matti Harper)
Basidium/Ascus Basidium:
Club-shaped reproductive cell of the fungal family basidiomycota. Each basidium produces 4 basidiospores through meiosis and nuclear fisson. The basidiospores are borne on stalk-like structures called stigmata. (Raven, 7th ed.)
Basidia and asci are alike in that they are both the site of spore formation in fungi. They are different in that they produce different numbers of spores, four are produced by basidia and eight are produced by asci. They also differ in their shape, basidia are club-shaped while asci saclike structures. Katherine Loewen
Commensalism/Mutualism
Commensalism a relationship between two living organisms where one benefits and the other is not significantly harmed or helped. It is derived from the English word commensal, meaning the sharing of food. An example of commensalism would be epiphytic plants, which depend on a larger host plant for support but which do not derive any nourishment from it.
Mutualism is a biological interaction between individuals of two different species, where both individuals derive a fitness benefit. Similar interactions within a species are known as cooperation. Mutualism may be classified in terms of the closeness of association, the closest being symbiosis, which is often confused with mutualism. One or both species involved in the interaction may be obligate, meaning they cannot survive in the short or long term without the other species. Many plants will function in a voluntary mutualistic relationship as companion plants, providing each other with shelter, fertilization, the repelling of pests, etc. For example, beans may grow up cornstalks as a trellis, while fixing nitrogen in the soil for the corn. Also, the relationship between bees and flowers would be considered mutualistic. The bees get nectar for a food source and the flowers get pollinated so they can reproduce.
http://en.wikipedia.org/wiki/Commensalism
http://en.wikipedia.org/wiki/Mutualism
http://dictionary.reference.com/browse/Commensalism
Krista Neufeld
Ectomycorrhiza/Endomycorrhiza (Jackie Taylor)
Endomycorrhiza: An in soil fungi which penetrates plant root cells. Endomycorrhizae does not form a sheath around the root tip, but does penetrate the root cells. This plant/fungi relationship is known as the mycorrhiza fungi. The fungus is made up of highly branched hyphae.
Ectomycorrhiza: Forms a sheath around the root tip of a plant. A Hartig Net is than formed by the fungus, meaning an inward growth of hyphae penetrates the plant root. The fungus gains carbons and other organic substances from the plant and in return helps the plants take up nutrients and water. It also puts up a defense against parasites and other predators. The fungus mainly infects woody plants and is the type used in most reforestation efforts.
Both funguses’ increases: nutrient uptake, drought resistance, growth rate and protection against some fungal root pathogens in the plant.
Biology of Plants, 7th edition, Peter H. Raven, Glossary pg. 266.
NC State University -http://www.cals.ncsu.edu/course/pp318/profiles/myc/mycorrhizae.htm#endomycorrhizae
Northern Ireland Fungus Group - http://www.nifg.org.uk/ecto.htm
Enhancement:
Ectomycorrhiza is formed usually of Basidiomycetes fungi, and sometimes of Ascomycetes fungi, whereas Endomycorrhiza is formed of Zygomycetes fungi.(Raven, Biology of Plants, pg. 291)
Jake
Epigeous/Hypogeous: (Jackie Taylor) Epigeous – A form of seed germination where the cotyledons are carried above ground level. Ie: Onions, Honeylocust Hypogeous – Form of seed germination where the cotyledons remain underground. They remain underground because elongation occurs above the cotyledon. Ie: Peas, Oaks, Kentucky coffeetree
This photo shows the epigeous germination on the left in the Honeylocust and the hypogeous germination on the right in the Kentucky coffeetree.
University of Kentucky Horticulture - http://www.uky.edu/Ag/Horticulture/kytreewebsite/Propagation/schoolprojects/seedling%20emergence%20project.htm Biology of Plants, 7th edition, Peter H. Raven, Glossary pg. 506-507
Fungus/Lichin Fungus: Any of a group of unicellular, multicellular, or syncytial spore-producing organisms feeding on organic matter, including moulds, yeast, mushrooms, and toadstools. Lichen: Any plant organism of the group Lichens, composed of a fungus and an alae in a symbiotic association, usually of green, grey,or yellow tint and growing on and colouring rocks, tree trunks, roofs, walls,etc.
Heterotroph/ Saprophyte: A heterotroph is an organism that cannot manufacture organic compounds and so must feed on organic materials that have originated in other plants and animals (Raven, Biology of Plants).It is a creature that must ingest biomass to obtain its energy and nutrition. An example of a heterotroph is a human being. Even a few vascular plants are heterotrophic, parasitizing the roots of other plants and thereby obtaining their own nourishment. These plants are known as saprophytes (Science Encyclopedia, Vol 3, Online).A saprophyte is any plant that depends on dead plant or animal tissue for a source of nutrition and metabolic energy. Most do not produce chlorophyll and therefore do not photosynthesize; they are dependent on the food energy they absorb from the decaying tissues, which they help to break down. An example of a saprophyte is mold (The Columbia Encyclopedia, Sixth Edition 2007 Online). A saprophyte is an organism that secures its food directly from nonliving organic matter (Raven, Biology of Plants). Tessa J
Hartig Net/Mantle: (Jackie Taylor) Hartig Net: A highly branched network that surrounds many of the cortical and epidermal cells. Hartig net functions as the interface between the fungus and the plant. It is formed as hyphae from the fungus penetrate the root along the middle lamellae between the root cortical cell walls. Mantle: A sheath of hyphae that covers the root surface. Secretes hormones which cause the root to branch. Both the hartig net and the mantle are produced by the ectomycorrhizae. They involve creating a sheath/covering of hyphae. They differ in that the mantle covers just the root and secrets hormones and the hartig net surrounds the cortical and epidermal cells.
Site name: Ectomycorrhizae information from Smith and Read 1997, Molina, Massicotte and Trappe 1992, Harley and Smith 1983 - http://botit.botany.wisc.edu/courses/mpp/Ectomyco116.html
Host and Parasite - Parasitism is a phenomenon in which two organisms co-exist over a prolonged period of time, usually the lifetime of one of the individuals. A host is an organism that harbors a virus or parasite, typically providing nourishment and shelter. (Centers for Disease Control and Prevention (2004). The Influenza (Flu) Viruses). A parasite, usually physically the smaller of the two, is an organism that lives on the host and derives nutrients from it; the association is beneficial to the parasite and harmful to the host. (Raven. Biology of Plants). An example of this relationship is varroa mites and bee colonies. The mites are the parasites - the beneficial ones, and the bees are the hosts, having their colonies weakened and destroyed by the mites.
Hyphae/Mycelium: Hyphae are the tiny individual filaments that compose a fungus. Hyphae are composed of tubular cell walls surrounding the plasma membrane and cytoplasm of the cells. Hyphae have cell walls composed of chitin, a nitrogen-containing polysaccharide. (Campbell Reece, 7th Edition, pg. 609) Mycelium is the term for the interwoven mass that the hyphae create as they grow. (Raven, G-15) Basically, mycelium is the term we use to refer to the body of the fungus, which is made up of all the interwoven hyphae. Hyphae makes up mycelium, and mycelium is the collective term for all the hyphae.
Amanda M.
