Lecture 5b: Mucoromycota, Chytridiomycota and Glomeromycota Flashcards
what are Mucoromycota?
They are a diverse group of moulds
what type of organisms are they commonly?
Saprobes that may be opportunistic pathogens
Which species do they include?
Mucor, Rhizopus, Pilobolus
What if formed when 2 Mucoromycota gametes fuse?
Zygospores
Which type of hyphae does Mucoromycota have?
Coenocytic hyphae. Hyphae that are not septate
What type ogf fungi are Piloblus spp.?
They are Coprophilus (dung-loving)
What type of spore dispersal is observed with Pilobolus spp.?
- They’re hat tossers (wind dispersal)
- which fling spores up to 7 meters away by hydrostatic pressure at the end of the stalk that supports the sporangium
How does Polibolus achieve distance?
the sporangiophore accumulates fluid rich in sugar and ions, which increases the osmolyte concentration and builds turgor pressure inside the bulbous vesicle of the sporangiophore
What does the Chytridiomycota class consist of?
The smallest and simplest fungi and they are ancestors of fungi.
What is the importance of Chytridiomycota?
They degrade plant and animal matter such as cellulose, chitin and keratin
Where are Chytridiomycota usually found?
In freshwater or wet soils
What type of fungi does Chytridiomycota consist of?
Most are parasites of algae and other live on organic matter as saprobes
What strengthens chytrid cell walls?
Chitin
What are thalli?
Feeding structures that absorb nutrients from surroundings, and are transformed into sporangia that release zoospores when nutrients become limited.
How does zoospore release take place?
Release occurs through discharge tubes that expand from the thalli
What anchors Thalli to solid materials?
Rhizoids
What is the asexual state of Chytridiomycota?
Zoospores
They swim to a desirable substrate and attach to it
what happens as the zoospore develops?
The protoplasm increases. Eventually, the cleavage of the protoplasm occurs, which produces individual zoospores that are released through a pore
What is the sexual state of CHytridiomycota?
they are haploid dominant.
gametothallus
What are gametothallus?
They are haploid thalli that produce female and male gametes
How are male gametes attracted to the female games?
The female gametes produce the hormone sirenin, and the female gametes are attracted to the male gametes when they produce the hormone parisin (chemotropism)
What is Chymitridiomycosis?
and emerging fatal infectious diseases of amphibians caused by Batrachochytrium dendrobatidis
Where did Chymitridiomycosis originate from?
Africa 1938
Where are fungi that cause chytridiomycosis reside in the host organism?
In the keratinised tissue, which includes the mouthparts and tadpoles
What are the symptoms of chytridiomycosis?
thickened epidermis- cannot take in proper nutrients, release toxins and in some cases breathe. reddening of the ventral skin
Behavioural changes caused by chytridiomycosis?
lethargy (lack of energy), failure to seek shelter, failure to flee, loss of righting reflexes and abdominal posture
What does the class of Glomeromycota consist of?
A group of soil-borne fungi that form endomycorrhizal associations with land plants or cyanobacteria
What is the significance of Glomeromycota?B
They play an important role in the initial colonization of terrestrial areas
Characteristics of glomeromycota
- biographic nature and obligate symbiont
- hyphae are coenocytic
The asexual state of Glomeromycota
Blastic development of spores from hyphal tips
Distributive hyphae
Hyphae that are relatively large and branch infrequently. their primary purpose is to connect different parts of the fungi
Absorptive hyphae
Hyphae that are thin, short and highly branched, are used to extract nutrients from the soil
What do Glomeromycota produce in plant roots?
In plant roots, they produce hyphae, arbuscles and vesicles
Linear hyphae
Linear hyphae grow in air spaces between the root cells and are straight as the root structure permits
Coiled hyphae
Grow inside cells and grow directly from one cell to the next. they are not as limited by root structure and can follow a more winding path
Arbuscles
Are highly branched intracellular structures with a very high surface area, which allows for an efficient exchange of nutrients and sugars
Vesicle
Is an inflated area of the hyphae that functions as a store structure. they may resemble and function as spores
