Question

Explain and provide specific examples of how hormones regulate every aspect of plant growth from seed to leaf abscission.

Answer 1

Plant hormones may promote or inhibit the growth of plants.,it depending on the specific hormone involved, the concentration, the time, and the plant part it is acting on. Plant hormones occur naturally. when they are synthesized chemically they are known as plant growth regulators. Plant growth hormones can be grouped into 5 classes of compounds; auxins, gibberellins, cytokines, abscisic acid, and ethylene

hormones	typical activities
auxin	promote stem elongation , adventitious root initiation, and fruit growth; inhibit axillary buds outgrowth and abscission
abscisic acid	maintains seed dormancy and winter dormancy; closes stomata
brassinosteroids	promote stem and pollen tube elongation, promote vascular tissue differentiation
cytokinins	inhibit leaf senescence; promote cell division and axillary bud outgrowth; affect root growth
ethylene	promotes fruit ripening and leaf abscission; inhibits stem elongation and inhibits stem elongation and gravitropism
gibberellins	promote seed germination, stem growth, and fruit development; mobilize nutrient reserves in grass seeds
jasmonic acid	initiate the production of defence proteins against parasites
strigolactones	inhibition of shoot branching