Agrobacterium Flashcards
What is Agrobacterium tumefaciens? Where is it normally? How does it work?
A plant pathogen cable of causing disease: crown gall in broad leaf plants.
Normal in soil.
Finds entrance in wound/graft of plant. It causes tumor like growth- gall.
Why is the disease called crown gall?
Normally happens at plants root crown.
The pathogenicity of Agrobacterium is mediated by what?
Ti (tumor inducing) plasmid.
What does Ti do?
Bacterium transfers plasmid to plant cell where it’s integrated into genome.
This plasmid contains DNA encoding plant growth hormones that cause uncontrolled growth.
Also encodes production of opines that few other organisms other than Agrobacterium can use to receive C and N.
How is Agrobacterium a good example of genetically engineered organisms?
Makes plant cells produce opines which are amino acid derivatives only usable to a few organisms such as Agrobacterium itself. It engineers the plant to produce nutrient sources that only it can really use.
How can Ti plasmid be used by researchers?
Provides way for researchers to insert desired genes into plants. Possible to alter Ti plasmid to include genes encoding desirable traits such as toxin synthesis. Making plants make their own insecticides.
