Answer:
Plant Growth Regulators are defined as small, simple chemicals produced naturally by plants to regulate their growth and development.
Characteristics
Plant Growth Regulators can be of a diverse chemical composition such as gases (ethylene), terpenes (gibberellic acid) or carotenoid derivates (abscisic acid). They are also referred to as plant growth substances, phytohormones or plant hormones. Based on their action, they are broadly classified as follows:
Plant Growth Promoters – They promote cell division, cell enlargement, flowering, fruiting and seed formation. Examples are auxins, gibberellins and cytokinins.
Plant Growth Inhibitors – These chemicals inhibit growth and promote dormancy and abscission in plants. An example is an abscisic acid.
Note: Ethylene can be a promoter or an inhibitor, but is largely a Plant Growth Inhibitor.
Browse more about Plant Growth and Development
Plant Growth and Development
Growth and its Phases
Vernalisation
Photoperiodism
All plant growth regulators were discovered accidentally. Let’s take a detailed look at each regulator and learn about it more closely: