Question

name the following the pgr that causes apical dominance​

Answer 1

Answer:

Auxin hormones maintain apical dominance, they increase the growth of shoot and inhibit the growth of lateral buds. When lateral bud present in the axil of the leaves does not grow to form branches it is known as apical dominance.

Answer 2

Answer:

Auxin, cytokinin, and other unknown substances are thought to regulate apical dominance.482 Application of cytokinin or overexpression of the IPT gene shows a phenotype with a reduction in apical dominance.404,483,484 Arabidopsis mutants with increased levels of cytokinin also show reduced apical dominance.485–487 These results suggest that cytokinins play a role in the promotion of bud outgrowth.

Studies using pea have suggested that decapitation leads to increased levels of endogenous cytokinins in the stem and/or xylem sap488,489 and increased delivery of cytokinins to axillary buds.490,491 Decapitation of pea leads to increased cytokinin levels in axillary buds following an induction of IPT genes in the stem.491 These lines of evidence suggest that cytokinins synthesized in the stem are transported to the axillary buds after decapitation, resulting in promotion of bud outgrowth. Increases in cytokinin levels and pea IPT expression after stem decapitation are partially repressed by auxin application.489,491 It is not clear whether an increased cytokinin level in buds occurs prior to bud outgrowth, or is the cause of bud outgrowth.