AM FUNGI

AM FUNGI

• Also known as glomeromycota
• "AM" fungi stands for arbuscular mycorrhizal fungi
• Previously classified as zygospores; now have have their own group
• Supposed to have existed 460 million years before plants
• There are almost 220 species in existence

CHARACTERISTICS

• Obligate symbionts
• Formation of arbuscules in plant roots
• Large, multinucleate spores with layered walls
• Nonseptate hyphae
• Found in soil

STRUCTURE

• They are a relatively small group
• Arbuscules create branching veins when invading plant roots
• Mychorrhizae have a mutualistic association with plants

MUTUALISM WITH PLANTS

• Most common type of fungi to create a relationship
• The majority of plants have symbiosis with AM fungi
• Improves the supply of water and nutrients to the plant
• Transport of nutrients occurs in the arbuscules of the fungi
• The fungi improve soil quality and density

MUTUALISM WITH CYANOBACTERIA

• Called Geosiphon pyriformis
• Only fungus in endosymbiosis with cyanobacteria
• Naturally abundant in the Spessart Mountains (Germany)

REPRODUCTION

• Spores are formed asexually
• The fungi germinates and forms new spores
• The new spores establish new mychorrrizal symbiosis
• If no host root is found, they become dormant
• Some species can be recreated by culturing in a lab

SOURCES

• Redecker, Dirk. "Glomeromycota."
• Kluge, Manfred. "A Fungus Eats A Cyanobacterium".
• No author. "Arbuscular Mychorrizal Fungi and their Symbiosis with Plants."
• Redecker, Dirk and Philipp Rabb. "Phylogeny of the Glomeromycota"
• Parniske, Martin. "Arbuscular Mychorriza: The mother of plant root endosymbiosis."

VOCAB

• Glomeromycota - one of the seven phyla of the Fungi kingdom
• Zygospore- a thick wall that grows around a zygote during the reproduction cycle
• Arbuscule- the result of a mycelium growing into the cells of the host plant
• Mychorriza - a symbiotic relationship between a fungi and a plant
• Geosiphon pyriformis- the only species of fungi that forms a relationship with cyanobacteria

VOCAB CONT.

• Nonseptate hypha- A hypha that is undivided
• Obligate symbiosis- Symbiosis required by both organisms to survive

THE END