List five plant growth hormones and briefly describe their roles.
List five plant growth hormones and briefly describe their roles.
- Auxin
- Gibberlins
- Cytokines
- Absisic acid.
- Ethylene
Auxin; They have a prominent role in entire growth of plant. They guide the seedling during germination of plant from seed stage in such a way that roots go intosoilwhile stem moves up towards the sun. So auxin does it by phototropism (moving tolightfor stem) and geotropism (moving towardssoilfor roots) mechanism.
Further they promote plant elongation towards the sky and also towards the ground deeper by stem and roots respectively. This auxin is highly active in the tips of shoot (stem) and also root tip.
They induce cell elongation, inhibit falling of leaves and accelerate flower formation.
Gibberlin: These have a different role in promotinggrowth. They specially focus on elongating the nodes and also forming internodes. Nodes are those ridges or ring like structure seen on the stem of a bamboo, sugarcane etc. These gibberlins enhance elongation of a node and when the node is long enough they form an internode in between. Thus promote the growth of the plant.
They induce stem elongation, promote flowering, leaf expansion, seed germination etc.
Cytokinnins: The name comes from its ability to divide the cells. These participate in the growth of the plant by enhancing the cell multiplication. They increase the rate of cell division andmitosisin growing parts of the plant. Thus promote profuse tissue formation necessary for growth. It has anti-auxin, anti-gibberlin property. Helps in conservation ofwaterin plant during water deficiency.
Absicic acid: This hormone is a natural growth inhibitor. It has a role in some stage of plant growth like ripening of raw fruits etc. Thus they are involved in growth of plant to certain extent.
Ethylene:Ethylene is a gaseous phytohormone. It is also growth inhibitor like absicic acid. It is mainly involved in fruit maturation and ripening.
It also shows cell enlargement, geotropism i.e growing towards earth, fruit ripening etc
- Auxin
- Gibberlins
- Cytokines
- Absisic acid.
- Ethylene
Auxin; They have a prominent role in entire growth of plant. They guide the seedling during germination of plant from seed stage in such a way that roots go intosoilwhile stem moves up towards the sun. So auxin does it by phototropism (moving tolightfor stem) and geotropism (moving towardssoilfor roots) mechanism.
Further they promote plant elongation towards the sky and also towards the ground deeper by stem and roots respectively. This auxin is highly active in the tips of shoot (stem) and also root tip.
They induce cell elongation, inhibit falling of leaves and accelerate flower formation.
Gibberlin: These have a different role in promotinggrowth. They specially focus on elongating the nodes and also forming internodes. Nodes are those ridges or ring like structure seen on the stem of a bamboo, sugarcane etc. These gibberlins enhance elongation of a node and when the node is long enough they form an internode in between. Thus promote the growth of the plant.
They induce stem elongation, promote flowering, leaf expansion, seed germination etc.
Cytokinnins: The name comes from its ability to divide the cells. These participate in the growth of the plant by enhancing the cell multiplication. They increase the rate of cell division andmitosisin growing parts of the plant. Thus promote profuse tissue formation necessary for growth. It has anti-auxin, anti-gibberlin property. Helps in conservation ofwaterin plant during water deficiency.
Absicic acid: This hormone is a natural growth inhibitor. It has a role in some stage of plant growth like ripening of raw fruits etc. Thus they are involved in growth of plant to certain extent.
Ethylene:Ethylene is a gaseous phytohormone. It is also growth inhibitor like absicic acid. It is mainly involved in fruit maturation and ripening.
It also shows cell enlargement, geotropism i.e growing towards earth, fruit ripening etc
