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1、植物微生物学第四讲Unlike chromistan fungi - most have no motile stages so best adapted to landlPhylum Chytridiomycota（壶菌门）壶菌门）exception - do have flagellae - 1 posterior whiplash,lPhylum Zygomycota（接合菌门）接合菌门）most have coenocytic hyphae (ie no septae)lPhylum- Dikaryomycota（双核菌门）双核菌门）septate hyphae. Largest an
2、d most important group.By far the largest group of fungi:lover 100,000 sp knownlprobably well over 1,000,000 exist!lmany capable of digesting very complex substances (cellulose, lignin， chitin ) - due to extracellular enzymes（胞外酶）胞外酶）lhyphae （菌丝）菌丝） can penetrate into solid masses e.g wood and decom
3、pose it rapidlylproduce vast numbers of spores so capable of spreading rapidly.（产孢繁殖）产孢繁殖） mostly live in water or soil - decomposerssingle cell or hyphae, 营养体为简单细胞或营养体为简单细胞或菌丝菌丝sometimes develop rhizoids（根状体）根状体）often parasiticlSynchytrium（集壶菌属）集壶菌属） causes wart disease of potatoes（马铃薯癌肿病）马铃薯癌肿病）Po
4、tato wart diseaseSynchytrium endobioticum severe effect on yield resistant varieties available - but new virulent strains of fungus arising warts contain sporangia which release zoospores - infect new potatoes - cause rapid cell division = wartlwide, thin-walled multinucleate coenocytic hyphae粗大的薄壁多
5、核无隔菌丝粗大的薄壁多核无隔菌丝llimited ability to digest complex substrateslsexual spore = a thick walled zygosporangium（接合孢子）接合孢子） - germinates by meiosis to form new hyphae.Phylum Zygomycotalclass Zygomycetes 接合菌纲Mucorales毛霉目 腐生 - saprobic (eg bread moulds)lcommon saprophytes - but limited ability to degrade co
6、mplex compounds compared to Dikaryomycota lLife cycle - see Rhizopus stolonifer (Fig 3.5)lclass Trichomycetes 毛菌纲- parasites of arthropods 节肢动物的寄生物Eumycotan FungiBread Mould - Rhizopus stoloniferLife cycle of Rhizopus stoloniferaMucor - Life CycleSexual stages - teleomorphAsexual stages - anamorphZy
7、gospore of Rhizopus (diploid - will go through meiosis)Sporangium in RhizopussporangiophoreSporangium containing many sporangiospores (asexual)孢子囊内含许多孢子囊内含许多孢囊孢子（无性的）孢囊孢子（无性的）Anamorphs in ZygomyceteslChromistan FungilEumycotan Fungi.1. Chytridiomycota2. Zygomycota3. DikaryomycotaAscomycotinaBasidiom
8、ycotinaphylasub-phylaCompared to Zygomycota :-1. have thinner hyphae菌丝细- thicker walls 壁厚 divided into compartments by 有隔 septae which contain pores.隔板有孔2. This makes them tougher and much more able to thrive in drier situations更耐干旱3. More capable of utilizing complex substances - e.g cellulose., li
9、gnin, keratin, chitin.4. Many important pathogens of plantsl5. Very important in mycorrhizal菌根 associations l6. Many species have developed an association with algae to form lichens地衣. l7. Hyphae can fuse and exchange nuclei and form heterokaryons异核体, particularly dikaryons 二核体- necessary stage to s
10、exual reproduction.Dikaryon = cells have 2 haploid nuclei of different origins in a stable state - continued on each cell divisionrestricted dikaryophase (only in special fruiting bodies - ascoma)二核阶段不长（与担子菌比）Many cells within the ascoma develop into asci. Nuclear fusion and meiosis occurs to form 4