Mutualism/Parasite
Mutualism is an interaction between individuals of different species and plays a large role in ecology. This interaction is characterized by the benefit of both species from the relationship, and the increase in their survivorship. One example of this mutualistic relationship is bees and flowers, the bees gather the pollen and as they travel from flower to flower they pollinate them. A flower gets its pollen passed from one individual to another. In turn the flower provides a food reward in the form of nectar, or pollen as a solid food source. A parasite is an organism that may not be closely related to the host organism, but they co-exist indefinitely until one of the organism dies. The parasitism is characterized by one organism (usually the smaller organism) benefits from the host organism that is harmed by the relationship. An example of this parasitic relationship is the hookworm which lives in the intestine of its host, usually a cat or dog. http://www.aber.ac.uk/~mpgwww/Edu/EduIndex.html Begon, M., J.L. Harper and C.R. Townsend. 1996. Ecology: individuals, populations, and communities, Third Edition. Blackwell Science Ltd., Cambridge, Massachusetts, USA. Mike Tomlinson
Enhancement:
Parasitism is a symbiotic relationship where one organism is dependent on the other, but harms its host in the process. It is similar to amensalism, but with amensalism the visitor organism is not necessarily dependent on the host. In contrast, in a true mutualistic sybiotic relationship, both species are dependent on each other, and benefit each other.(The American Heritage® Science Dictionary, http://dictionary.reference.com/browse/Symbiosis)
Jake
Mutualism / Lichen; Lichen – the symbiotic relationship formed by mutualistic association between a fungus and a photosynthetic algae or cyanobacterium (Campbell & Reece, Biology 7th ed. Glossary). Mutualism – a symbiotic relationship in which both participants benefit (Campbell & Reece, Biology 7th ed. Glossary). Lichens are a symbiotic association of millions of photosynthetic microorganisms held in a mass of fungal hyphae, meaning the fungal component is usually an ascomycete and the photosynthetic partner is usually a unicellular or filamentous green algae or cyanobacteria (Campbell & Reece, Biology 7th ed. Pg 621). These structures are involved in the transfer of carbohydrates and nitrogen compounds from the photobiont (the photosynthetic compound of the lichen) to the fungus (Raven, Biology of Plants, pg 290). In english terms, this means that lichen need mutualism with a fungus and a photosynthetic microorganism to live and survive. Stephanie Lauer
Mutualism/Symbiosis (Dennis Murengi) Mutualism: The living together of two or more organisms in an association that is mutually advantageous. (Biology of Plants 7th Edition G-15) Symbiosis: The living together of in close association of two or more dissimilar organisms; includes parasitism (in which the association is harmful to one of the organisms) - Biology of Plants 7th Edition G-23) Both mutualism and symbiosis are similar in that they both involve an association between two or more organisms. However the two relationships differ in that mutualism is a type of symbiosis in which both or all of the organisms involved benefit from the relationship. (www.biology-online.org) http://www.biology-online.org/dictionary/Mutualism Symbiosis on the other, hand also includes parasitism, which is a one-sided relationship whereby one of the symbionts (the parasite) benefits at the expense of the other (the host). (www.eden.rutgers.edu) http://www.eden.rutgers.edu/~tavisa/Symbiosis.html
Mycelium/Mycorrhiza Mycelium: The mass of fine branching tubes (known as hyphae) that forms the main growing structure of a fungus. Visible structures like mushrooms are reproductive structures produced by the mycelium. www.thefreedictionary.com/mycelium Mycorrhiza: The symbiotic association of the mycelium of a fungus with the roots of certain plants, such as conifers, beeches, or orchids. www.answers.com/topic/mycorrhiza Mycorrhiza is the relationship between mycelium and the roots of other plants. (Matti Harper)
Mycorrhizae/Lichen
Mycorrhizae:
Mycorrizhae are a mutually beneficial relationship between the roots of vascular plants and fungi. Nearly all higher plants exhibit this relationship and when are grown without fungi they experience malnutrition and often die. In this relationship the plants benefit through increased uptake of water and nutrients and protection from pathogens while the fungus benefits through transfer of carbohydrates from the plant. (Jennings, D.H. and Lysik G., 1996) and (Freeman 2004)
Lichen:
Lichen are a relationship between a fungus and a green algae or a cyanobacteria. In this relationship the fungus is called the mycobiont and the algae or cyanobacteria is called the photobiont. The fungus and the photobiont are connected by hyphae from the fungus that penetrate the cells of the photobiont, through which the fungus obtains carbohydrates and nitrogen. The photobiont also benefits from this relationship because it is provided with and ideal place to grow. (Freeman 2004)
Lichen and Mycorrhizae are similar in that they are both examples of mutualistic relationships. A mutualistic relationship is when two or more organisms live together in a situation through which they both benefit. They are also similar in that the fungi in both relationships obtains carbohydrates from the other organism. A difference between lichen and mycorrhizae is that mycorrhize are an associaton between a fungus and a plant while a lichen is a relationship between an algae or a cyanobacteria and a fungus.
Katherine Loewen
Mycorrhiza/Parasite (AarenS)
A parasite is an organism that lives in or on a member of a different species and derives nutrients from it, this relationship is beneficial to the parasite and harmful to the host. (Biology of Plants, 7th edition).
A mycorrhiza is a fungus which attaches to the roots of a host of a different species (a tree in this case) and enters a relationship with the host that is beneficial to both the host and the fungi. In this relationship the host provides nutrients in the form of sugars to the fungi, and the fungus provides an increase of surface area which the tree uses to absorb a greater amount of water and nutrients.
Parasites and mycorrhiza are similar in that they both have evolved to be dependant on another organism in order to live and reproduce. Parasites and mycorrhizae differ because while the parasitic relationship benefits only the parasite and harms the host, the mycorrhiza has entered a relationship which is beneficial to both organisms.
Mycorrhiza/Root Hairs
Mycorrhiza: A symbiotic association between certain fungi and plant roots; characteristic of most vascular plants. These symbioses are characterized by bi-directional movement of nutrients where carbon flows to the fungus and inorganic nutrients move to the plant, thereby providing a critical linkage between the plant root and soil. In infertile soils, nutrients taken up by the mycorrhizal fungi can lead to improved plant growth and reproduction. As a result, mycorrhizal plants are often more competitive and better able to tolerate environmental stresses than are nonmycorrhizal plants.
Root Hairs: A tiny extension of a root epidermal cell, growing just behind the root tip and increasing the surface area for absorption of water and minerals. It is a delicate structure, which survives for a few days only and does not develop into a root. Root hair cells are found just behind the root tip where they are continually being formed. They grow out into the soil for a few millimetres to produce the root hair. Each root hair is made of a single cell. At the root tip mitosis cell division is very active making new cells for growth to replace the root hair cells that die.
Mycorrhiza/Zygomycete Mycorrhiza: A symbiotic association between certain fungi and plant roots; characteristic of most vascular plants. These symbioses are characterized by bi-directional movement of nutrients where carbon flows to the fungus and inorganic nutrients move to the plant, thereby providing a critical linkage between the plant root and soil. In infertile soils, nutrients taken up by the mycorrhizal fungi can lead to improved plant growth and reproduction. As a result, mycorrhizal plants are often more competitive and better able to tolerate environmental stresses than are nonmycorrhizal plants. Zygomycete: a fungus (i.e. bread mold) that lives on organic matter or as a parasite. The most common members of the Zygomycota are the fast growing members of the Mucorales. They function as decomposers in soil and dung, thereby playing a significant role in the carbon cycle.
Parasite/Pathogen
Parasite: A parasite is an organism that lives in or on another organism, its host. A parasite is dependent on the host for nourishments and life functions. A parasite usually causes some harm to the host. Two examples of plant species that parasitize on other plants include, mistletoe and parasitic dodder. (MSN Encarta: Online )
Pathogen: A pathogen is a living microorganism that uses another organism, a host, for nourishment, causing illness and disease. Pathogens include various types of bacteria and fungus. (Biology Online org) A parasite and a pathogen share a similar relationship with another organism, or host, using it to obtain nourishment.
The difference between a pathogen and a parasite is the outcome they cause on the host. A parasite causes harm compared to the pathogen that can infect, causing disease or illness.
References: Biology Online Org. Website found: http://www.biology-online.org/dictionary/Pathogens
MSN Encarta:Online. Website found:http://encarta.msn.com/encyclopedia
- Nikki Heim.
Parasite vs. Saprophyte Parasite is an organism that lives on or in the host of a different species. This relationship is harmful to the host because the parasite derives some or all of its nutreints from the host. Saprophyte is an organism that lives on dead organic matter. Both parasites and saprophytes may harm their host. A saprophyte may decay the heartwood of a tree which would weaken the strength of the tree. A parasite may not decay the tree but it will weaken the tree by consuming the nutrient that the tree is manufacturing.
Jessi.E.W
Parasite/Symbiosis
Parasite: An organism that lives on or in a different kind of organism, the host from which it gets some or all of its nourishment. Parasites are generally harmful to their hosts (Raven Glossary. p.16), although the damage they do ranges widely from minor inconvenience to debilitating or fatal disease.
