Question
Which one of the following generally acts as an antagonist to gibberellins?
-
Zeatin
-
Ethylene
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ABA
-
IAA
Solution
C.
ABA
Abscisic acid (ABA) is also called stress hormone. It is a mildly acidic growth hormone which functions as a general growth inhibitor by counteracting other hormones (auxin, gibberellin, cytokinin) or reactions mediated by them. It causes stomatal closure, abscission of flower and fruits while gibberellin helps in opening of stomata and promote development of fruits.
