Autophagy and Programmed Cell Death Are Critical Pathways in Jasmonic Acid Mediated Saline Stress Tolerance in Oryza sativa.

Saline stress is the most limiting condition impacting the plant growth, development, and productivity. In this present study, jasmonic acid (JA) was used as a foliar spray on the rice seedlings grown under saline stress. Increase in photosynthetic pigments, anthocyanin, and total protein content was observed with JA treatment while NaCl showed reduction in biochemical constituents and enhanced antioxidant enzyme activity. The leaf cells of NaCl-treated seedlings accumulated more ROS and had more fragmented nuclei, whereas JA decreased the accumulation and fragmentation during saline stress. In NaCl treatment, gene expression analysis showed many fold upregulation in comparison with other treatments. The results suggest that JA acts as a promoter for growth, physiological, biochemical, and cellular contents, as well as ameliorate the effects of saline stress. The expression of genes demonstrated that saline stress may promote autophagy, which leads to autophagic cell death, and improve tolerance to saline stress in rice seedlings via the jasmonic acid signaling pathway. However, the mechanism by which jasmonate signaling induces autophagy and cell death is unknown and requires further exploration.