Methyl Jasmonate Pretreatment Promotes the Growth and Photosynthesis of Maize Seedlings under Saline Conditions by Enhancing the Antioxidant Defense System

摘要

Salinity could affected and give the stress for crop growth and development. Methyl jasmonate (MeJA) can mediate diverse developmental processes, but its specific role in plant salt tolerance is poorly understood. In order to identify the influence of MeJA under the salt tolerance in maize (Zea mays L.), plant growth， photosynthesis and antioxidant defense system were investigated. MeJA attenuated the crop development and oxidative damage caused by salt stress by generating less superoxide anion, hydrogen peroxide and malondialdehyde. Electrolyte leakage (EL), ascorbic acid (AsA), glutathione (GSH), hydrogen ascorbic acid type (DHA) and oxidized glutathione (GSSG), ratio of AsA/DHA and GSH/GSSG, were significantly reduced during seedling leaves. This is because MeJA maintained high SOD (Superoxide Dismutase), ascorbic acid peroxidase, glutathione reductase, monodehydroascorbate reductase and dehydroascorbate reductase activity under salt water. MeJA pretreatment ameliorated the adverse effect induced by salt stress on photosynthetic pigment content, photosynthetic capacity, and PSII photochemistry efficiency. The findings demonstrated that this promoted the development and photosynthesis of MeJA-treated maize seedlings under saline conditions by increasing the efficiency of the antioxidant defense system against oxidative damage.