Effect of salinity and alleviating role of methyl jasmonate in some rice varieties

Abstract

Background and Objective: Methyl jasmonate (MeJA) is involved in signal transduction pathway of plant development and responses to several environmental stress factors. This study was undertaken to explore the role of exogenous methyl jasmonate (MeJA) for mitigation of salt stress effect of six rice varieties. Materials and Methods: Two hybrid (BRRI dhan31 and BRRI dhan46) and four local (Gota, Kajalsail, Pokkali and Pengek) rice varieties were selected. Seedlings were grown hydroponically with normal conditions until 21 days and then subjected to 9 dS m-1 NaCl stress followed by application of 10 or 20 μM MeJA as foliar spray. Changes in biochemical components such as activity of antioxidant enzymes i.e., catalase (CAT), peroxidase (POD), ascorbate peroxidase (APX), chlorophyll content, Na+ and K+ contents of 28 days seedling stage were assayed. Results: The MeJA significantly increased plant growth, chlorophyll and K+ content which were reduced by the application of NaCl while reduced Na+ content in local varieties that was increased upon NaCl stress. Both NaCl stress as well as MeJA had varying trend in CAT activity while NaCl stress induced a significant increase in POD and APX activity but MeJA induced varying trend in different varieties. This study revealed that visual plant growth, chlorophyll, Na+ and K+ content support the positive effect of MeJA on mitigation of salt stress. Conclusion: The MeJA could be effectively sprayed on rice variety in saline belts as 10 μM MeJA adequately proved its salinity alleviating role.