What are plant growth regulators?



What are plant growth regulators? Name any for different chemical nature of them with one example of each.
Plant growth regulators are small, simple molecules secreted in minute quantities, that influence various physiological functions in plants. They are of diverse chemical composition.


(i) Indole compounds such as- indole-3- acetic acid (IAA)
(ii) Adenine derivatives such as kinetin, 6- furfuryl amino purine
(iii) Derivatives of carotenoids such as abscisic acid (ABA)
(iv) Terpenes [such as gibberellic acids]