|
A gombák parazitái többnyire szintén gombák (mint az aranypenész) vagy gombaszerű organizmusok (pl. a petespórásokhoz tartozó ''Pythium'' nemzetség), de ismertek gombákat fertőző vírusok (mikovírusok) is.<ref name="Le Floch">{{cite journal | vauthors=Le Floch G, Rey P, Benizri E, Benhamou N, Tirilly Y | s2cid=22898373 | title=Impact of auxin-compounds produced by the antagonistic fungus ''Pythium oligandrum'' or the minor pathogen ''Pythium'' group F on plant growth. | journal=Plant Soil | volume=257 | issue=2 | pages=459–470 | date=2003 | doi=10.1023/a:1027330024834}}</ref><ref name="Pearson">{{cite journal | vauthors = Pearson MN, Beever RE, Boine B, Arthur K | title = Mycoviruses of filamentous fungi and their relevance to plant pathology | journal = Molecular Plant Pathology | volume = 10 | issue = 1 | pages = 115–28 | date = January 2009 | pmid = 19161358 | doi = 10.1111/j.1364-3703.2008.00503.x | pmc = 6640375 }}</ref><ref name="Boz">{{cite journal | vauthors = Bozarth RF | title = Mycoviruses: a new dimension in microbiology | journal = Environmental Health Perspectives | volume = 2 | issue = 1 | pages = 23–39 | date = October 1972 | pmid = 4628853 | pmc = 1474899 | doi = 10.1289/ehp.720223 }}</ref>
== MycotoxinsGombatoxinok ==
[[File:Ergotamine3.png|thumb|right|alt=(6aR,9R)-N-((2R,5S,10aS,10bS)-5-benzyl-10b-hydroxy-2-methyl-3,6-dioxooctahydro-2H-oxazolo[3,2-a] pyrrolo[2,1-c]pyrazin-2-yl)-7-methyl-4,6,6a,7,8,9-hexahydroindolo[4,3-fg] quinoline-9-carboxamide|[[Ergotamine]], a major mycotoxin produced by ''[[Claviceps]]'' species, which if ingested can cause [[gangrene]], convulsions, and [[hallucination]]s]]
Számos gomba termel bioaktív anyagokat, amelyek mérgezőek is lehetnek az állatok bagy a növények számára (mikotoxinok). Különleges jelentőségük van a mérgező erdei és mezei gombáknak (közülük is a leghírhedtebb a gyilkos galóca), az élelmiszer megromlását okozó penészek toxinjainak, valamint az anyarozs pékárukat is megmérgező, ergoizmust okozó toxikus alkaloidái.<ref name=Schardl2007/> Az Aspergillus penészek gabonán és dióféléken növő egyes tagjai rákkeltő aflatoxint termelnek. Egyéb gazdasági, egészségügyi szempontból jelentős, penészgombák, fuzáriumok átal termelt méreg még az okratoxin, a patulin, a trichotecén vagy a fumonison.<ref name="Janik et al. 2020"/>
Many fungi produce [[biological activity|biologically active]] compounds, several of which are [[toxin|toxic]] to animals or plants and are therefore called [[mycotoxins]]. Of particular relevance to humans are mycotoxins produced by molds causing food spoilage, and poisonous mushrooms (see above). Particularly infamous are the lethal [[amatoxin]]s in some ''[[Amanita]]'' mushrooms, and [[Ergotamine|ergot alkaloids]], which have a long history of causing serious epidemics of [[ergotism]] (St Anthony's Fire) in people consuming [[rye]] or related [[cereal]]s contaminated with [[sclerotia]] of the ergot fungus, ''[[Claviceps purpurea]]''.<ref name=Schardl2007/> Other notable mycotoxins include the [[aflatoxin]]s, which are insidious [[Hepatotoxicity|liver toxins]] and highly [[carcinogenic]] metabolites produced by certain ''[[Aspergillus]]'' species often growing in or on grains and nuts consumed by humans, [[ochratoxin]]s, [[patulin]], and [[trichothecene]]s (e.g., [[T-2 mycotoxin]]) and [[fumonisin]]s, which have significant impact on human food supplies or animal [[livestock]].<ref name="Janik et al. 2020"/>
A mikotoxinok általában másodlagos metabolitok, amelyeket a gombák arra a célra termelnek, hogy visszaszorítsák a környezetükben található többi gomba vagy baktérium növekedését (ezeket a gyógyászatban is felhasználják), vagy megakadályozzák az állatok általi elfogyasztásukat.<ref name=Demain2000/><ref name=Rohlfs2007/>
Mycotoxins are secondary metabolites (or [[natural product]]s), and research has established the existence of biochemical pathways solely for the purpose of producing mycotoxins and other natural products in fungi.<ref name=Keller2005/> Mycotoxins may provide [[Fitness (biology)|fitness]] benefits in terms of physiological adaptation, competition with other microbes and fungi, and protection from consumption ([[fungivore|fungivory]]).<ref name=Demain2000/><ref name=Rohlfs2007/> Many fungal secondary metabolites (or derivatives) are used medically, as described under Human Use below.
