Plant Growth and Development Question 23
23. Which one of the following growth regulators is known as ‘stress hormone’?
(a) Abscissic acid
(b) Ethylene
(c) $GA_3$
(d) Indole acetic acid
Show Answer
Answer : a
Hints & Solutions
(a) Abscisic Acid $(ABA)$ is called stress hormone which works in adverse environmental condition when there is low water content in atmosphere or in drought conditions. ABA causes the stomatal closure of leaves due to which the water loss by the plant is minimized.