Week 20: (C) Plant development and food security

Question 1

What is crop domestication?

Answer 1

Wild cereal–> cultivation and domestication–> landraces (selective breeding)–> modern cereal

Question 2

What happens to a crop when it is domesticated?

Answer 2

developmental traits that increase grain yield
Loss of vernalisation requirement
Increase seed number 
Reduced seed shattering
Reduced height

Question 3

What is the effect of developmental genes?

Answer 3

Responsible for domestication

change genetics of the crop plant

Question 4

What is an example of changes in developmental genes responsible for domestication?

Answer 4

Rice gene qSH1 controls abscission zone formation at base of rice flower (reduced seed shattering, very imporntant)

Question 5

What determined whether an obsession zone is made or not?

Answer 5

a SNP in the regulatory (not coding region) on the qSH1 gene. 1 nucleotide polymorphism.
A single transcription factor responsible for non-shattering rice.
This section is what we use today!

Question 6

What was created in the green revolution?

Answer 6

semi-dwarf varieties

pushed yield higher than ever before

Question 7

What was the effect on GA for plants during the revolution?

Answer 7

gibberellin hormone
The ability for a plant to perceive GA was inhibited
reduce stem elongation, plant grows to just the waist

Question 8

What protein enables growth in a plant?

Answer 8

breakdown of the active DELLA inhibiting protein

Question 9

How does GA inhibit DELLA?

Answer 9

Active form of GA (GA bound to GID1) binds to DELLA.
This attracts SCF and Ub factors
Eliminated and allow growth
inhibition of an inhibitor

Question 10

What factors stimulate GA production?

Answer 10

To respond to environmental factors 
1) submergence 
2) shade avoidance 
3) cold 
4) salt 
5) drought
3,4,5 = don't want to grow --> inhibit GA

Question 11

What are the 2 important green revolution genes?

Answer 11

DELLA & GA20ox

GA pathway cannot work in the same way