FUNGI

YOU MUST KNOW…• THE CHARACTERISTICS OF

FUNGI• IMPORTANT ECOLOGICAL ROLES

OF FUNGI IN MYCORRHIZAL ASSOCIATIONS, AND AS DECOMPOSERS AND PARASITIC PLANT PATHOGENS

WHAT IS MYCORRHIZAL?

• A symbiotic (generally mutualistic, but occasionally weakly pathogenic) association between a fungus and the roots of a vascular plant.

CONCEPT 31.1• FUNGI ARE HETEROTROPHS

THAT FEED BY ABSORPTION

• EUKARYOTES• MULTICELLULAR HETEROTROPHS

THAT OBTAIN NUTRIENTS BY ABSORPTION

• SECRETE HYDROLYTIC ENZYMES, DIGEST FOOD OUTSIDE THEIR BODIES, AND ABSORB THE SMALL MOLECULES

• CELL WALLS MADE OF CHITIN• BODIES ARE COMPOSED OF

FILAMENTS CALLED HYPHAE THAT ARE ENTWINED TO FORM THE MYCELIUM• HYPHAE ARE DIVIDED INTO CELLS BY

SEPTA• REPRODUCE BY SPORES• NUTRITION MODES INCLUDE

DECOMPOSERS, PARASITES, AND MUTUALISTS

CONCEPT 31.4• FUNGI HAVE RADIATED INTO A

DIVERSE SET OF LINEAGES

FUNGI – 5 PHYLA

• ASCOMYCOTA (SAC FUNGI) – PRODUCE SEXUAL SPORES IN SAC-LIKE STRUCTURES CALLED ASCI – INCLUDE YEASTS AND SORDARIA

• BASIDIOMYCOTA (CLUB FUNGI) – INCLUDE MUSHROOMS- IMPORTANT DECOMPOSERS

• DUETEROMYCOTES – ASEXUAL, QUICK GROWING FUNGUS (MOLDS)

• MYCOPHYCOTA• ZYGOMYCOTA (ZYGOTE FUNGI) –

TERRESTRIAL – PARASITES, COMMENSAL SYMBIONTS

EXAMPLESAscomycota – Yeasts, powdery mildews,

blue-green molds, morels, truffles

Basidiomycota – Mushrooms, smuts, rusts, jelly fungi, puffballs, stinkhorns

Deuteromycota – Imperfect Fungi (parasites that cause diseases of plants and animals)

Mycophycota - Lichen

Zygomycota – Bread mold

CONCEPT 31.5• FUNGI PLAY KEY ROLES IN

NUTRIENT CYCLING, ECOLOGICAL INTERACTIONS, AND HUMAN WELFARE

• IMPORTANT DECOMPOSERS OF ORGANIC MATERIAL INCLUDING CELLULOSE AND LIGNIN

• MYCORRHIZAL FUNGI ARE ASSOCIATED WITH PLANT ROOTS AND IMPROVES THE DELIVERY OF MINERALS TO THE PLANT (MUTUALISM)

• LICHENS – SYMBIOTIC ASSOCIATIONS OF PHOTOSYNTHETIC MICROORGANISMS (ALGAE) EMBEDDED IN A NETWORK OF FUNGAL HYPHAE

• 30% OF FUNGI ARE PARASITES