fungal cell biology Flashcards
fungi are essential for
plant survival
two major forms of fungi growth
yeast and hyphae
over 95% of all angiosperm plants
form mycorrhizal symbiosis with fungi
mycorrhizal symbiosis
symbiotic association between a fungus and the roots of a vascular host plant.[
yeast
uni-cellular and round–> grow via budding
hypha; cells
multi-cellular and elongated –> grow via extension
dimorphic fungi grow as both
years and hyphae
septa pore
allows communication between hyphae in hyphen cell
hyphae growing
grow based on gradient of secretion –> if there is more growth material at one end it will grow in that direction
some hyphae will have no
septa
fungal grown requires
delivery of vesicles to the growth region
what supports growth
the cytoskeleton–> transport towards the bud or the hyphae tip
what support motility
fungal motors–> dyne and kinesin
movement occurs via
actin and microtubule
actin and microtubules also help to
shape the fungi
long transport occurs along
microtubules
actin patches are involved in
endocytosis
what transport material into the bud
myosin 5 motors via continuous secretion- isotropic growth
fungal spitzenkorper
used in hyphae growth
-consists of vesicles and determines where hypha grows.
spitzenkorper known as the
vesicle supply centre – the vesicles are released and fuse with he plasma membrane
what type of secretory vesicles in a spitzenkorper
secretory and endocytic recycling vesicles
what determines hyphae growth
the rate of vesicle release and motility §of the spitzenkorper
steps of the spitzenkorper
1) transport along the cytoskeleton
2) storage of vesicle in spitzenkorper
3) release and fusion with plasma membrane
woronin bodies
a peroxisome derived, dense core micro body with a unit membrane found near the septa that divide hyphae compartments in filamentous ascomycota
where are woronin bodies found
filamentous ascomycota
problem of multi-cellularity
concerns of maintenance of cooperation among the components off individual organism
years and single cellularity
when one cell dies, no other dies
hyphae and multi cellularity
when one cell of the hyphae dies, all cells die
how do hyphae cells get isolated so that not all die
woronin bodies
who first described woronin bodies
mycologist M.Woronin 1864
where are woronin bodies concentrated
around the septal pore
specialised peroxisomes
woronin bodies that plug the septa in filamentous ascomycetes
woronin bodies form by the self assembly of
the protein Hex1–> when the cell gets wounded
mushrooms release spores for
reproduction
why is a mechanism of spore discharge needed in basidiomycetes
there is no wind in the gills
mechanism of spore discharge in basidiomycetes
1) basidiospore sits on sterigmas
2) two water droplets form due tot he secretion of mannitol and other hydroscopic sugars on the surface of the spore
3) Bullers drip increases in size due to recruitment of atmospheric water
4) sudden change in gravity by fusion of both drops create a propulsive force
5) forces the spore to fall off the sterigma
spore distribution by Bullers droplet
max a few mm
- speed up to 1.8m/s
- acceleration 9000x faster than a sports car
Turgor
method of spore discharge–> pressure builds up to 100-700 in the sporangium
–> shooting distance can be up to 2m
spore distribution by rains plash in
basidiomycetes
