Plant hormones that promote stomatal closure of leaves are

Abscisic acid Abscisic acid is a plant hormone, which can promote leaf abscission and stomatal closure. Under unfavorable conditions such as drought and high salt, a large amount of abscisic acid will accumulate in plants, thus closing stomata to reduce water evaporation and protect plants from environmental pressure. Abscisic acid is a plant hormone that regulates stomatal movement in plants. Therefore, abscisic acid is a plant hormone that promotes stomatal closure of leaves.