Abstract: The concentration dependence and time course of selenium (Se) absorption and accumulation in tea plant were investigated under sand culture and the expressions of related genes were also analyzed. The results show that the absorption amounts of Se in different tissues of tea plant were remarkably different. Most of them were fixed by the roots, and low movement from roots to shoots was observed. Moreover, the accumulation of Se was significantly correlated with exogenous Se concentration and culture duration. Furthermore, tea plant grew well in the Se concentration from 0 to 0.05 mmol·L^-1, but when the concentration was higher than 0.10 mmol·L^-1, tea plant showed poisoning symptoms. Fluorescence quantitative PCR analysis indicates that allene oxide cyclase (CsAOC), lipoxygenase (CsLOX6) (key genes of jasmonic acid signaling pathway), as well as a basic helix-loop-helix transcription factor (CsbHLH62) could be obviously induced by high concentration of Se. The correlation analysis showes that the expressions of these genes were positively related with the Se content in roots. These results suggest that Se accumulation in different tissues of tea plant was significantly correlated with exogenous Se concentration and culture duration, and CsbHLH62, CsAOC, CsLOX6 might play important roles in this process.

Key words: tea plant, Se, absorption and accumulation, gene expression