Q. Read the following functions performed by plant hormones:
a) regulates dormancy
b) inhibits metabolism
c) stimulates stomatal closure
d) inhibits seed germination
Which of these is involved in ALL of the above functions?

 2022  189 NTA AbhyasNTA Abhyas 2020Plant Growth and Development Report Error

Solution:

Abscisic acid (ABA) was discovered for its role in regulating abscission and dormancy. But like other PGRs, it also has other wide ranging effects on plant growth and development. It acts as a general plant growth inhibitor and an inhibitor of plant metabolism. ABA inhibits seed germination. ABA stimulates the closure of stomata in the epidermis and increases the tolerance of plants to various kinds of stresses. Therefore, it is also called the stress hormone. ABA plays an important role in seed development, maturation and dormancy. By inducing dormancy, ABA helps seeds to withstand desiccation and other factors unfavourable for growth.