Symbiosis: Symbiosis is a close ecological relationship between the individuals of two or more different species. Sometimes a symbiotic relationship benefits both species, sometimes one species benefits at the other's expense, and in other cases neither species benefits. This relationship includes parasitism and mutualism (advantageous to both) (Raven Glossary. p.23). Parasite is harmful to the host, whereas symbiosis generally benefits the host. Rarely, the symbiosis relationship can be harmful to the host. Tamiki N
http://www.thefreedictionary.com/parasite, http://www.cals.ncsu.edu/course/ent591k/symbiosis.html
Definitions (in alphabetical order) Arbuscular Mycorrhizal (AM) Fungus: The arbuscular mycorrhizal symbiosis is a mutualistic association formed between plants and a wide variety of fungi. Arbuscular mycorrhizae (AM) are the most common type of mycorrhizae on the planet. Ninety percent of all plant families contain AM species, and most mycorrhizasts believe that the vast majority of all land plants (from hornworts to grasses) are AM.The symbiosis is formed by the majority of the vascular flowering plants and is found in ecosystems throughout the world. In general, the symbionts trade nutrients, and the arbuscular mycorrhizal (AM) fungus obtains carbon from the plant while providing the plant with an additional supply of phosphorus (as phosphate). Tamiki NArbuscular mycorrhizal (AM) fungus Tamiki N
arbuscule Jake L
ascomycete
ascospore
ascus
basidiomycete(Daniel Struthers)
basidiospore
basidium
bimodal nutrition
commensalism - Mark Dinicol
ectomycorrhiza=Lacey L
endomycorrhiza
external hyphae(Daniel Struthers)
Gadgil effect - Aaren Secord
Hartig net - Mark Dinicol
heterotrophic(Daniel Struthers)
host - Aaren Secord
hyphae - Mark Dinicol
hypogeous - Aaren Secord
intercellular growth
interface - Scott Horley
intracellular growth= R.Swite
lichen= Lacey L
mantle Jake L
mutualism=R.Swite
mycelium
mycophagy
mycorrhiza-Danielle Dornik
parasite - Scott Horley
pathogen=R.Swite
rhizosphere - Scott Horley
saprophyte Ryan T
symbiosis JAke L
truffle
vesicle=Lacey L
zygomycete
Source: http://www.noble.org/MedicagoHandbook/pdf/ArbuscularMycorrhiza.pdf, http://botit.botany.wisc.edu/courses/mpp/AM.html
Enhancement: Below is a picture of Colonization of a flax root by Arbuscular Mycorrhizal Fungi. The black areas within the root are locations of transfer of phosphorus from the fungus to flax called Arbuscules. In exchange, the fungus obtain food energy from the flax. The thin black strands joining the Arbuscules are also the fungus and these extend into soil increasing the root system of the flax plant.
http://images.google.ca/imgres?imgurl=http://www.umanitoba.ca/afs/graphics/fiw_tenuta_fig2.jpg&imgrefurl=http://www.umanitoba.ca/afs/fiw/060105.html&h=345&w=463&sz=49&hl=en&start=2&um=1&tbnid=EON1k6tSEjPdEM:&tbnh=95&tbnw=128&prev=/images%3Fq%3DArbuscular%2BMycorrhizal%2Bfungi%26svnum%3D10%26um%3D1%26hl%3Den -Nick NArbuscule An arbuscule is hypha that penetrates a root cornical cell, forming a tree-like structure. ( Mycorrhizas: Anatomy and Biology, Peterson, L., et.al. pg. 163) The arbuscule does not enter the protoplast, it surrounds the protoplast, and causes infolding and increasing of the protoplasts area. This increases the transfer of nutrients between the cell that the fungi. The hypha also extends out of the cell into the soil, increasing the absorption of water and nutrients of the cell. (Raven, pg. 292-293) Arbuscules are endomycorrhizae, made up of around 200 species of zygomycota fungi, and inhabit root cells of around 80 percent of vascular plants. This type of mycorrhizal fungi is totally dependent on plants as host cells (obligate biotrophs).(Mycorrhizas: Anatomy and Biology, Peterson, L., et.al. pg. 163) Jake
Enhancement:
Note the distinct tree like shape
http://biology.kenyon.edu/fennessy/SrexMarx/arbgood.jpg
--John
Ascomycete (Caitlin Deas)
The ascomycetes are one of two major groups in the septate fungi (the other is the basidiomycetes). They are septate since their hyphae have cross-walls, or septae. They usually produce a fruiting body (a mushroom-like growth), which produces the spores sexually. The spores (called ascospores) are produced inside little sac-shaped enclosures called asci in a layer in this fruiting body. (Nature Navigator) http://internt.nhm.ac.uk/jobj/runjava.jobj?java=ctol.CTOLServer&method=printNamePage&accountref=987&NAMEID=27084
They also reproduce asexually by forming nonsexual spores (conidia) at the ends of their hyphae. Some examples of ascomycetes are yeasts, morels, truffles, Dutch elm disease and ergot. (The Free Dictionary by Farlex) http://www.thefreedictionary.com/ascomycete
There are 15,000 species in 1,950 genera of ascomycetes. The lichens form the largest group. (The Free Dictionary by Farlex)http://encyclopedia.farlex.com/ascomycete
This is a picture of orange-peel fungus, Aleuria aurantia,a non-lichenised ascomycete fungus.
(Fathom)
http://www.fathom.com/feature/122560/3051_lichen9_SM.jpg
Ascospore: Type of sexual spore produced within the ascus; found in ascomycetes. 4-8 spores are produced in the Ascomycetes and are capable of asexual reproduction Biology of plants 7th edition http://www.britannica.com -Travis Unsworth
Enhancement(Andrea Chapman) Ascospores through an Electron Micrograph (AFTOL Project - http://www.clarku.edu/faculty/dhibbett/TFTOL/images/ascospore.jpg)
Enhancment(Jackie Taylor) - They are haploid cells formed after meiosis. Ascospores are unique structures that distinguish the ascomycetes from all other fungi. They are recognizable by the fact that they have no attachment points, and are sometimes enclosed in gelatinous sheaths or within a sac. Produced by morels, truffles, cup fungi, ergot and many micro-fungi. Biology of Plants, 7th edition, Peter H. Raven, Glossary pg. 271-272 EM Lab P&K - https://www.emlab.com/app/fungi/Fungi.po?event=fungi&species=4&type=secondary
Ascus (Caitlin Deas)
The ascus is a sac-shaped enclosure in the fruiting body of an ascomycete. It contains the sexual ascospores, which are formed by an enveloping membrane system. In this system, mitosis follows meiosis to form eight nuclei, which become eight ascospores eventually. Below is a picture of Taphrina, the asci of the peach leaf curl fungus atop a peach leaf.
(Tree of Life Web Project)
http://www.tolweb.org/Ascomycota
Although the ascus usually generates only eight ascospores, there are some that produce many more (even thousands). (Illinois Mycological Association) http://www.ilmyco.gen.chicago.il.us/Terms/ascus134.html
Enhancement: The ascus is a saclike structure produced by fungi of the class Ascomycetes (sac fungi) in which sexually produced spores (ascospores), usually four or eight in number, are formed. Asci may arise from the fungal mycelium (the filaments, or hyphae, constituting the organism) without a distinct fruiting structure, as in the leaf curl fungi; it may arise within a fruiting structure (ascocarp) that may be exposed, as in the molds and powdery mildew fungi; or it may be imbedded in a compact structure (stroma), as in the ergot and black knot fungi. In the case of yeasts, a single cell converts to an ascus. (Encyclopedia Britannica Online, http://www.britannica.com/eb/article-9000538/ascus ). Lee Williams.
Basidiospore:
Spores produced by fungi in the family Basidiomycota (Raven, 7th ed.). Basidiospores are produced by reproductive cells called basidia through meiosis and nuclear fisson. They are uninucleate and haploid. When basidiospores are discharged they germinate to form the primary mycelia of a new fungus. (Introductory Mycology. Alexopoulos, C.J. and Mims, C.W., 1979) (Raven, 7th ed.)
Katherine Loewen
The arrow points to an example of a basidiospore. www.botany.hawaii.edu (Matti Harper)Basidiospore (Enhancement) - When basidiospores encounter a favorable substrate, they may germinate, typically by forming hyphae. These hyphae grow outward from the original spore, forming an expanding circle of mycelium. Some basidiospores germinate repetitively by forming small spores instead of hyphae. (Tree of Life: Basidiomycota). Atypical mushroom produces billions of basidiospores. (The American Heritage Science Dictionary).
- Mark Dinicol
Basidium:
Club-shaped reproductive cell of the fungal family basidiomycota. Each basidium produces 4 basidiospores through meiosis and nuclear fisson. The basidiospores are borne on stalk-like structures called stigmata. (Raven, 7th ed.) (Introductory Mycology. Alexopoulos, C.J. and Mims, C.W., 1979)
Katherine Loewen
Basidium (Enhancemen)t: A reproductive appendage that produces sexual spores on the gills of mushrooms. (Biology 7th Edition, Campbell and Reece, pg. 618) Lacey Loewen
Basidium (Enhancement) - a microscopic, spore-producing structure found on the hymenophore of fruiting bodies of basidiomycete fungi. The basidium is unique to basidiomycetes and distinguishes them from other kinds of fungi. (The American Heritage® Science Dictionary)
Most basidiomycetes have single celled basidia, but in some groups basidia can be multicellular. (Ingold, 1998. Ballistosporic basidia).
