examples of physiological processes taking place in plants due to hormones

Answer 1

1. Growth and development: Plant hormones play a crucial role in regulating the growth and development of plants. For example, auxins promote cell elongation in shoots, cytokinins stimulate cell division and growth in roots and shoots, and gibberellins help in stem elongation.

2. Seed germination: Hormones like gibberellins and abscisic acid regulate seed germination processes. Gibberellins break seed dormancy and promote germination, while abscisic acid inhibits germination and maintains seed dormancy during unfavorable conditions.

3. Flowering: Hormones like gibberellins and cytokinins regulate flowering in plants. Gibberellins promote flowering by stimulating the formation of floral organs, while cytokinins delay senescence and promote flower bud development.

4. Leaf senescence: As plants age, their leaves undergo senescence and eventually die off. This process is regulated by hormones like ethylene and abscisic acid. Ethylene promotes leaf senescence, while abscisic acid accelerates this process.

5. Root development: Auxins play a significant role in root development. They stimulate the elongation of root cells, promote root branching, and enhance the formation of lateral roots.

6. Fruit ripening: Hormones like ethylene and abscisic acid regulate the ripening of fruits. Ethylene triggers the production of enzymes that break down cell walls and soften the fruit, leading to ripening. Abscisic acid controls the color change and accumulation of sugars in ripening fruits.

7. Tropisms: Hormones are involved in plant movements in response to various stimuli. For example, auxins regulate phototropism (bending towards light) and gravitropism (root growth towards gravity) in plants.

8. Defense mechanisms: Plant hormones play a role in activating defense mechanisms against various stress factors, such as pathogens, insects, and drought. Jasmonates and salicylic acid are involved in the plant's response to pathogen attack, while abscisic acid regulates the plant's response to drought stress.

9. Abscission: Hormones like ethylene initiate leaf and fruit abscission (shedding) in plants. Ethylene promotes the breakdown of cell walls, leading to detachment of leaves and fruits from the plant.

10. Stomatal regulation: Stomata are tiny openings on plant leaves that control gas exchange and water loss. Hormones like abscisic acid regulate stomatal closure, reducing water loss during drought conditions.