Plant growth regulators, also known as plant hormones or phytohormones, are a group of naturally occurring or synthetic chemical substances that regulate various aspects of plant growth and development. These regulators play a crucial role in controlling processes such as cell division, elongation, and differentiation, as well as coordinating various physiological responses in plants.
There are five major classes of plant growth regulators: auxins, gibberellins, cytokinins, abscisic acid, and ethylene. Each class of plant growth regulator has unique functions and effects on plant growth.
Auxins, for example, are primarily responsible for promoting cell elongation, as well as root development and apical dominance. Gibberellins are involved in stimulating stem elongation, seed germination, and flowering. Cytokinins play a key role in promoting cell division and differentiation in plants and can influence a wide range of growth and developmental processes, including shoot and leaf growth, root growth, and nutrient transport.
Abscisic acid is involved in regulating plant responses to environmental stresses, such as drought and cold, as well as seed dormancy and germination. Ethylene is a gaseous plant growth regulator involved in diverse processes, including fruit ripening, leaf and flower senescence, and response to stress.
Plant growth regulators have numerous applications in agriculture and horticulture. They can be used to control plant height, promote flowering or fruiting, delay senescence, improve fruit quality, enhance seed germination, and regulate plant responses to various environmental stresses. Additionally, they can be utilized in tissue culture techniques and micropropagation to induce in vitro rooting or shoot proliferation.
