SSC MTS EXAM

Detailed explanation-1: -Among these, abscisic acid (ABA), is the best-known stress hormone that closes the stomata, although other phytohormones, such as jasmonic acid, brassinosteroids, cytokinins, or ethylene are also involved in the stomatal response to stresses.

Detailed explanation-2: -Abscisic acid-induced stomatal closure is mediated by ion efflux from guard cells. Ion efflux in turn leads to osmotic water efflux and a reduction in the turgor and volume of the guard cells, resulting in stomatal closure.