ObjectiveThe tolerance to salt stress, which is a major abiotic stress, is critical to plant survival and productivity. Remorins are plant-specific proteins and play an important role in plant adaptation to adverse environments. In this study, the gene PeREM1.3 coding for a remorin protein was cloned from Populus euphratica, and the role of PeREM1.3 in plant salt tolerance was investigated.

MethodThe gene constructs 35S::PeREM1.3 was transferred to model plant tobacco to investigate the function of PeREM1.3 in salt tolerance by physiological and biochemical methods.

ResultStudies showed that PeREM1.3 protein localized on the plasma membrane. The 600 bp full-length of open reading frame (ORF) of PeREM1.3 encoded a putative protein of 199 amino acids. The expression of PeREM1.3 was up-regulated under salt and osmotic stress in Populus euphratica. The results showed that the expression of PeREM1.3 increased the salt tolerance of tobacco. The activities of antioxidant enzymes such as SOD, POD and CAT significantly increased and decreased the ROS level to maintain ROS homeostasis in transgenic lines expressing PeREM1.3 under salt stress. On the other hand, the transcriptional levels of plant stress-resistance related genes, such as SOS1, HAK, NHA1, VAG1 and PMA4, were significantly increased and then maintained the K⁺/Na⁺ homeostasis in transgenic plants.

ConclusionThe above experimental data indicate that remorin protein could maintain ROS and K⁺/Na⁺ homeostasis and then enhance plant salt tolerance.