11、, 8, 16 etc ascospores子囊孢子 inside each ascus子囊.simple septal pores2-layered cell walls双层壁no clamp connections无锁状结构molecular differences from Basidiomycotina (GC content etc.)many pathogenic fungi 许多是病原菌leg humans (ringworm, athletes foot - attack keratin)如足癣lplants - southern corn blight, powdery mi
12、ldews玉米小斑病和白粉病rots and moulds of wood and cotton etc木材和棉花霉烂producers of mycotoxins (eg aflatoxin)产毒素如黄曲霉beneficial decomposers of material in soils 土中的分解者insect and nematode predators and parasites昆虫和线虫的捕食者和寄生物useful in food (yeast, cheeses) or antibiotic prep. (penicillin, cyclosporine)用于食品（酵母和奶酪）或
13、生产抗生素important in molecular and classical genetics分子和经典遗传学的模式生物。Taphrina deformans - peach leaf curlClaviceps purpurea - ergot of Ryecaused outbreaks of St Anthonys Fire in Middle Ages. Source of LSDHighly prized edible Morels 子囊菌纲filamentous species丝状菌 酵母纲 unicellular yeast species单细胞的菌 - 半知菌“纲” ca
14、tchall group for species without sexual stageslmost Lichen fungi are Ascomycetesl大多数地衣真菌是子囊菌纲lAnamorph = asexual stages - mitosis - usually haploidl无性阶段，有丝分裂，通常是单倍体lTeleomorph = sexual stages - involves dikaryons, diploidy and meiosisl有性阶段，涉及二核阶段、二倍体阶段和减数分裂三个阶段Teleomorph begins when hyphae anastomos
15、e (= fuse together), become dikaryotic and aggregate into compact masses (ascoma). 有性阶段始于菌丝融合时，变成二核体，聚集成紧密的一团。lapothecia - open cupsl子囊盘，开放的杯状物lperithecia + pseudothecia - narrow opening flasksl子囊壳+假囊壳- 小口烧瓶状lcleistothecia - closed spheres or flasks.l闭囊壳 - 封闭的瓶状物或烧瓶状物4. cleistothecium2. perithecium3
16、. pseudotheciumTypes of ascoma子囊果的类型1. ApotheciumLife cycle of typical AscomyceteLife cycle of typical Ascomycete典型子囊菌的生活史典型子囊菌的生活史AscomycetesBasidiomycetesclamp connection every time a hyphal cell dividescrozier only found just before ascus formationbitunicate ascus双层壁的子囊unitunicate 单层壁inoperculate
17、无孔口unitunicate 单层壁operculate ascus有孔口原囊态的子囊The 4 main types of asci子囊的子囊的4种主要形态种主要形态lIn Ascomycetes, anamorphs and teleomorphs often develop at different times and places. Each stage is therefore often collected in ignorance of the existence of the otherlNormal classification is based on telomorph s
18、tages, but mycologists have had to classify specimens in which they only find anamorph stages.lThus parallel systems of nomenclature have sprung up - we have teleomorph genera and anamorph genera and mycologists try to draw connections between them where possible. lDNA analyses will make this much e
19、asier in future.l有性和无性阶段在不同时间和地点发生，采集到的标本或是有性或是无性态，正常的分类 是根据有性态，但有些菌只发现了无性态，只好根据无性态分类。因而有两个并行的命名体系。菌物学家试图找到两者间的联系。将来DNA分析技术将使得更容易。lIn some cases it has been possible to connect the anamorph name with the teleomorph name - but in many others this has not yet been done and may never be possible becaus
