Stress tolerance in plants

Question 1

How has Arabidopsis been mutated to be tolerant to drought?

Answer 1

1. Edt1 mutant that mutates a homeobox leucine zipper protein that is involved in trichome branching
2. increased nuclear factor-Y B subunit -> transcription factor that improves tolerance

Question 2

How has Arabidopsis been mutated to be tolerant to salt?

Answer 2

• expression of choline oxidase (a gene found in the chloroplasts of soil bacteria) that converts choline to glycine betaine in 1 step (vs choline->betaine aldehyde->glycine betaine

Question 3

How has rice been mutated to be tolerant to drought?

Answer 3

expression of HARDY ->transcription factor that improves water use efficiency (e.g. by increasing the number of bundle sheath cells)

Question 4

How has Tomato been mutated to be tolerant to salt?

Answer 4

over expression of AtNHX1, a vacuolar Na+/H+ antiporter from Arabidopsis. stops salt accumulation in fruit

Question 5

How has durum wheat been mutated to be tolerant to salt?

Answer 5

ancestral wheat gene TmHKT1 in the Nax2 locus, excludes sodium from cell with transporter
expressed in root cells

Question 6

Pea DNA helicase 45 (PDH45)

Answer 6

unwinds DNA in the 3’ to 5’ direction, increases transcription in cells
has improved salt tolerance in tobacco and canola

Question 7

Soybean

Answer 7

over expression of GmPIF4b that improves heat tolerance