Week 2: Fungal Growth and Morphogenesis II - 4 - insect pathogens Flashcards
How do many fungal pathogen death of insect?
Many fungal pathogens - death caused by tissue destruction and toxins
How do fungi penetrate the host cuticle?
Fungi use enzymes and mechanical force to penetrate host cuticle
What are nematode-trapping organisms?
(other small organisms)
these are fungi which can ensnare or tap insects by nets, nooses and sticky nobs…
What happens when the fungus enters the host body?
mycelium can expand
fungus ramifies the tissues of the host
How does a noose ensnare nematodes?
noose comprises 3 cells forming circle (noose).
when this organism is stimulated by an organism passing through the snare.
cells rapidly takes up water and expand, restrict themselves around the nematode and trap it
hyphae can grow out form tis snare into the host and utilise the host for nutrients.
What 2 fomrs can the captire organs be?
constituitive or inducible
What is the inducible form of capture organs?
induces by presence of nematodes (peptides secreted by them) grows saprotrophically in absence
What does it mean to grow saprotrophically?
organism feed off of dead matter/organic matter
Do the capture organs have species specificity?
no
How long does it take for a capture organ to trap a nematode?
penetrate nematode within 1 hour of capture
What are the basidiomycetes?
fungus which include, toadstools, mushroom
Do many wod degrading basidiomycetes form traps?
YES, SUPPLEMNT NITROGEN IN ITS DIET.
Low nitrogen environment
Why do the wood degrading basidomycetes trap organism?
wood is made of carbon hydrogen and oxygen.
so need to obtain nitrogen
Can the capture organisms fungi be used as a biological control?
YES, e.g. to control plant damaging soil nematodes and animal parasitizing nematodes
