Exploring Fungal Structures and Functions for Enhanced Productivity

1. Reproductive structure.The mushroom produces tiny cells called spores. Hyphae. The mushroom and its subterranean mycelium are a continuous network of hyphae. Spore-producing structures 20 m Mycelium Body Structure • The morphology of multicellular fungi • Enhances ability to absorb nutrients • Chitin Hyphae Mycellum Figure 31.2

2. Hyphal Structure • Most are multicellular • Cells divided by septa • Some have no cross wall- Coenocytic Figure 31.3

3. Hyphal Structure haustoria Figure 31.4a, b

4. Nematode Hyphae 25 m (a) Hyphae adapted for trapping and killing prey Hyphal Structure Figure 31.4a, b

5. Mycorrhizae • Are mutually beneficial relationships between fungi and plant roots • Mycorrhizae “fungus roots” • Delivers minerals and receives organic nutrients • Ectomycorrhizal fungi: Grow in extracellular spaces of roots • Endomycorrhizal fungi: Hyphae go through cell wall to plasmamembrane

6. Mycorrhizae Increase plant productivity Fungus-Plant Symbiosis RESULTS RESULTS Figure 31.21

7. Malted barley

11. Saccharomyces cerevisiae

12. Brewer's yeast tolerate up to about 5% alcohol. Beyond this alcohol level the yeast cannot continue fermentation. Wine yeast on the other hand tolerates up to about 12% alcohol. The level of alcohol tolerance by yeast varies from 5% to about 21% depending on yeast strain. • Part 1 Aerobic (Oxygen is present) This is the initial rapid process where the yeast is doubling its colony size every 4 hours. (Usually 24-48 hours) • Part 2 Anaerobic. (No oxygen present) Slower activity and the yeast focuses on converting sugar to alcohol rather that increasing the number of yeast cells. (This process can take from days to weeks depending on the yeast and the recipe)

13. The overall process of fermentation is to convert glucose sugar (C6H12O6) to alcohol (CH3CH2OH) and carbon dioxide gas (CO2). The reactions within the yeast to make this happen are very complex but the overall process is as follows: • C6H12O6    ====>   2(CH3CH2OH)      +        2(CO2)    Sugar      ====>       Alcohol             +   Carbon dioxide gas (Glucose)               (Ethyl alcohol) •  Note: The sugars used can be a range of fermentable sugars. These sugars are converted by enzymes to glucose which is then convered to alcohol and CO2

14. Diploid phase follows karyogamy • Short-lived (2n) spore-producing structures and (1n) spores Ascocarp Basidiocarp Sporangia

15. Concept 31.3: Fungi descended from an aquatic, single-celled, flagellated protist • Fungi and Animalia as sister kingdoms • Fungi early colonizers of land, probably as symbionts with plants.

16. Concept 31.4: Fungi radiated into a diverse set of lineages

17. Chytrids • Found in freshwater and terrestrial habitats • They can be saprobic or parasitic • Zoospores: unique with flagellated spores Hyphae Figure 31.10

18. Zygomycetes • Fast growing bread and fruit molds • Can also be parasitic or symbiotic relationship

19. Zygomycetes Key Haploid (n) Heterokaryotic (n + n) Diploid (2n) PLASMOGAMY Rhizopus growing on bread Mating type (+) Mating type (–) 100 µm SEXUAL REPRODUCTION Dispersal and germination Zygosporangium (heterokaryotic) Sporangia KARYOGAMY Sporangium Diploid nuclei ASEXUAL REPRODUCTION Zygospore MEIOSIS Dispersal and germination Figure 31.13 Mycelium 50 µm

20. Zygomycetes • Pilobolus “aim” their sporangia toward the light http://www.youtube.com/watch?v=9CRNmde0WUc&feature=related http://www.youtube.com/watch?v=TrKJAojmB1Y Figure 31.14

21. Zygomycetes • Pilobolus “aim” their sporangia toward the light

22. Glomeromycetes • arbuscular mycorrhizae • See Figure 31.15 http://www.agro-genesis.com/pics/cropscience_rhizogold1.jpg

23. Ascomycetes

24. Glomeromycetes • Spores produced in a saclike asci “sac fungi” • Asci are within the ascocarp

25. Basidiomycetes • Include mushrooms and shelf fungi • Clublike structure called a basidium

26. Mushrooms are examples of basidiocarps Figure 31.20

28. Concept 31.5: Fungi have a powerful impact on ecosystems and human welfare

29. Decomposers • Essential recycling between the living and nonliving world

30. Fungus-Animal Symbiosis • Helping break down plant material Figure 31.22

31. (a) A fruticose (shrub-like) lichen Figure 31.23a–c (b) A foliose (leaf-like) lichen (c) Crustose (crust-like) lichens Lichens • Symbiotic association of photosynthetic microorganisms held in fungal hyphae

32. Ascocarp of fungus Soredia Fungal hyphae Algal layer Algal cell Fungal hyphae 10 m Figure 31.24 Lichens • The fungal component • Is most often an Ascomycete • Algae or cyanobacteria • Occupy an inner layer below the lichen surface

33. (b) Tar spot fungus on maple leaves (a) Corn smut on corn (c) Ergots on rye Figure 31.25a–c Pathogens • About 30% of known fungal species • Are parasites, mostly on or in plants

34. Practical Uses of Fungi • Make cheeses, alcoholic beverages, and bread • Genetic research on fungi is leading to applications in biotechnology • Antibiotics produced by fungi treat bacterial infections

35. Red algae ANCESTRAL ALGA Chlorophytes Viridiplantae Charophytes Streptophyta Plantae Embryophytes Charophytes

36. Overview: The Greening of Earth • 3 billion years terrestrial surface was lifeless • Now roughly 290,000 living plant species