OsJAZ10 Modulates Metabolite Profiles in Rice Seedlings in Response to Alkaline Stress.

The jasmonate ZIM-domain (JAZ) proteins, known as inhibitors in the jasmonic acid (JA) pathway, have been reported to play a protective role against abiotic stress in plants. Nevertheless, the specific role of JAZ proteins in rice seedlings under alkaline stress remains unexplored. In this study, we mainly focus on OsJAZ10, investigating the physiological response mechanism and metabolic regulation on rice seedlings challenged by alkaline stress. Our results revealed that the antioxidant enzyme activity and osmotic adjustment ability of the OsJAZ10 overexpression lines were less affected by alkaline stress compared to WT (Wild-type) line. Metabolomic analysis demonstrated a significant accumulation of organic acids, including citrate and DL-malate, as well as amino acids such as DL-serine, DL-glutamine, threonine, glycine, and L-glutamate, in the OsJAZ10 overexpression plants in response to alkaline stress. Besides, OsJAZ10 was also involved in pantothenate and CoA biosynthesis, carbon fixation, and C5-branched dibasic acid metabolism in response to alkaline stress. Finally, OsJAZ10 was found to negatively regulated the biosynthesis and signaling of jasmonic acid pathway by repressing JA-responsive genes. Overall, this research elucidates the role of OsJAZ10 in conferring enhanced tolerance to alkaline stress in rice, providing valuable insights for the development of stress-tolerant rice varieties.