Week 20: (D) Case Study; submergence tolerant rice Flashcards
Why is the agricultural revolution- submergence tolerance important?
more than 16 million ha of and used to grow rice in:
lowland areas
deep-water areas
both are unfavourably affected by flooding
Can rice cope with flooding?
NO, most rice us sensitive rice, cannot survive prolonged flooding
Why does rice die after flooding?
it continues to grow, expends a lot of energy–> becomes very spindly & thin.
When the water retreats the rice falls over
DEAD
COMPLETE LOSS
What rice is flooding tolerant?
Submergence- tolerant Sub1a rice
How does Sub1a cope with flooding?
growth arrest during flooding, enhancing survival.
altering its growth response
What hormone is produced by plants (lowland rice)?
ethylene accumulation
What is the effect of the hormone ethylene? (non-tolerant)
inhibits ABA accumulation
What is the effect of inhibited ABA? (non-tolerant)
Allows GA to respond = shoot elongation
not favourable
What effect does ethylene have in submergence tolerance lines?
promotes expression of a gene called SUB1A.
What does SUB1A do?
SUB1A promotes the expression of 2 DELLA genes- SLR1.
What is the effect of a DELLA gene?
Inhibit GA
inhibit growth response
What does Marker Assisted Selection do?
selecting for DNA markers is faster than selecting for phenotypes
Tell us about the trait we are interested in
How do you carry out MAS?
do a screening of a gene then use markers to let us see which genes each individual has inherited
Detect markers that are specific to sub1a
