Plant Hormones : Are the growth regulators and important chemicals affecting growth of the plant.
–The growth regulators consists of :-
Four plant hormones are : -
1. Auxin :
Function :
1. Cell elongation and enlargement.
2. Apical dominance : The presence of terminal or apical bud results in the failure of lateral bud growth.
3. Parthenocarpy : Natural or artificial induced production of fruit without fertilization of ovule.
2. Gibberellins :
Function :
1. Cell Elongation.
2. Stem elongation : Induce stem elongation in genetically dwarf variety, called as Bolting effect.
3. Cytokinins :
Function :
1. Cell division.
2. Secondary growth : Cytokinins along with auxin promote secondary growth in plants that is increase thickness.
4. Ethylene :
Gaseous plant hormones .
–Autocatalytic in nature.
Function :
1. Fruit Ripening.
2. Accelerates the abscission of leaves and flowers.
