31 fungi text

[object Object],[object Object],[object Object],[object Object],Figure 31.1

[object Object],[object Object],[object Object]

Nutrition and Fungal Lifestyles ,[object Object],[object Object],[object Object],[object Object]

[object Object],[object Object],[object Object],[object Object]

Body Structure ,[object Object],[object Object],Hyphae. The mushroom and its subterranean mycelium are a continuous network of hyphae. Reproductive structure. The mushroom produces tiny cells called spores. Spore-producing structures 20  m Mycelium Figure 31.2

[object Object],[object Object],[object Object],[object Object],Nuclei Cell wall Septum Pore (a) Septate hypha (b) Coenocytic hypha Cell wall Nuclei Figure 31.3a, b

[object Object],[object Object],Nematode Hyphae 25  m (a) Hyphae adapted for trapping and killing prey (b) Haustoria Fungal hypha Plant cell wall Haustorium Plant cell plasma membrane Plant cell Figure 31.4a, b

[object Object],[object Object]

[object Object],Key Haploid ( n ) Heterokaryotic (unfused nuclei from different parents) Diploid (2 n ) PLASMOGAMY (fusion of cytoplasm) Heterokaryotic stage KARYOGAMY (fusion of nuclei) SEXUAL REPRODUCTION Spore-producing structures Spores ASEXUAL REPRODUCTION Zygote Mycelium GERMINATION GERMINATION MEIOSIS Spore-producing structures Spores Figure 31.5

Sexual Reproduction ,[object Object],[object Object],[object Object],[object Object],[object Object]

Asexual Reproduction ,[object Object]

[object Object],[object Object],2.5  m Figure 31.6

[object Object],[object Object],[object Object],10  m Parent cell Bud Figure 31.7

The Origin of Fungi ,[object Object],[object Object],[object Object],[object Object]

[object Object],[object Object],Figure 31.8 50  m

The Move to Land ,[object Object],[object Object]

[object Object],[object Object],[object Object],[object Object],[object Object]

[object Object],Chytrids Zygote fungi Arbuscular mycorrhizal fungi Sac fungi Club fungi Chytridiomycota Zygomycota Glomeromycota Ascomycota Basidiomycota Figure 31.9

Chytrids ,[object Object],[object Object],[object Object]

[object Object],[object Object],25  m 4  m Hyphae Flagellum Figure 31.10

[object Object],[object Object],[object Object],[object Object],Some chytrids Zygomycetes and other chytrids Glomeromycetes, ascomycetes, and basidiomycetes Common ancestor Key Loss of flagella Figure 31.11

Zygomycetes ,[object Object],[object Object],[object Object],[object Object]

[object Object],[object Object],Figure 31.12 Rhizopus growing on bread ASEXUAL REPRODUCTION Mycelium Dispersal and germination MEIOSIS KARYOGAMY PLASMOGAMY Key Haploid ( n ) Heterokaryotic ( n + n ) Diploid Sporangium Diploid nuclei Zygosporangium (heterokaryotic) 100  m Young zygosporangium (heterokaryotic) SEXUAL REPRODUCTION Dispersal and germination Mating type (+) Mating type (  ) Gametangia with haploid nuclei 50  m Sporangia Mycelia have various mating types (here designated +, with red nuclei, and  , with blue nuclei). 1 Neighboring mycelia of different mating types form hyphal extensions called gametangia, each walled off around several haploid nuclei by a septum. 2 A heterokaryotic zygosporangium forms, containing multiple haploid nuclei from the two parents. 3 The sporangium disperses genetically diverse, haploid spores. 7 4 This cell develops a rough, thick-walled coating that can resist dry environments and other harsh conditions for months. 5 When conditions are favourable, karyogamy occurs, followed by meiosis. 6 The zygosporangium then breaks dormancy, germinating into a short sporangium. The spores germinate and grow into new mycelia. 8 9 Mycelia can also reproduce asexually by forming sporangia that produce genetically identical haploid spores.

[object Object],[object Object],0.5 mm Figure 31.13

Microsporidia ,[object Object],[object Object],[object Object],10  m Host cell nucleus Developing microsporidian Spore Figure 31.14

Glomeromycetes ,[object Object],[object Object],[object Object]

[object Object],[object Object],2.5  m Figure 31.15

Ascomycetes ,[object Object],[object Object],[object Object]

[object Object],[object Object],(a) The cup-shaped ascocarps (fruiting bodies) of Aleuria aurantia give this species its common name: orange peel fungus. (b) The edible ascocarp of Morchella esculenta, the succulent morel, is often found under trees in orchards. (c) Tuber melanosporum is a truffle, an ascocarp that grows underground and emits strong odors. These ascocarps have been dug up and the middle one sliced open. (d) Neurospora crassa feeds as a mold on bread and other food (SEM). 10  m Figure 31.16a–d

