Plant hormones, also known as phytohormones, are chemical compounds that regulate plant growth and development. These hormones play a crucial role in controlling processes such as seed germination, root growth, flowering, fruit ripening, and responses to environmental stimuli such as light and gravity.
There are five major classes of plant hormones:
1. Auxins: These hormones are involved in promoting cell elongation, root initiation, and apical dominance. They also play a role in tropisms, such as phototropism and gravitropism.
2. Cytokinins: Cytokinins are involved in cell division and growth, as well as in delaying senescence. They work in conjunction with auxins to regulate plant growth.
3. Gibberellins: Gibberellins are involved in stem elongation, seed germination, and fruit development. They also regulate flowering and dormancy.
4. Abscisic acid (ABA): ABA is involved in regulating seed dormancy and stress responses, such as drought tolerance and stomatal closure.
5. Ethylene: Ethylene is a gaseous hormone that is involved in fruit ripening, leaf senescence, and abscission (the shedding of leaves, flowers, and fruits).
These plant hormones work together in a complex network to regulate plant growth and development in response to internal and external signals. By understanding how these hormones function, scientists can manipulate plant growth to improve crop yield, enhance stress tolerance, and develop new varieties with desirable traits.
Plant hormones
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