20、e the organism may have lost the ability to reproduce sexually. lOf 30,000 known Ascomycetes only 5,000 have been connected to their anamorphs - results often messyleg teleomorph genera, Nectria and Gibberella, both have anamorphs which have been classified in the anamorph genus FusariumlMany anamor
21、phs (85%) have no known teleomorph - are termed Deuteromycetes.l有时将有性与无性联系容易，许多情况下难甚至做不到，因为有的菌丧失了有性生殖的能力。30 000种已知的子囊菌只有5 000种与无性态挂上了勾，结果往往是杂乱的，如有性阶段的丛剌壳属和赤霉属的无性阶段都是镰霉属。许多（85%）无性态已知但不知有性态，归到半知菌纲。Recombination during MITOSIS has been observed in many fungi - it may be particularly well developed in D
22、euteromycetes减数分裂时发生重组已在许多真菌中发现，但半知菌尤多。两个不同核的细胞偶尔融合成为双核细胞，通过核融而成体细胞二倍体，有丝分裂时发生交换而分离或丢失染色体成单倍体。Mitotic crossing-over diploid segregantsMitotic divisionsHaploid myceliumDikaryotic cellsSomatic diploids arise through nuclear fusionChromosome loss = haploidizationThe typical anamorph spore in Ascomycete
23、s = conidia produced outside a specialized hyphal cell. 典型无性孢子是分生孢子，外生于特殊菌丝细胞。compare with Zygomycetes which produce sporangiospores inside a sporangium.而接合菌的无性孢子是在孢子囊内产生孢囊孢子。conidia = asexual spores produced in vast numbers by mitotic divisions分生孢子是通过有丝分裂大量产生的无性孢子lconidial features分生孢子特征 - conidiop
24、hores never enclosed分生孢子梗 生 腔孢纲- conidiophores enclosed in a covering.分生孢子梗被封闭lconidial shape and septation importantl孢子形态和分隔数是重要依据lconidiophore details also usedl分生孢子梗的细节也用于分类Coelomycetes have their conidia in a covered structure.Covered either by host cells (acervulus分生孢子盘) or by fungal hyphae in
25、flask shape (pycnidium分生孢子器)acervuluspycnidiumconidium分生孢子器（右）和分生孢子盘（左）conidiumConidia of 孢子孢子Aspergillus sp.Conidiophore孢子梗孢子梗lYeasts are fungi which typically form unicellular cells which divide by budding i.e not filamentous hyphae lMost are Ascomycetous - many form asci, but there are some yeast
26、-like forms in the Zygomycetes and BasidiomyceteslBudding yeast cells considered to be conidialVery important in ecology and for man (brewing and baking)l酵母菌典型情况下形成单细胞的菌体，即没有丝状菌丝，出芽繁殖。大多数是子囊菌，许多形成子囊，但在1. Plant pathogens植物病原菌植物病原菌 over half of important crop pathogens are Ascomycetes.作物病原菌一半是子囊菌lHelm
27、inthosporium maydis - southern corn blight玉米小斑lCryphonectria - chestnut blight - all but eliminated chestnuts in N. America栗疫病lFusarium sp. - cause many wilt diseases, produce mycotoxins镰刀菌，造成萎蔫病，产毒素lBotrytis - several plant diseases - can also produce very expensive sweet wine (ice wine)灰霉菌，引致几种病害，
28、但也生产昂贵的甜葡萄酒。lClaviceps - ergot fungus - causes madness - LSD sourcel麦角菌，造成人类疾病1. Plant pathogens植物病原菌（续）植物病原菌（续）lErysiphe - powdery mildews of plants - haustoria penetrate epidermal cells of host plant 白粉菌-引致植物白粉病-吸器穿透到寄主植物表皮细胞中lOphiostoma - Dutch Elm disease 荷兰榆疫病lVenturia - apple scab disease 苹果疮痂
29、病lTrichoderma - mycoparasite - use in biological control of plant diseasel木霉菌-真菌寄生物-用于植物病害生物防治2. Food and Health 食品与健康（续食品与健康（续）lPenicillium and Aspergillus - used in cheese makingThe enzymes of Penicillium camembertii produce the soft, smooth texture of Camembert and Brie cheeses. Penicillium roque
