ABA (Abscisic acid) is called a stress hormone.
a. How does this hormone overcome stress conditions?
b. From where does this hormone gets released in leaves?
(a) Abscisic acid is a stress hormone and during stress conditions, it induces changes like the closing of stomata to prevent further water loss during the scarcity of water, aids in seed germination when conditions are favourable and dormancy when not and other changes as and when required.
(b) This hormone, abscisic acid gets released in the leaves from the mesophyll cells of the plant.