1+1<2: Combined effect of low temperature stress and salt stress on Sesuvium portulacastrum L.

To expedite the deployment of Sesuvium portulacastrum floating bed technology in Hangzhou Bay and the Yangtze River Estuary, and to overcome the cryogenic constraint, our study concentrated on investigating the impacts of both individual and combined stress factors, particularly low temperature and salinity, on its application. We detected the S. portulacastrum related enzyme activity and other biological macromolecules under low temperature stress, salt stress and combined stress. And we also analyzed the stress resistance mechanism under different stress conditions by transcriptomic technology. It was discovered that moderate salt stress could enhance plant tolerance to low temperature, indicating the presence of an antagonistic relationship between salinity and low temperature. The biological mechanism underlying this phenomenon lies in the fact that combined stresses induce the up-regulation of various genes and activate more pathways compared to single stress. Among these pathways, the linoleic acid metabolic pathway stands out as unique to combined stress conditions. This research represents the inaugural endeavor to investigate the impact of low temperature stress and combined stress on S.portulacastrum, offering a pivotal reference for the utilization of this plant in ecological restoration and management within the East China Sea. More valuable is that such conclusions may be extended to the coastal ecological governance of many high latitude countries, which is of great significance for global ecological environment improvement.