Bhawna bhardwaj ,Subject matter expert at edumarz
Solution: Phytohormones are another name for plant hormones. Plant hormones are chemical substances produced by plants and found in low concentrations in plants. They are in charge of the plant’s growth and development. Phytohormones promote cell division, prevent senescence, and maintain dormancy. Plant hormones play an important role as signaling molecules. Plant hormones are essential regulators of plant development.
Plant hormones are synthesized in almost all plants and transmitted to different parts of the plant.
There are five types of phytohormones in plants:-
Auxin
Gibberellins
Cytokinins
Abscisic acid
Ethylene gas
Plant hormones play an important role in seed germination, dormancy,and vernalization.
Background;Plant hormones can be natural or synthetic.
Based on their action ,plant hormones are of two types;
Plant growth promoters
Plant growth inhibitors
Auxin
Auxin means “to Grow”.Auxins are produced at apical meristem. auxin helps in the elongation of root and stem cells.
Natural derivatives:-Indole butyric acid, Indole -3-acetic acid
Synthetic derivatives:-Naphthalene acetic acid, 2,4-dichloro phenoxy acetic acid.
Gibberellins
Gibberellins is acidic phytohormone.it promotes stem elongation. Gibberellins control parthenocarpy.
Natural derivatives: Terpenes in different forms.
Cytokinin
Cytokinin mainly regulates the process of cytokinesis. Cytokinin promotes the lateral growth of shoots.
Natural derivatives:-Zeatin, isopentenyl adenine.
Synthetic derivatives:-Diphenyladenine, kinetin.
Abscisic acid
Abscisic acid is the growth-inhibiting hormone that works against the gibberellins.it is also known as the “stress hormone”.
It stimulates the closing of the stomata.
It induces leaf senescence.
Ethylene
Ethylene acts as both inhibitors as well as promoter.