Week 20: (A) Plant Science: Genetic Modifications

Question 1

What are the potential benefits to genetic modification?

Answer 1

• Overcome linkage drag, “clean” gene movement
• Introduce novel abilities
• More rapid breeding cycles
• Increased food production
• Improved human nutrition (Vitamin A, Omega 3….)
• Wealth redistribution
• Open up marginal land
• Increase land and water use efficiency
• Reduced environmental impact (CO2, NOx)
• Reduced fertilizer use
• Reduced herbicide/pesticide/fungicide/bactericide use
• Reduced soil damage

Question 2

What are the potential problems of genetic modification?

Answer 2

• Commercial interests
• Loss of ecological diversity (herbicide/pesticide/fungicide resistant crops)
• Gene transfer to wild relatives

Question 3

What are 2 examples of natural gene transfer?

Answer 3

1) Agrobacterium spp, produce root galls, to make the galls agroB transfer some go its own genes into the plant= reprogram cells and code for enzymes that the bacterium needs
–> horizontal gene transfer.
-Usually just somatically passed on but the branch could fall off and be take up by another species due to pluripotent nature
e.g. linaria vulgaris and nicotiana glauca
called speciation.
2) Sweet potato, naturally genetically modified by agrobacterium species= more nutritiuos

Question 4

What is the cost/benefit of GM ?

Answer 4

• increase in crop yield ~20%
• profit increased (spend less on crop and get more for it)
• Reduces pesticide use, reduced carbon footprint as less tractors in field.
• Not spraying pesticides increase insect diversity, maintain ecological diversity of surrounding landscape
• maintain soil structure, as less herbicides, pesticides, fungicides

Question 5

Do plants have an adaptive immune system?

Answer 5

no, only innate

Question 6

What is an issue of traditional breeding to survival of plants?

Answer 6

reduced genetic diversity means they cannot adapt

Need to recover genetic diversity present in the wild pops that allows resistance to be the norm.

Question 7

how long does it take to move a gene naturally?

Answer 7

~25 years

Question 8

How quick is it to gene transfer using GM?

Answer 8

~24 months and is independent of how many genes

Question 9

How can nitrogen fixing cereals use GM?

Answer 9

nitrogen has a high carbon footprint and can contaminate waters.
Plants such as peas and beans can naturally nitrogen fixation ( self-fertilising)

Question 10

How have plants contributed to medicine?

Answer 10

Poppys = morphine
quinine = tonic flavouring
willow = (Aspiring) salicylic acid (pain killer)
foxglove = Antopine drug used for cardiac glycosides (heart arrhythmia)

Question 11

What are some percents of how plants contribute to modern medicine?

Answer 11

~55% of drugs owe their origins to plants
~25% of all drugs are still made directly from plants
~60% of anti-cancer drugs are of plant origin

Question 12

What ind of metabolic diversity do plant have?

Answer 12

high

as they cannot adapt to threatsNaturally produce anti-microbial and anti-herbivory compounds

Question 13

Why start with natural products in drug discovery?

Answer 13

If it has been pre- screened in folk medicine it has an effect on people.
Unlikely to be lethal as it has survived as a remedy
Active in cell, must be metabolic benefit= higher chance of biological activity
-People from the area the plant is from can benefit, farming the crop.
=Community benefit

Question 14

What compound kills malaria?

Answer 14

Artemisinin

Question 15

What are the benefits of plants as medical bioreactors?

Answer 15

• Many post-translational modifications are maintained, —–can also be “humanised”
• Maintain stereochemistry
• Cheap to grow
• Store as seed for when needed
• Edibility
• Interleukin, Interferon, Factor VIII, hGH