==Felhasználásuk==
==Pathogenic mechanisms==
[[File:S cerevisiae under DIC microscopy.jpg|thumb|upright|right |alt=Microscopic view of five spherical structures; one of the spheres is considerably smaller than the rest and attached to one of the larger spheres|''[[Saccharomyces cerevisiae]]'' cells shown with [[Differential interference contrast microscopy|DIC microscopy]]]] ▼''[[Ustilago maydis]]'' is a pathogenic plant fungus that causes smut disease in maize and [[teosinte]]. Plants have evolved efficient defense systems against pathogenic microbes such as ''U. maydis''. A rapid defense reaction after pathogen attack is the [[oxidative burst]] where the plant produces [[reactive oxygen species]] at the site of the attempted invasion. ''U. maydis'' can respond to the oxidative burst with an oxidative stress response, regulated by the gene ''[[YAP1]]''. The response protects ''U. maydis'' from the host defense, and is necessary for the pathogen's virulence.<ref name=Molina2007/> Furthermore, ''U. maydis'' has a well-established recombinational [[DNA repair]] system which acts during mitosis and meiosis.<ref name=Kojic2006/> The system may assist the pathogen in surviving DNA damage arising from the host plant's oxidative defensive response to infection.<ref name=Michod2008/>
''[[Cryptococcus neoformans]]'' is an encapsulated yeast that can live in both plants and animals. ''C.{{nbsp}}neoformans'' usually infects the lungs, where it is phagocytosed by [[alveolar macrophage]]s.<ref name=Fan2005/> Some ''C.{{nbsp}}neoformans'' can survive [[intracellular|inside]] macrophages, which appears to be the basis for [[latency period|latency]], disseminated disease, and resistance to antifungal agents. One mechanism by which ''C.{{nbsp}}neoformans'' survives the hostile macrophage environment is by up-regulating the expression of genes involved in the oxidative stress response.<ref name=Fan2005 /> Another mechanism involves [[meiosis]]. The majority of ''C.{{nbsp}}neoformans'' are mating "type a". Filaments of mating "type a" ordinarily have haploid nuclei, but they can become diploid (perhaps by endoduplication or by stimulated nuclear fusion) to form [[blastospore]]s. The diploid nuclei of blastospores can undergo meiosis, including recombination, to form haploid basidiospores that can be dispersed.<ref name=Lin2005/> This process is referred to as monokaryotic fruiting. This process requires a gene called ''[[DMC1]]'', which is a conserved homologue of genes ''[[recA]]'' in bacteria and ''[[RAD51]]'' in eukaryotes, that mediates homologous chromosome pairing during meiosis and repair of DNA double-strand breaks. Thus, ''C.{{nbsp}}neoformans'' can undergo a meiosis, monokaryotic fruiting, that promotes recombinational repair in the oxidative, DNA damaging environment of the host macrophage, and the repair capability may contribute to its virulence.<ref name=Michod2008/><ref name=Lin2005/>
==Human use==
▲[[File:S cerevisiae under DIC microscopy.jpg|thumb|upright|right|alt=Microscopic view of five spherical structures; one of the spheres is considerably smaller than the rest and attached to one of the larger spheres|''[[Saccharomyces cerevisiae]]'' cells shown with [[Differential interference contrast microscopy|DIC microscopy]]]]
The human use of fungi for food preparation or preservation and other purposes is extensive and has a long history. [[Mushroom farming]] and [[mushroom gathering]] are large industries in many countries. The study of the historical uses and sociological impact of fungi is known as [[ethnomycology]]. Because of the capacity of this group to produce an enormous range of [[natural products]] with [[antimicrobial]] or other biological activities, many species have long been used or are being developed for industrial [[production of antibiotics]], vitamins, and [[Taxol#Production|anti-cancer]] and [[Lovastatin|cholesterol-lowering]] drugs. More recently, methods have been developed for [[genetic engineering]] of fungi,<ref name=Finsham1989/> enabling [[metabolic engineering]] of fungal species. For example, genetic modification of yeast species<ref name=Hawkins2008/>—which are easy to grow at fast rates in large fermentation vessels—has opened up ways of [[pharmaceutical]] production that are potentially more efficient than production by the original source organisms.<ref name=Huang2008/>
|
