what are plant hormones. write its significance
Answers
Answer:
There are five major plant hormones which are Auxin, Cytokinin, Gibberellin, Ethylene and Abscisic acid.
Functions of these hormones are as follows:
1. Auxin
Auxin induces cell elongation, maintains apical dominance, initiates root formation, prevent abscission, induces parthenocarpy and is used as herbicide also in synthetic forms.
2. Cytokinin
Cytokinin promotes cell division and organ formation, delays senescence, promotes lateral bud development, enhances cell expansion in cotyledons leaves, promotes Chloroplast development and Chlorophyll synthesis.
3. Gibberellin
Gibberellin promotes stem elongation, seed germination, breaks dormancy, causes elongation of internodes and induces parthenocarpy.
4. Ethylene
Ethylene promotes fruit ripening.
5. Abscisic acid (ABA)
ABA induces stomatal closure, provides stress against salt stress, induces dormancy, causes abscission.