Comparative physiological and proteomic analyses of mangrove plant Kandelia obovata under cold stress.

Cold events had broadly affected the survival and geographic distribution of mangrove plants. Kandelia obovata, has an excellent cold tolerance as a true halophyte and widespread mangrove species. In this study, physiological characters and comparative proteomics of leaves of K. obovata were performed under cold treatment. The physiological analysis showed that K. obovata could alleviate its cold-stress injuries through increasing the levels of antioxidants, the activities of related enzymes, as well as osmotic regulation substances (proline). It was detected 184 differentially expressed protein spots, and of 129 (70.11%) spots were identified. These proteins have been involved in several pathways such as the stress and defense, photosynthesis and photorespiration, signal transduction, transcription factors, protein biosynthesis and degradation, molecular chaperones, ATP synthesis, the tricarboxylic acid (TCA) cycle and primary metabolisms. The protein post-translational modification may be a common phenomenon and plays a key role in cold-response process in K. obovata. According to our precious work, a schematic diagram was drawn for the resistance or adaptation strategy of mangrove plants under cold stress. This study provided valuable information to understand the mechanism of cold tolerance of K. obovata.