Biological Control Flashcards
What are Biological Control Agents?
They suppress a pathogen by occupying niches and they induce the plant defence response.
What are the fungal biological control agents?
Mycoparasites - protects against grape powdery mildew.
Trichoderma spp. - protect against other soil bourne fungi.
Muscodor albus - protects against Brown rot.
Phlebiopsis gigantea - kills butt rot
Hypoviralent fungi - stops fungus chestnut blight by turning aggressive virulents into hypoviralent fungi.
What are the bacterial biological control agents?
Bacillus thuringiensis (Bt) - protects against insects such as the Cotton bollworm and the European corn borer.
Bacillus subtilis - protects against soft rot of potato caused by Erwinia carotora.
Pseudomonas fluorescens - protects against frost caused by ice nucleating bacteria.
Agrobacterium radiobacter - protects against crown gall disease by killing Agrobacterium tumefaciens.
How is biological control initiated in the plant itself?
Systematic resistance triggered by UV-C light and/or microbes allows for a degree of resistance.
TrDNA of Agrobacterium tumefaciens is inserted into the plants genome to induce resistance.
Can also insert bits of a pathogen into the plant genome (bit like a vaccine). (Bit problem is then the plant is only immune to that one disease).
Give 3 examples of viruses that have been inserted into a plant genome to infer resistance to the virus.
1- Apple mosaic virus
2- Enzyme ROCTase is engineered into tobacco plants to make it resistant to phaseolotoxin (a toxin produced by Pseudomonas syringae)
2- Some proteins (killer toxins) have been engineered into wheat plants in order to be resistant to maize smut (ustilago maydis).
