Plant growth substances / Plant hormones

Plant growth substances / Plant hormones / Plant growth regulators

                Plant growth regulators are also known as plant growth substances and plant hormones. Plant growth regulators are signalling molecules that are produced in small quantities. Plant growth regulators are transported from the place of produce to other parts of the plant, where triggers responses in target cells. Plant growth regulators are organic compounds that can be natural or synthetic. Plant growth regulators can modify or control specific physiological processes in plants. The main plant growth regulators are auxin, gibberellin, cytokinin, abscisic acid, ethylene, and jasmonates.

 

Auxin

                Now let us talk about auxin. Auxin is a plant growth regulator. Auxin stimulates stem elongation in low concentrations. Auxin promotes the formation of the lateral adventitious roots. And it regulates the development of fruits. Auxin enhances apical dominance. Auxin functions in phototropism and gravitropism. It also promotes vascular differentiation and retards leaf abscission.

 

Gibberellin

                Gibberellin is also a plant growth regulator. Gibberellin stimulates stem elongation. Gibberellin also stimulates pollen development and pollen tube growth. It also functions in stimulation of fruit growth. Gibberellin works in stimulation of seed development and germination. Gibberellin regulates sex determination and transition from juvenile to adult phase.

 

Cytokinin

                As a plant growth regulator cytokinin also has different tasks. Cytokinin regulates cell division in shoots and roots. This plant growth regulator modifies apical dominance and lateral bud growth. Cytokinin promotes movement of nutrients into sink tissues. And cytokinin stimulates seed germination and delay leaf senescence.

 

Abscisic acid

                Abscisic acid is also a well-known plant growth regulator. Abscisic acid does inhabitation of growth. It also plays a key role in promoting stomata closure during drought stress. Abscisic acid promotes seed dormancy and inhibits early germination. Abscisic acid also promotes leaf senescence and promotes desiccation tolerance.

 

Ethylene

                Ethylene is also a plant growth regulator found in plants. Ethylene is well known for promoting the ripening of many types of fruit. Ethylene promotes leaf abscission. Ethylene also promotes triple response in seedlings. Triple response in seedlings means inhibition of stem elongation, promotion of lateral expansion, promotion of horizontal growth. It also enhance the rate of senescence. Ethylene promotes roots and root hair formation. Also, ethylene promotes flowering in the pineapple family.