Mitigation of Salt Stress by Foliar Application of Proline in Rice

A pot experiment was conducted at Bangladesh Agricultural University to evaluating the effect of exogenous application of proline on the growth and yield of rice under salt stress condition. There were six treatments including T1 (Control), T2 (25 mM NaCl), T3 (50 mM NaCl), T4 (25 mM NaCl + Proline), T5 (50 mM NaCl + Proline) and T6 (Proline). A salt sensitive variety of rice (cv. BRRI dhan29) was used as a test crop. Salinity (NaCl) was induced at vegetative growth stage (35 days after transplanting) of rice. Proline of 25 mL plant-1 was applied as foliar on the same day of NaCl treatment. All plants virtually died when they were treated with 50 mM NaCl (T3). On the other hand, foliar application of proline resulted in a significant increase in plant growth parameters of rice. The grain and straw yields plant-1 decreased with increased salinity levels. When the salt treated plants were supplied with exogenous proline, they produced significant amount of grain and straw yields. Sodium content and uptake by plants were decreased with foliar application of proline. It can be concluded that salt stress in rice reduce to a significant extent due to the exogenous application of proline.