Question

How do plant hormones affect plant growth and development?

Answer 1

Plant hormones :

1. Plant hormones are chemical molecules that regulate plant development and responses to the environment.
2. Some plant hormones are auxin, cytokinins, gibberellins, abscisic acid, ethylene, etc.

Role of auxin:

1. It promotes stem elongation.
2. It initiates lateral bud outgrowth.
3. It promotes leaf abscission.
4. It prompts adventitious roots.
5. It also helps in fruit growth.

Role of gibberellins:

1. It promotes seed germination.
2. It also accelerates stem growth.
3. It breaks dormancy.
4. It helps in fruit development.

Role of cytokinins:

1. It promotes cell division and lateral bud outgrowth.
2. It affects the growth of roots.
3. It inhibits root senescence.

Role of ethylene:

1. It inhibits stem elongation.
2. It promotes fruit ripening and leaf abscission.

Role of abscisic acid:

1. It closes the stomata.
2. It maintains seed dormancy and winter dormancy.