Scanning electron micrograph of basidia on the gills of a toadstool. Note that each basidium produces four stalks (sterigmata) and the basidiospores develop on the ends of these stalks. (The Microbial World: Basidiomycota)
-Mark Dinicol
Commensalism -term used to describe a relationship between two living organisms where one benefits and the other is not significantly harmed or helped. (H.T. Baumgarten & K. Fiedler 1998. Parasitoids of lycaenid butterfly caterpillars). Some biologists argue that any close interaction between two organisms is unlikely to be completely neutral for either party, and that relationships identified as commensal are likely mutualistic or parasitic in a subtle way that has not been detected. (Benzing, D.H. 1980. Biology of the Bromeliads.)
The relationship of barnacles on gray whales is an example of commensalism
-Mark Dinicol
Enhancement = commensalism RSwite
A mutualistic relationship where one individual benefits while the other is neither harmed nor benefited. For example, the dung beetle relies on the scat of the gopher tortoise which it crafts into a ball and rolls to a location where it can be eaten later. ...
www.auburn.edu/academic/forestry_wildlife/longleafalliance/teachers/teacherkit/glossary.htm A mutualistic relationship where one individual benefits while the other is neither harmed nor benefited. For example, the dung beetle relies on the scat of the gopher tortoise which it crafts into a ball and rolls to a location where it can be eaten later. ...
www.auburn.edu/academic/forestry_wildlife/longleafalliance/teachers/teacherkit/glossary.htm Commensialism means literally 'at table together'. This is a symbiotic relationship between two species in which one species benefits and the other neither benefits or harms. Often, the host species provides a home and/or transportation for the other species. http://www.botany.uwc.ac.za/sci_ed/grade10/ecology/symbiosis/commen.htm
Endomycorrhiza: The mass of hyphae forming the body of a fungus, oomycete, or chytrid. Endomycorrhizae does not form a fungal sheath around the root like ectomycorrhizae does, but it penetrates the cortical cells but doesn’t penetrate the cell membrane- Travis Unsworth http://www.uwlax.edu/biology Biology of Plants 7th Edition
Endomycorrhizae are in soil fungi's which pernetrate plant root cells and increases both the plants and fungi's uptake of nutrients. This plant/fungi relationship is known as the mycorrhiza fungi. (Jackie Taylor)
http://www.nrp48.ch/projects/projects_detail.php?nfprojnum=17&isactdescr=yes Biology of Plants, 7th edition, Peter H. Raven, Glossary pg. 266.
Hartig net - a complex network of fungal hyphae that is the site of nutrient exchange between the fungus and the host plant. (McGraw-Hill Dictionary of Scientific and Technical Terms 2003). It is formed in ectomycorrhizae by hyphae which grow between the cells of the root epidermis and cortex. The Hartig net eventually surrounds many of the cortical and epidermal cells. In the roots of most angiosperms colonized by ectomycorrhizal fungi, the epidermal cells are triggered to enlarge primarily at right angles to the surface of the root, thickening the root rather than extending it, and the Hartig net is confined to this layer. (Raven. Biology of Plants 2005.)
Diagram of typical ectomycorrhiza including the Hartig net, fungal mantle and external hyphae
- Mark Dinicol
Hyphae - long slender tubes that develop from germinated spores and form the structural parts of the body of a fungus. (Martinko J. 2005. Brock Biology of Microorganisms). In many species of fungi, hyphae are divided into sections by cross walls called septa. Each section contains at least one haploid nucleus, and the septa usually have perforations that allow cytoplasm to flow through the hypha. A large mass of hyphae is known as a mycelium, which is the growing form of most fungi. (The American Heritage Science Dictionary. 2005).
Hyphae of Penicillium
- Mark Dinicol
Enhancement (Hyphae): The vast majority of fungi are filamentous and the vegetative stage is a cylindrical thread-like filament called a hypha. Most hyphae are 2-10 um across, and cannot be resolved by the naked eye. The hyphal wall is quite tough, and composed of mainly of chitin (www.uoguelph.ca/~gbarron/MISCELLANEOUS/hyphae.htm). Hyphae contain nuclei, mithochondria, robosomes, Golgi and membrane-bound vesicles within a plasma-membrane bound cytoplasm (MicrobiologyBytes 2007, online). Tessa J Enhancement – Jessi.E.W There are three different types of hyphae which include generative hypha, skeletal hypha and binding hypha. If all three are present in the fungi then the fungi is termed polypore hyphae.
Host (AarenS)
A host is an organism that is being predated upon by a parasite, which is an organism that is dependant upon the host to live, grow, and multiply. A host in such a relationship does not benefit from the relationship, but is instead harmed by the parasite in various ways and can even be killed by the relationship it has with the parasite. Examples could be a tree or shrub acting as host to a mistletoe (parasitic plant from the order santalales seen below) which does not end until the death of either the host or the parasite, a human being bit by a mosquito which is a form of parasitism that does not last very long, or a vertibrate carrying a tape worm.
(Biology of Plants, 7th edition)
(http://www.science.siu.edu/parasitic-plants/)
Enhancement (Stephanie Lauer): a host is the larger participant in a symbiotic relationship, serving as a home and feeding ground to the symbiont (the smaller participant in the symbiotic relationship). Symbiotic relationships are classified as either mutualism, commensalism or parasitism. In mutualism both of the organims are benefit, in commensalism one organism benefits while the neither helping nor harming the other in any significant way and a parasitism mean one organism benefits at the cost of the other (Campbell & Reece, Biology 7th ed. pg 545)
Intracellular growth = RSwite Plant cells engage in mutualistic and parasitic endosymbioses with a wide variety of microoganisms, ranging from Gram-negative (Rhizobium, Nostoc) and Gram-positive bacteria (Frankia), to oomycetes (Phytophthora), Chytridiomycetes, Zygomycetes (arbuscular mycorrhizal fungi) and true fungi (Erysiphe, ascomycete; Puccinia, basidiomycete). Endosymbiosis is characterised by the 'symbiosome', a compartment within host cells in which the symbiotic microorganism is either partially or completely enclosed by a host-derived membrane. The analysis of plant mutants indicates that the genetic requirements for the interaction with rhizobia and arbuscular mycorrhiza fungi are partially overlapping. The extent to which plants use similar or identical developmental programs for the intracellular accommodation of different microorganisms is, however, not clear. For example, plant cells actively weaken their cell wall to facilitate bacterial colonisation, whereas penetration by fungal symbionts appears not to be assisted in this manner. Moreover, different transport requirements are imposed on the symbiotic interface of different interactions indicating that additional system-specific components are likely to exist. http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6VS4-40NMR23-C&_user=10&_coverDate=08%2F01%2F2000&_rdoc=1&_fmt=&_orig=search&_sort=d&view=c&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=e5a654926bf1378c54faebda2d237828
Figure 1 Here is a piture showing how cells interact with one another when it
comes to intracellular growth and nutrient sharing. www.emc.maricopa.edu/.../BIOBK/waterflow.gif
RSwite
Mantle The mantle, or fungal mantle, is a sheath or net-like mesh of fungal hyphae that forms around roots. This sheath like fungus is generally ectomychorizae, and is comprised of mainly bacidiomycetes fungi, and less often ascomycetes fungi. Certain hormones are secreted by the fungi of the mantle that may cause the root to branch. (Raven, pg. 292-293) The hyphae of the inner mantle make up the hartig net, which is a complex nutrient transfer system between both cortex and epidermal cells. The fungal mantle increases the absorption of water and nutrients of the root system, benefiting the plant.( Mycorrhizas: Anatomy and Biology, Peterson, L., et.al. pg. 22,163) Jake
Enhancement (Nicole L) This is a picture of fungal mantle surrounding roots of a plant host
Image from ocid.nacse.org/.../bot461/imghtm/ectotips.htm
Mutualism The relation between two different species of organisms that are interdependent; each gains benefits from the other. A type of symbiosis where two (or more) organisms from different species live in close proximity to one another and rely on one another for nutrients, protectio, or other lif funcitons. Both (or all) of the organisms invloved benefit from the relationship. http://www.biology-online.org/dictionary/Mutualism a relationship between two organisms of different species that benefits both and harms neither. For example, lichens are a fungus and an alga living in mutualism: The fungus provides a protective structure, and the alga produces a carbohydrate as food for the fungus. http://encarta.msn.com/dictionary_/mutualistic.html R.Swite
Enhancement: Amanda Last Mutualism: association between organisms of two different species in which each is benefited. Mutualistic arrangements are most likely to develop between organisms with widely differing living requirements. The partnership between nitrogen-fixing bacteria and leguminous plants is an example, as is the association between cows and rumen bacteria (the bacteria live in the digestive tract and help digest the plants eaten by the cow). The associations between tree roots and certain fungi are often mutualistic.(Britannica Online Encyclopedia). The relationship existing between two organisms of different species which contribute mutually to each other's well-being; an instance of this.(Oxford English Dictionary).
