Brassinolide ameliorates adverse effects of salt stress on germination and seedling growth of rice

Rice in general is a salt sensitive crop. Seeds of two cultivars, viz. Kamini (salt susceptible) and Pusa 2–21 (salt tolerant) were allowed to germinate and grow in glass distilled water (control), 150 mM and 300 mM NaCl solutions, 4 μM brassinolide solution, 150 mM and 300 mM NaCl solutions supplemented with 4 μM brassinolide. Seed germination, seedling growth and hydrolytic enzymes (amylase and protease) associated with seedling development were adversely affected by NaCl salt stress. Reduction in DNA, RNA and soluble proteins and increase in peroxidase and free proline in rice seedlings were observed with increasing levels of salt stress. The effect was more conspicuous in Kamini than Pusa 2–21. Brassinolide, a steroidal component of plant origin was found to counter the adverse effect of salt stress irrespective of tolerant (kamini) and susceptible (Pusa 2–21) cultivars. Ameliorative effects of brassinolide were associated with increase in the levels of nucleic acids, soluble proteins, peroxidase and free proline content under salt stress.