Brassinosteroids ppt

brassinosteroids as plant harmone

1. Brassinosteroids Presented by- S ayali U nmesh K elkar . Regd. No. - 2425

2. Introduction Occurrence- - 40 years ago - Mitchel et. al. - Brassinolid

3. Structure

4. Biosynthesis - starting from compestrol - precursor- teasterone Site of synthesis- Acropetal flow- Recognized at cell membrane-

5. Harmonal activity Works with auxin - cell expansion and elongation. BR’s signal transduction has been studied during vascular differentiation. For pollen tube formation. Delay senescence. Protect against chilling and drought. Help to counteract stress. Promote apical dominance. Increase resistance to freezing.

6. Harmonal activity Inhibit root growth. Enhanance seed germination. Increase production of ethylene. Prevent p remature abscission of fruit.

7. Applications Application to cucumber increase metabolism and removes pesticide residue. 28-homoBL is most effective- increase tolerance to high temp. Effective when applied to rice. 24-epiBL have protective role on shoot,root length, also on soluble protein, proline content, and perioxidase . Help to overcome unfavourable cultural and environmental conditions.

8. Applications Also used in horticultural crops. Help to bridge the gap between consumers health concerns and the producers need for growth. Does not contribute to co-evolution of pest. Also used in tissue cultures, in cell enlargement. It was reported that BR’s at low conc acted as inhibitor of growth of Agrobacterium tumefaciens .