Enhacement:
As seen in the picture, mycorrizal fungi benefits the plant by increasing its absorbance surface area.It is benafitted by food it obtains from the plant.Both cannot live properly without each other.
(Plant Health Care.co.uk,http://www.planthealth care.co.uk/images/fungi.gif)
(Raven, Biology of plants, pg. 291)
Jake
Mycelium: Mass of hyphae that constitutes the vegetative part of a fungus. The mycelium makes up the thallus, or undifferentiated body, of a typical fungus. It may be microscopic in size or developed into visible structures, such as brackets, mushrooms, puffballs, rhizomorphs http://cancerweb.ncl.ac.uk/cgi-bin/omd?mycelium http://www.britannica.com Travis Unsworth
Enhancement (Andrea Chapman) Armillaria root rot (Armillaria ostoyae) is a common fungus found in British Columbia’s forests that is easily identifiable by its mycelial fans. These fans are a white/creamy colour and found under the bark at the base of the stump and roots (Cruickshank et al. 1997).
Cruickshank M.G., Morrison D.J., and Punja Z. K. 1997. Incidence of Armillaria species in precommercial thinning stumps and spread of Armillaria ostoyae to adjacent Douglas-fir trees. Canadian Journal of Forest Research 27: 481-490
Enhancement (Nick N) This is a picture of mycelium growing on a decomposed log.www.ipm.iastate.edu/.../2006/4-5/fungi.html
Parasite: A parasite is something that lives in dependence of another organism in order to maintain its existence. These organisms do not give back to the host that they feed from. Instead they usually cause harm, but rarely do they kill the host. The parasite has to be in its host to live, grow and multiply. A common, well-known type of a parasite is a hookworm. Hookworms can be commonly found in mammals, most commonly humans and domestic animals. Hookworms attach themselves in the lining of the small intestine, and cause diseases, and malnutrition as well, as they eat the nutrients and keep them from going to the host.
Fig.1: a common parasite, the hookworm. Found in the small
intestine of humans and their domestic animals.
References: http://student.biology.arizona.edu/honors98/group15/whatisaparasite.htm
http://www.m-w.com/dictionary/parasite
http://phil.cdc.gov/phil/home.asp
Public Health Image Library] Image #5205
-Scott Horley
Parasite (enhancement) - Parasites that live inside the live body of the host are called endoparasites (e.g., hookworms that live in the host's gut), and those that live on the outside are called ectoparasites (e.g., some mites). (Zimmer, Carl 2001. Parasite Rex) .Many endoparasites acquire hosts by gaining entrance to their tissue; others enter the host when it consumes certain raw foods. Ectoparasites, on the other hand, often have elaborate mechanisms and strategies for finding hosts. Some aquatic leeches, for example, locate hosts by sensing movement and then confirm their identity through skin temperature and chemical cues before attaching. (The American Heritage® Science Dictionary)
Mites parasitising a harvestman
- Mark Dinicol
Pathogen
Pathogen: An agent of disease. A disease producer. The term pathogen most commonly is used to refer to infectious organisms. These include bacteria, viruses , and fungi. Less commonly, pathogen refers to a noninfectious agent of disease such as a chemical. http://dendroglossary.wetpaint.com/page/Symbiotic+Associations%3B+Mycorrhial+Fungi+and+Mycorrhizae A disease producing organisms that can exist in many different places. (for example: air, dust, counter top surface, the body, etc.) A pathogen or infectious agent is a biological agent that causes diseaseor illness to its host. The term is most often used for agents that disrupt the normal phisiology of a multicellular animal or plant. however, pathogens can infect unicellular organisms from all of the biological kingdoms. http://www.biology-online.org/dictionary/Pathogens R.Swite
www.scielo.br/img/fbpe/fb/v27n4/a17fig01.gif
A picture showing the effects that some pathogen have on trees.R.Swite Enhancement: Pathogens are identified by the hosts they infect and the symptoms they cause; it is also important to identify the specific properties of the pathogen that contribute to its infectious capacity—a characteristic known as virulence. http://www.britannica.com/eb/article-216178/microbiology Travis Unsworth
Rhizoshere:
The Rhizosphere is the area that surrounds the roots of plants. The Rhizosphere is directly influenced by the root’s secretions, the soil microorganisms and the soil itself. The root of the plant and the biofilm of the root can greatly influence the soil. The Rhizosphere can change the soils pH and nitrogen transformations by crowding the bacteria from the sloughed-off plant cells as well as the proteins and sugars the root releases.
Ref:
http://www.regional.org.au/au/allelopathy/2005/2/3/2535_fujiiy.htm?print=1
http://uwstudentweb.uwyo.edu/T/Twhite/
-Scott Horley Enhancement = rhizosphere RSwite The soil zone that surrounds and is influenced by the roots of plants. Within the rhizosphere, roots secrete a slimy lubricating substance, called mucigel, that cause the particles of soil to adhere to the roots, assisting in the uptake of water, and encourages the growth of nitrogen-fixing bacteria and other beneficial microorganisms. http://www.thefreedictionary.com/rhizosphere...The area immediately surrounding plant roots that is responsible for creating the conditions of this micro-habitat when taking into account the properties and actions of the plant. http://www.biology-online.org/dictionary/Rhizosphere RSWITE
Saprophyte: An organism, that obtains food by breaking down organic matter into simple compounds and absorbs nutrients from those compounds. Saprophytes include mainly fungi and bacteria, but also include molds, actinomycetes, and a select few plants and animals. (Ryan T)
http://www.bookrags.com/research/saprophyte-enve-02/ (para1
http://dictionary.reference.com/browse/Saprophyte (def #'s 2 & 5)
Enhancement –Saprophyte decomposing dead wood. fungifest.com Jessi.E.W
Enhancement = Saprophyte RSwite Any plant growing on decayed animal or vegetable matter, as most fungi and some flowering plants with no green color, as the Indian pipe. http://dict.die.net/saprophyte/ An organism, especially a fungus or bacterium, that grows on and derives its nourishment from dead or decaying organic matter. http://www.answers.com/topic/saprophyte?cat=health
Symbiosis Meaning derived from the Greek word symbiosis meaning “a living together”. (Online Etymology Dictionary, http://dictionary.reference.com/browse/Symbiosis) This term is used to describe a close association, or bond between two or more organisms of different species, often but not always benefiting each partner. An example of a symbiotic relationship is of Lichen (fungi) and Bacteria. (The American Heritage® Science Dictionary.) http://dictionary.reference.com/browse/Symbiosis) There are four types of symbiotic relationships, Mutualism, (which is a mutually beneficial relationship where each is dependent on other organism), Commensalism , (not a dependent relationship, but is mutually beneficial), Paratism, (where a parasite is dependent on its host, but harms it in the process), and amensalism,(much like parasitism: a relationship where one organism is benefited and the other is inhibited or harmed). (The American Heritage® Science Dictionary, http://dictionary.reference.com/browse/Symbiosis)( Online Etymology Dictionary, http://dictionary.reference.com/browse/Symbiosis) Jake
Enhancement: By Conyr A.
This photo shows a symbiotic relationship between a young tree and a fully developed tree. In this case it would be considered an amensalism relationship because only the smaller tree benefits from growing off the developed one. (Image from: istockphoto.com at the address http://www1.istockphoto.com/file_thumbview_approve/190375/2/istockphoto_190375_symbiosis.jpg) Zygomycete (Caitlin Deas)
A fungus, such as bread mold, that lives on organic matter or as a parasite, in the ClassZygomycetes. (Encarta)
http://encarta.msn.com/dictionary_561563378/zygomycete.html Zygomycetes have hyphae that are continuous tubes, without cross-walls. They are one of two major groups of the aseptate fungi (the other group is the chytrids).
