Agriculture - Plant Genes Flashcards
Where can plant transformation be applied?
Addition of new genes from other organisms/plants
Expression of existing genes can be modified
Genes can be delted
Increase of yield
Transgenisis
This is the insertion of a foregin gene into an organisms genome, with germ-line transmission of the gene following.
What agronomic traits can be changed?
Herbicde Tolerance
Pest/Disease resistance
Resistance to Abiotic Stress
What qualities of agriculture are looking to be enhanced?
Processing
Shelf-life
Reduced anti-nutriens
Nutrional quality
Reduction of oils
Why are herbicdes important?
Killing of weeds growing in crops, as weeds compete for nutriens and water, reducing yield
Mechanism of action of Glyphosate…
Targets the 5-enoppyrivylshikimate-3-phosphate synthase, preventing aromatic amino acid biosynthesis, disallowing metabolite/protein productio.
Biochemical envrionmental affects of Glyphosate…
Curvs energy pathways in soil microbes and plants, reducing microbial richness and increasing fungi
Environmental affects of Glyphosate…
Organ failure of non-mammalian species, inhibting acetylcholinesterase, as well as APA derivatives affecting RBC in humans and chromosomal aberrations in fish.
How can glyphosate be degraded envrionmentally?
UV light application, photocatalysis reducing to CO2, water and inorganic ions
Resistance to Glyphosate…
Alternatives of 5E3PS found in bacteria.
Pros of herbicide tolerance…
Increased crop productivity, encouraging no-till agriculture and GHG emissions
Cons of herbicde tolerance…
Increased glyphosate selects for super-weeds, or reduction in biodiveristy.
Example of insect resistance genes…
B.thuringiensis produces crystal(Cry) proteins during sporulation
When was Cry proteins first used?
1938
Mechanism of action of Cry proteins…
Bind receptors in the guts of target insects, being non-toxic to other animals.
How is Cry proteins activated?
Larvae consume toxin, crystals solubilised then activated by proteloytic cleavage in mid-guit, binding receptors, triggering cell death.
Cry proteins using against different groups of insects…
Maize uses cry1AB for MON810 conffering resistance against European stem borer
Pros of Insect resistance?
Increase of yield, reducing envrionmental impact, improve farmer health and food quality, reducing Alfatoxins
Cons of insect resistance?
Selection pressure of resistant pests, potential effects on pollinators.
Social downside of herbicide and insect resistance?
Primarily benefical to the farmers and chemical companies, not those consuming the food.
Example of improving nutritional quality?
Golden rice with increased Vitamin A levels
Symptoms of Vitamin A deficiency?
Xerophthalmia, death susceptibility(125million children suffer from VAD, 1-2.5million children die.
Where is golden rice gene sourced?
B-carotene biosynthesis pathways in daffodils introduced into transgenic rice.
Con of golden rice?
Reinforces dependence on rice in diet, better to increase diversity of diet.
