Botany - Plant Growth and Development Question with Solution | TestHub

Abscisic acid (ABA) is also called stress hormone. It is a mildly acidic growth hormone which functions as a general growth inhibitor by counteractig other hormones (auxin, gibberelliun, 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.