水分胁迫下植物脯氨酸累积的分子机理

THE PLANT MOLECULAR MECHANISM OF PROLINE ACCUMULATION UNDER WATER STRESS

脯氨酸作为一种重要的渗透保护物质 ,在植物的抗性生理中发挥着重要的作用 .水分胁迫条件下 ,脯氨酸的累积通过 3种不同的途径进行 :效应细胞的从头合成 ;脯氨酸降解的减少以及脯氨酸转运系统的参与 . 1-吡咯啉 - 5 -羧酸合成酶 (P5CS)和脯氨酸脱氢酶 (ProDH)在脯氨酸合成和降解的过程中起着关键的调节作用 .总之 ,植物的脯氨酸合成、累积和代谢是一个受非生物胁迫和细胞内脯氨酸浓度高度调控的生理生化过程 .P5CS基因启动子分析表明 ,ABA可能参与了该基因的表达 .

Proline, as an important compatible osmolyte, as well as other functions, plays an important role under adverse conditions. Principally, accumulation of proline can be achieved in three different ways : de novo synthesis in the affected cells; decreased degradation; proline transportation system is also involved. 1-pyrroline-5-carboxylate synthetase(P5CS) and proline dehydrogenase(ProDH), play an crucial function in the synthesis and degradation of proline respectively. In all, De novo synthesis, catabolism and transport of proline are highly regulated by both abiotic stress and cellular proline concentration. ABA probably regulates the expression of P5CS gene due to the structure of the promoter of P5CS.