Expression of lhcb3 and cao gene and transformation of phosphorylation State of Thylakoid in Dunaliella salina under salt-stress condition

Abstract

LHC II plays important roles in many processes, such as absorption and transmission of light, maintenance of thylakoid membrance structure, regulation of excitation energy distribution between two optical systems, light protection and adaptation of various environmental protection. In this study, the real-time PCR and protein gel electrophoresis technique were used to study the expression of lhcb3 and chlorophyll a oxygenase gene cao of Dunaliella salina under low-salt stress condition, and the changes of thylakoid membrane phosphorylation and phospholipase. The results showed that under low-salt stress condition, the expression activity of lhcb3 and gene cao decreased, which might result from the adaption responses of D. salina to different concentrations of salt. Phosphorylation of thylakoid membrane protein decreased initially, and increased afterwards. In the mean time, the change of phosphatase had same trend and the peak appeared after 12 h treatment. This study suggested that, under low-salt condition, a lower level of thylakoid membrane protein phosphorylation resulted from decrease of phosphatase activity at the beginning of the treatment. However, after 12 h treatment, in return because of the intracellular homeostasis, the activity of kinase increased, which resulted in the enhancement of phosphorylation eventually.