(Nature Navigator)
http://internt.nhm.ac.uk/jobj/runjava.jobj?java=ctol.CTOLServer&method=printNamePage&accountref=987&NAMEID=27087
Below are two examples of zygomycetes. The first is Pilaira anomala on deer feces. The second is Phycomyces blakesleeanus
(Cornell Mushroom Blog)
http://hosts.cce.cornell.edu/mushroom_blog/index.php?paged=3
(JGI)
http://genome.jgi-psf.org/Phybl1/Phybl1.home.html
Enhancement: Terrestrial saprobes or parasites of plants, animals, or humans; asexual reproduction by aplanospores (nonmotile spores) in sporangia or by conidia; sexual reproduction by fusion of morphologically similar gametangia, sometimes differing in size, resulting in thick-walled zygospores. (Encyclopedia Britannica Online, http://www.britannica.com/eb/article-57977/fungus ). Lee Williams.
Compare and Contrast (first word alphabetical)
Arbuscule/Mantle An arbuscule is a hypha that penetrates a roots cornical cell, and froms a tree- like web around the cortex. The Fungal mantle surrounds s the outside of the tree root in a sheath like mass of fungal hyphae. Both fungi help in the absorption of water and nutrients and transfer them to the trees roots. Both structures “surround” organ and transfer substances. They differ in that the arbuscule penetrates a cell, and the mantle surrounds the outside. An arbuscule is endomycorrhizea, formed of around 200 species of zygomycotic fungi and live in 80% of vascular plant roots; whereas, the mantle, which is ectomycorrhizea, is generally made of bacidiomycetes or ascomycetes fungi, and are generally found on the roots of certain groups of trees and shrubs, and are generally quite species specific. There are around 5000 species of fungi in ectomycorrhizal associations. (Raven, pg. 292-293) An arbuscule, or endomycorrizal fungi is dependent on a host cell and cannot by cultured on its own, whereas the mantle fungi can be cultured on its own. (Mycorrhizas: Anatomy and Biology, Peterson, L., et.al. pg. 163) Jake
Ascus/Ascospore (Dennis Murengi) Ascus: A specialised cell, characteristic of the ascomycetes, in which two of the haploid nuclei fuse to produce a zygote that immediately divides by meiosis; at maturity, an ascus contains ascospores. (Biology of Plants 7th Edition G-3) Ascospore: A spore produced within an ascus; found in ascomycetes. (Biology of Plants 7th Edition G-3) Both the ascus and ascospore are found in a type of fungi called ascomycetes. (Biology of Plants 7th Edition, Pg 271) However ascus and ascospore differ in their structure. The ascus has a saclike structure while the ascospores are spores formed inside the ascus. (Biology of Plants 7th Edition, Pg 271)
The image above shows an ascus which contains ascospores. (www.tolweb.org) http://www.tolweb.org/Ascomycota
Ascomycete/ Ascospore: Ascomycete: any of a subdivision (Ascomycotina) of fungi, including the mildews, yeasts, and truffles, that produce spores in asci; sac fungus. www.yourdictionary.com/ascomycete Ascospore:
| A sexual spore from certain fungus species in which spores are found in a sac called an ascus. Haploid spores found in the asci of Ascomycete fungi. |
www.biochem.northwestern.edu/holmgren/Glossary/Definitions/Def-A/ascospore.html Ascomycete and ascospores both exist in fungi while ascospores are the product of ascomycete. (Matti Harper)
Ascomycete/Ascus: An ascus is a saclike structure containing ascospores and usually borne in a fungal fruiting body (APSnet, Plant Pathology Online). Asci are produced by fungi of the class Ascomycetes (Encyclopaedia Britannica, Online). An ascospore is a sexual spore from certain fungus species in which spores are found in a sac called an ascus. Haploid spores found in the asci of Ascomycete fungi (Merriam-Webster’s Dictionary, Online). There are eight such spores in each ascus. The ascospores are released in the atmosphere when slight fluctuations of the relative humidity cause a rupture in the top extremity of the asci (Institut National de la Recherche Agronomique, Pathology). Tessa J
Ascomycetes and Basidiomycetes - species belonging to the two large phyla Basidiomycota and Ascomycota, which together comprise the subkingdom Dikarya, also refered to as the "Higher Fungi" within the Kingdom Fungi. (Moore, R.T. (1980). "Taxonomic proposals for the classification of...). Basidiomycota include mushrooms, puffballs, stinkhorns, bracket fungi, other polypores, jelly fungi etc. They are filamentous fungi composed of hyphae and reproduce sexually via speicalized end cells, however some can reproduce asexually. Ascomycota are commonly known as the "Sac Fungi", with some familiar examples being morels, truffles, Baker's yeast, cup fungi, and the majority of lichens. When reproducing sexually, they produce nonmotile spores in a distinct cell called an "ascus". However, some do not reproduce sexually. (John W. 1996. "Ascomycota", Tree of Life).
Some examples of basidiomycetes. Scarlet Elf Cap growing on oak twigs is an example of an acomycetes.
- Mark Dinicol Ascomycete / zygomycete: Ascomycete are fungus in the phylum Ascomycota characterized by the presence of sexually produced spores formed within an ascus. The nature of hyphae is Septate, their method of asexual reproduction is by budding, conidia(nonmotile spores) and fragmentation and their type of sexual spore is an ascospore.Some common plant diseases cause by ascomycete are powdery mildew, brown rot of stone fruits, chestnut blight and Dutch elm disease. Zygomycete are fungus from the Zygomycota phylum. The nature of hyphae is aseptate and coenocytic, method of asexual reproduction is nonmotile spores(sporangiospores), the type of sexual spore is a zygospore(in zygosporangium), and they cause soft rot of various plant parts. (http://www.thefreedictionary.com/ascomycete) (Biology of Plants P. 263)
-VanessaV
Ascospore/Basidiospore (Jessica Wrench)
Ascospore- “A spore produced within the ascus; found in ascomycetes.” (Biology of Plants 7th ed. Peter H. Raven, Pg. G-3)
Basidiospore- “A spore of the basidiomycota, produced within and borne on a basidium following nuclear fission and meiosis. Also called and basidiocarp.” (Biology of Plants 7th ed. Peter H. Raven, Pg. G-3)
Ascospores and basidiospores are similar in that they are both spores produced by fungi. These two spores differ in where they are produced and released. The basidiospores are produced by a fungus called Basidiomycete. These spores are discharged from the fungi and once they germinate they produce hypheae which grow out in a circular manner from the original spore. The ascospores are produced by a fungus known as ascomycetes. Due to the processed of meiosis, each ascus will contain eight ascospores.
This is a photo of a species of ascomycetes that is responsible for the release of Ascospores.
Photo found: http://www.clarku.edu/faculty/dhibbett/TFTOL/images/fungi/suIllusstictus.jpg
This is a photo of a Basidiomycete fungus that is responsible for the release of Basidiospores.
Photo found: http://bugs.bio.usyd.edu.au/Mycology/images/Topics/Feeding/Basidiomycete1.jpg
Basidiospore/Basidium
Basidiospore: A sexually produced fungal spore borne on a basidium in the fungi known as basidiomycetes. Basidiospores are produced by the union of the nuclei at the tip of a binucleated segment of a hypha. The resulting zygote then divides by meiosis into four haploid nuclei, each of which migrates to the very tip to be released as a basidiospore. A typical mushroom produces billions of basidiospores. www.thefreedictionary.com/basidiospore Basidium: A small, specialized, club-shaped structure typically bearing four basidiospores at the tips of minute projections in the fungi known as basidiomycetes. The basidium is unique to basidiomycetes and distinguishes them from other kinds of fungi. www.thefreedictionary.com/basidium Both the basidiospore and the basidium are both parts of fungi. The basidiospores are attached to the basidium but serve a different purpose.(Matti Harper)
Basidium/Ascus Basidium:
Club-shaped reproductive cell of the fungal family basidiomycota. Each basidium produces 4 basidiospores through meiosis and nuclear fisson. The basidiospores are borne on stalk-like structures called stigmata. (Raven, 7th ed.)