[object Object],Figure 31.17 Dispersal ASEXUAL REPRODUCTION Germination Mycelium Conidiophore Germination Dispersal Mycelia Asci Eight ascospores Ascocarp Four haploid nuclei MEIOSIS KARYOGAMY PLASMOGAMY SEXUAL REPRODUCTION Diploid nucleus (zygote) Ascogonium Ascus (dikaryotic) Dikaryotic hyphae Mating type (  ) Conidia; mating type (  ) Key Haploid ( n ) Dikaryotic ( n  n ) Diploid (2 n ) Ascomycete mycelia can also reproduce asexually by producing haploid conidia. 7 Neurospora can reproduce sexually by producing specialized hyphae. Conidia of the opposite mating type fuse to these hyphae. 1 A dikaryotic ascus develops. 2 Karyogamy occurs within the ascus, producing a diploid nucleus. 3 The diploid nucleus divides by meiosis, yielding four haploid nuclei. 4 The developing asci are contained in an ascocarp. The ascospores are discharged forcibly from the asci through an opening in the ascocarp. Germinating ascospores give rise to new mycelia. 6 5 Each haploid nucleus divides once by mitosis, yielding eight nuclei. Cell walls develop around the nuclei, forming ascospores (LM).

Basidiomycetes ,[object Object],[object Object],[object Object]

[object Object],(a) Fly agaric ( Amanita muscaria ), a common species in conifer forests in the northern hemisphere (b) Maiden veil fungus ( Dictyphora ), a fungus with an odor like rotting meat (c) Shelf fungi, important decomposers of wood (d) Puffballs emitting spores Figure 31.18a–d

[object Object],[object Object],Figure 31.19

[object Object],Figure 31.20 PLASMOGAMY Dikaryotic mycelium Basidiocarp (dikaryotic) KARYOGAMY Key MEIOSIS Gills lined with basidia SEXUAL REPRODUCTION Mating type (  ) Mating type (  ) Haploid mycelia Dispersal and germination Basidiospores Basidium with four appendages Basidium containing four haploid nuclei Basidia (dikaryotic) Diploid nuclei Basidiospore 1  m Basidium Haploid ( n ) Dikaryotic ( n  n ) Diploid (2 n ) Each diploid nucleus yields four haploid nuclei. Each basidium grows four appendages, and one haploid nucleus enters each appendage and develops into a basidiospore (SEM). 6 Two haploid mycelia of different mating types undergo plasmogamy. 1 A dikaryotic mycelium forms, growing faster then, and ultimately crowding out, the haploid parental mycelia. 2 3 Environmental cues such as rain or temperature changes induce the dikaryotic mycelium to form compact masses that develop into basidiocarps (mushrooms, in this case). The basidiocarp gills are lined with terminal dikaryotic cells called basidia. 4 Karyogamy in the basidia produces diploid nuclei, which then undergo meiosis. 5 When mature, the basidiospores are ejected, fall from the cap, and are dispersed by the wind. 7 In a suitable environment, the basidiospores germinate and grow into short-lived haploid mycelia. 8

Decomposers ,[object Object],[object Object]

Symbionts ,[object Object],[object Object]

Mycorrhizae ,[object Object],[object Object],[object Object],RESULTS RESULTS Researchers grew soybean plants in soil treated with fungicide (poison that kills fungi) to prevent the formation of mycorrhizae in the experimental group. A control group was exposed to fungi that formed mycorrhizae in the soybean plants’ roots. EXPERIMENT The soybean plant on the left is typical of the experimental group. Its stunted growth is probably due to a phosphorus deficiency. The taller, healthier plant on the right is typical of the control group and has mycorrhizae. CONCLUSION These results indicate that the presence of mycorrhizae benefits a soybean plant and support the hypothesis that mycorrhizae enhance the plant’s ability to take up phosphate and other needed minerals. Figure 31.21

Fungus-Animal Symbiosis ,[object Object],[object Object]

[object Object],[object Object],Figure 31.22

Lichens ,[object Object],[object Object],(a) A fruticose (shrub-like) lichen (b) A foliose (leaf-like) lichen (c) Crustose (crust-like) lichens Figure 31.23a–c

[object Object],[object Object],[object Object],[object Object],Ascocarp of fungus Fungal hyphae Algal layer Soredia Algal cell Fungal hyphae 10  m Figure 31.24

Pathogens ,[object Object],[object Object],(a) Corn smut on corn (b) Tar spot fungus on maple leaves (c) Ergots on rye Figure 31.25a–c

Practical Uses of Fungi ,[object Object],[object Object]

[object Object],[object Object],Staphylococcus Penicillium Zone of inhibited growth Figure 31.26

31 fungi text

Empfohlen

Empfohlen

Weitere ähnliche Inhalte

Was ist angesagt?

Was ist angesagt? (20)

Andere mochten auch

Andere mochten auch (20)

Ähnlich wie 31 fungi text

Ähnlich wie 31 fungi text (20)

Mehr von Andrew McCaskill

Mehr von Andrew McCaskill (13)

31 fungi text