30、fortii puts that strong flavour in blue cheeses such as Roquefort, Danish Blue, Stilton and Gorgonzola. l青霉菌和曲霉菌青霉菌和曲霉菌-用于奶酪生产。青霉菌的酶产生软光滑的布里白奶酪用于奶酪生产。青霉菌的酶产生软光滑的布里白奶酪lAspergillus oryzae used in the Far East to turn soya protein into soy sauce l米曲霉在远东用于将大豆蛋白转娈成酱油lMorchella (morels) - highly prized mu
31、shroom 高价的蘑菇lTuber (truffles) even more highly prized and priced ! 块菌，价格还要高lTrichophyton and other dermatophytes (keratin- attacking fungi) eg ringworm. athletes foot, jock itch etc 癣菌-足癣等2. Food and Health（食品与健康）食品与健康）lAspergillus flavus (grows on peanuts and many other substrates,producing a mycot
32、oxin called aflatoxin, which contaminates food and causes liver damage - the most potent carcinogen (cancer-inducing) substance known. l黄曲霉（在花生和其它许多基质上生长，产生称为黄曲霉的毒素，污染食品、造成肝病-最烈性的致癌剂）l Fusarium graminearum, growing on feed corn, produces another mycotoxin, zearalenone, which is a steroid, and causes
33、 oestrogenic syndrome - vaginal and rectal prolapse - in young female pigs. l禾谷镰刀菌，在饲料玉米上生长，产生另一种霉菌毒素即玉米烯酮，是一种固醇，造成雌激素综合症，母猪直肠下垂lPenicillium italicum - example of the moulds that spoil food in storage .意大利青霉-储藏的食物变质l3. Rots and decomposition 腐烂与分解腐烂与分解lCellulolytic hyphomycetes cause blue stain and
34、soft rot of wood, discolouration and loss of strength of cotton materials and moulding of almost any damp organic substrate.分解纤维素的丝孢纲真菌木材蓝点和软腐、棉花变色和强度降低、造成任一种潮湿的有机质发霉。lAscomycetes are prime colonizers and decomposers of soft plant debris, playing a vital role in the carbon and nitrogen cycles. Domin
35、ate the soil mycota in most forests. Dead leaves are colonized by aquatic hyphomycetes - tolerant of low temperatures so can grow during the winter and even under ice - make the dead leaves much more palatable and nutritious for the various detritivorous invertebrates which eat them, l子囊菌主要定殖和分解软的植物
36、残体，在碳氮循环中起至关重要的作用。在大多数森林中制约土壤微生物区系。死叶被水中的丝孢菌定殖 耐低温因而可在冬天生长甚至在冰下生长 使死叶成为食粪类无脊椎动物的美食。4. Genetics and Biotechnology 遗传和生物技术上应用lNeurospora - important in classical genetics 脉孢菌-经典遗传学上应用lPenicillium chrysogenum - source of penicillin. 青霉菌-青霉素之源lTolypocladium niveum - source of cyclosporine - the most eff
37、ective and least toxic immunosuppressant 环孢霉素之源-最有效最低毒的免疫遏制剂。lBecoming used as hosts for vectors carrying genes from eukaryotic organisms.- been used to express insulin, human growth factor, human tissue plasminogen activator (used to dissolve blood clots), bovine chymosin (an enzyme used in cheese-
38、making), and amylase and cellulase enzymes .- Have great biotechnological potential .l用作带有真核生物基因的载体的宿主l用来表达胰鸟素、人类生长因子，人类组织血浆酶原活化因子（用来溶解血凝块），牛凝乳酶（用来制奶酪），淀粉酶、纤维素酶等。- asci contain products of one meiosis in an order reflecting segregation of alleles at first and second division.子囊中减数分裂的产物（子囊孢子）反映了第一和第二
39、次分裂后等位基因的分离，Ascomycetes also important in study of mitotic recombination via a parasexual cycle.子囊菌在研究准性生殖中也是重要的。Ascomycetes made major contributions to the study of meiotic recombination 对研究减数分裂重组作出了重大贡献l真菌的分门：壶菌门、接合菌门、双核菌门l接合菌和子囊菌的无性孢子和有性孢子l子囊菌的有性生殖过程（钓状体等）l子囊果、子囊、分生孢子果和分生孢子梗的类型l子囊菌的分亚门，各亚门的特点l重要的子囊菌（4大类）