Ascus:
Site of spore formation in ascomycetes. The ascus is a saclike cell that bursts at maturity releasing eight ascospores. Asci are formed at the tips of hyphae on the inner layer of a structure called the ascoma. (Introductory Mycology. Alexopoulos, C.J. and Mims, C.W., 1979)
Basidia and asci are alike in that they are both the site of spore formation in fungi. They are different in that they produce different numbers of spores, four are produced by basidia and eight are produced by asci. They also differ in their shape, basidia are club-shaped while asci saclike structures. Katherine Loewen
Commensalism/Mutualism
Commensalism a relationship between two living organisms where one benefits and the other is not significantly harmed or helped. It is derived from the English word commensal, meaning the sharing of food. An example of commensalism would be epiphytic plants, which depend on a larger host plant for support but which do not derive any nourishment from it.
Mutualism is a biological interaction between individuals of two different species, where both individuals derive a fitness benefit. Similar interactions within a species are known as cooperation. Mutualism may be classified in terms of the closeness of association, the closest being symbiosis, which is often confused with mutualism. One or both species involved in the interaction may be obligate, meaning they cannot survive in the short or long term without the other species. Many plants will function in a voluntary mutualistic relationship as companion plants, providing each other with shelter, fertilization, the repelling of pests, etc. For example, beans may grow up cornstalks as a trellis, while fixing nitrogen in the soil for the corn. Also, the relationship between bees and flowers would be considered mutualistic. The bees get nectar for a food source and the flowers get pollinated so they can reproduce.
http://en.wikipedia.org/wiki/Commensalism
http://en.wikipedia.org/wiki/Mutualism
http://dictionary.reference.com/browse/Commensalism
Krista Neufeld
Ectomycorrhiza/Endomycorrhiza (Jackie Taylor)
Endomycorrhiza: An in soil fungi which penetrates plant root cells. Endomycorrhizae does not form a sheath around the root tip, but does penetrate the root cells. This plant/fungi relationship is known as the mycorrhiza fungi. The fungus is made up of highly branched hyphae.
Ectomycorrhiza: Forms a sheath around the root tip of a plant. A Hartig Net is than formed by the fungus, meaning an inward growth of hyphae penetrates the plant root. The fungus gains carbons and other organic substances from the plant and in return helps the plants take up nutrients and water. It also puts up a defense against parasites and other predators. The fungus mainly infects woody plants and is the type used in most reforestation efforts.
Both funguses’ increases: nutrient uptake, drought resistance, growth rate and protection against some fungal root pathogens in the plant.
Biology of Plants, 7th edition, Peter H. Raven, Glossary pg. 266.
NC State University -http://www.cals.ncsu.edu/course/pp318/profiles/myc/mycorrhizae.htm#endomycorrhizae
Northern Ireland Fungus Group - http://www.nifg.org.uk/ecto.htm
Enhancement:
Ectomycorrhiza is formed usually of Basidiomycetes fungi, and sometimes of Ascomycetes fungi, whereas Endomycorrhiza is formed of Zygomycetes fungi.(Raven, Biology of Plants, pg. 291)
Jake
Epigeous/Hypogeous: (Jackie Taylor) Epigeous – A form of seed germination where the cotyledons are carried above ground level. Ie: Onions, Honeylocust Hypogeous – Form of seed germination where the cotyledons remain underground. They remain underground because elongation occurs above the cotyledon. Ie: Peas, Oaks, Kentucky coffeetree
This photo shows the epigeous germination on the left in the Honeylocust and the hypogeous germination on the right in the Kentucky coffeetree.
University of Kentucky Horticulture - http://www.uky.edu/Ag/Horticulture/kytreewebsite/Propagation/schoolprojects/seedling%20emergence%20project.htm Biology of Plants, 7th edition, Peter H. Raven, Glossary pg. 506-507
Fungus/Lichin Fungus: Any of a group of unicellular, multicellular, or syncytial spore-producing organisms feeding on organic matter, including moulds, yeast, mushrooms, and toadstools. Lichen: Any plant organism of the group Lichens, composed of a fungus and an alae in a symbiotic association, usually of green, grey,or yellow tint and growing on and colouring rocks, tree trunks, roofs, walls,etc.
Heterotroph/ Saprophyte: A heterotroph is an organism that cannot manufacture organic compounds and so must feed on organic materials that have originated in other plants and animals (Raven, Biology of Plants).It is a creature that must ingest biomass to obtain its energy and nutrition. An example of a heterotroph is a human being. Even a few vascular plants are heterotrophic, parasitizing the roots of other plants and thereby obtaining their own nourishment. These plants are known as saprophytes (Science Encyclopedia, Vol 3, Online).A saprophyte is any plant that depends on dead plant or animal tissue for a source of nutrition and metabolic energy. Most do not produce chlorophyll and therefore do not photosynthesize; they are dependent on the food energy they absorb from the decaying tissues, which they help to break down. An example of a saprophyte is mold (The Columbia Encyclopedia, Sixth Edition 2007 Online). A saprophyte is an organism that secures its food directly from nonliving organic matter (Raven, Biology of Plants). Tessa J
Hartig Net/Mantle: (Jackie Taylor) Hartig Net: A highly branched network that surrounds many of the cortical and epidermal cells. Hartig net functions as the interface between the fungus and the plant. It is formed as hyphae from the fungus penetrate the root along the middle lamellae between the root cortical cell walls. Mantle: A sheath of hyphae that covers the root surface. Secretes hormones which cause the root to branch. Both the hartig net and the mantle are produced by the ectomycorrhizae. They involve creating a sheath/covering of hyphae. They differ in that the mantle covers just the root and secrets hormones and the hartig net surrounds the cortical and epidermal cells.
Site name: Ectomycorrhizae information from Smith and Read 1997, Molina, Massicotte and Trappe 1992, Harley and Smith 1983 - http://botit.botany.wisc.edu/courses/mpp/Ectomyco116.html
Host and Parasite - Parasitism is a phenomenon in which two organisms co-exist over a prolonged period of time, usually the lifetime of one of the individuals. A host is an organism that harbors a virus or parasite, typically providing nourishment and shelter. (Centers for Disease Control and Prevention (2004). The Influenza (Flu) Viruses). A parasite, usually physically the smaller of the two, is an organism that lives on the host and derives nutrients from it; the association is beneficial to the parasite and harmful to the host. (Raven. Biology of Plants). An example of this relationship is varroa mites and bee colonies. The mites are the parasites - the beneficial ones, and the bees are the hosts, having their colonies weakened and destroyed by the mites.
LTSEM Microscope image of Varroa mite destructor on a honey bee host.
- Mark Dinicol
- Mark Dinicol
Hyphae/Mycelium: Hyphae are the tiny individual filaments that compose a fungus. Hyphae are composed of tubular cell walls surrounding the plasma membrane and cytoplasm of the cells. Hyphae have cell walls composed of chitin, a nitrogen-containing polysaccharide. (Campbell Reece, 7th Edition, pg. 609) Mycelium is the term for the interwoven mass that the hyphae create as they grow. (Raven, G-15) Basically, mycelium is the term we use to refer to the body of the fungus, which is made up of all the interwoven hyphae. Hyphae makes up mycelium, and mycelium is the collective term for all the hyphae.
Amanda M.
Mutualism/Parasite
Mutualism is an interaction between individuals of different species and plays a large role in ecology. This interaction is characterized by the benefit of both species from the relationship, and the increase in their survivorship. One example of this mutualistic relationship is bees and flowers, the bees gather the pollen and as they travel from flower to flower they pollinate them. A flower gets its pollen passed from one individual to another. In turn the flower provides a food reward in the form of nectar, or pollen as a solid food source. A parasite is an organism that may not be closely related to the host organism, but they co-exist indefinitely until one of the organism dies. The parasitism is characterized by one organism (usually the smaller organism) benefits from the host organism that is harmed by the relationship. An example of this parasitic relationship is the hookworm which lives in the intestine of its host, usually a cat or dog. http://www.aber.ac.uk/~mpgwww/Edu/EduIndex.html Begon, M., J.L. Harper and C.R. Townsend. 1996. Ecology: individuals, populations, and communities, Third Edition. Blackwell Science Ltd., Cambridge, Massachusetts, USA. Mike Tomlinson
Enhancement:
Parasitism is a symbiotic relationship where one organism is dependent on the other, but harms its host in the process. It is similar to amensalism, but with amensalism the visitor organism is not necessarily dependent on the host. In contrast, in a true mutualistic sybiotic relationship, both species are dependent on each other, and benefit each other.(The American Heritage® Science Dictionary, http://dictionary.reference.com/browse/Symbiosis)
Jake
Mutualism / Lichen; Lichen – the symbiotic relationship formed by mutualistic association between a fungus and a photosynthetic algae or cyanobacterium (Campbell & Reece, Biology 7th ed. Glossary). Mutualism – a symbiotic relationship in which both participants benefit (Campbell & Reece, Biology 7th ed. Glossary). Lichens are a symbiotic association of millions of photosynthetic microorganisms held in a mass of fungal hyphae, meaning the fungal component is usually an ascomycete and the photosynthetic partner is usually a unicellular or filamentous green algae or cyanobacteria (Campbell & Reece, Biology 7th ed. Pg 621). These structures are involved in the transfer of carbohydrates and nitrogen compounds from the photobiont (the photosynthetic compound of the lichen) to the fungus (Raven, Biology of Plants, pg 290). In english terms, this means that lichen need mutualism with a fungus and a photosynthetic microorganism to live and survive. Stephanie Lauer
Mutualism/Symbiosis (Dennis Murengi) Mutualism: The living together of two or more organisms in an association that is mutually advantageous. (Biology of Plants 7th Edition G-15) Symbiosis: The living together of in close association of two or more dissimilar organisms; includes parasitism (in which the association is harmful to one of the organisms) - Biology of Plants 7th Edition G-23) Both mutualism and symbiosis are similar in that they both involve an association between two or more organisms. However the two relationships differ in that mutualism is a type of symbiosis in which both or all of the organisms involved benefit from the relationship. (www.biology-online.org) http://www.biology-online.org/dictionary/Mutualism Symbiosis on the other, hand also includes parasitism, which is a one-sided relationship whereby one of the symbionts (the parasite) benefits at the expense of the other (the host). (www.eden.rutgers.edu) http://www.eden.rutgers.edu/~tavisa/Symbiosis.html
Mycelium/Mycorrhiza Mycelium: The mass of fine branching tubes (known as hyphae) that forms the main growing structure of a fungus. Visible structures like mushrooms are reproductive structures produced by the mycelium. www.thefreedictionary.com/mycelium Mycorrhiza: The symbiotic association of the mycelium of a fungus with the roots of certain plants, such as conifers, beeches, or orchids. www.answers.com/topic/mycorrhiza Mycorrhiza is the relationship between mycelium and the roots of other plants. (Matti Harper)
Mycorrhizae/Lichen
Mycorrhizae:
Mycorrizhae are a mutually beneficial relationship between the roots of vascular plants and fungi. Nearly all higher plants exhibit this relationship and when are grown without fungi they experience malnutrition and often die. In this relationship the plants benefit through increased uptake of water and nutrients and protection from pathogens while the fungus benefits through transfer of carbohydrates from the plant. (Jennings, D.H. and Lysik G., 1996) and (Freeman 2004)
Lichen:
Lichen are a relationship between a fungus and a green algae or a cyanobacteria. In this relationship the fungus is called the mycobiont and the algae or cyanobacteria is called the photobiont. The fungus and the photobiont are connected by hyphae from the fungus that penetrate the cells of the photobiont, through which the fungus obtains carbohydrates and nitrogen. The photobiont also benefits from this relationship because it is provided with and ideal place to grow. (Freeman 2004)
Lichen and Mycorrhizae are similar in that they are both examples of mutualistic relationships. A mutualistic relationship is when two or more organisms live together in a situation through which they both benefit. They are also similar in that the fungi in both relationships obtains carbohydrates from the other organism. A difference between lichen and mycorrhizae is that mycorrhize are an associaton between a fungus and a plant while a lichen is a relationship between an algae or a cyanobacteria and a fungus.
Katherine Loewen
Mycorrhiza/Parasite (AarenS)
A parasite is an organism that lives in or on a member of a different species and derives nutrients from it, this relationship is beneficial to the parasite and harmful to the host. (Biology of Plants, 7th edition).
A mycorrhiza is a fungus which attaches to the roots of a host of a different species (a tree in this case) and enters a relationship with the host that is beneficial to both the host and the fungi. In this relationship the host provides nutrients in the form of sugars to the fungi, and the fungus provides an increase of surface area which the tree uses to absorb a greater amount of water and nutrients.
Parasites and mycorrhiza are similar in that they both have evolved to be dependant on another organism in order to live and reproduce. Parasites and mycorrhizae differ because while the parasitic relationship benefits only the parasite and harms the host, the mycorrhiza has entered a relationship which is beneficial to both organisms.
Mycorrhiza/Root Hairs
Mycorrhiza: A symbiotic association between certain fungi and plant roots; characteristic of most vascular plants. These symbioses are characterized by bi-directional movement of nutrients where carbon flows to the fungus and inorganic nutrients move to the plant, thereby providing a critical linkage between the plant root and soil. In infertile soils, nutrients taken up by the mycorrhizal fungi can lead to improved plant growth and reproduction. As a result, mycorrhizal plants are often more competitive and better able to tolerate environmental stresses than are nonmycorrhizal plants.
Root Hairs: A tiny extension of a root epidermal cell, growing just behind the root tip and increasing the surface area for absorption of water and minerals. It is a delicate structure, which survives for a few days only and does not develop into a root. Root hair cells are found just behind the root tip where they are continually being formed. They grow out into the soil for a few millimetres to produce the root hair. Each root hair is made of a single cell. At the root tip mitosis cell division is very active making new cells for growth to replace the root hair cells that die.
Mycorrhiza/Zygomycete Mycorrhiza: A symbiotic association between certain fungi and plant roots; characteristic of most vascular plants. These symbioses are characterized by bi-directional movement of nutrients where carbon flows to the fungus and inorganic nutrients move to the plant, thereby providing a critical linkage between the plant root and soil. In infertile soils, nutrients taken up by the mycorrhizal fungi can lead to improved plant growth and reproduction. As a result, mycorrhizal plants are often more competitive and better able to tolerate environmental stresses than are nonmycorrhizal plants. Zygomycete: a fungus (i.e. bread mold) that lives on organic matter or as a parasite. The most common members of the Zygomycota are the fast growing members of the Mucorales. They function as decomposers in soil and dung, thereby playing a significant role in the carbon cycle.
Parasite/Pathogen
Parasite: A parasite is an organism that lives in or on another organism, its host. A parasite is dependent on the host for nourishments and life functions. A parasite usually causes some harm to the host. Two examples of plant species that parasitize on other plants include, mistletoe and parasitic dodder. (MSN Encarta: Online )
Pathogen: A pathogen is a living microorganism that uses another organism, a host, for nourishment, causing illness and disease. Pathogens include various types of bacteria and fungus. (Biology Online org) A parasite and a pathogen share a similar relationship with another organism, or host, using it to obtain nourishment.
The difference between a pathogen and a parasite is the outcome they cause on the host. A parasite causes harm compared to the pathogen that can infect, causing disease or illness.
References: Biology Online Org. Website found: http://www.biology-online.org/dictionary/Pathogens
MSN Encarta:Online. Website found:http://encarta.msn.com/encyclopedia
- Nikki Heim.
Parasite vs. Saprophyte Parasite is an organism that lives on or in the host of a different species. This relationship is harmful to the host because the parasite derives some or all of its nutreints from the host. Saprophyte is an organism that lives on dead organic matter. Both parasites and saprophytes may harm their host. A saprophyte may decay the heartwood of a tree which would weaken the strength of the tree. A parasite may not decay the tree but it will weaken the tree by consuming the nutrient that the tree is manufacturing.
Jessi.E.W
Parasite/Symbiosis
Parasite: An organism that lives on or in a different kind of organism, the host from which it gets some or all of its nourishment. Parasites are generally harmful to their hosts (Raven Glossary. p.16), although the damage they do ranges widely from minor inconvenience to debilitating or fatal disease.
Symbiosis: Symbiosis is a close ecological relationship between the individuals of two or more different species. Sometimes a symbiotic relationship benefits both species, sometimes one species benefits at the other's expense, and in other cases neither species benefits. This relationship includes parasitism and mutualism (advantageous to both) (Raven Glossary. p.23). Parasite is harmful to the host, whereas symbiosis generally benefits the host. Rarely, the symbiosis relationship can be harmful to the host. Tamiki N
http://www.thefreedictionary.com/parasite, http://www.cals.ncsu.edu/course/ent591k/symbiosis.html
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