植物对重金属锌耐性机理的研究进展

Zn是植物必需的营养元素,同时也是一种常见的有毒重金属元素.由于长期的环境选择和适应进化,植物相应对Zn~(2+)产生了耐性,可减轻或避免Zn~(2+)的毒害.植物对锌耐性机制有:菌根和细胞膜对Zn~(2+)吸收的阻止和控制,其中控制Zn~(2+)的细胞膜跨膜转运器主要有(ZIP)类、阳离子扩散促进器(CDF)类和B-type ATPase (HMA)类;金属硫蛋白(MTs)、植物螯合素(PCs)和有机酸等Zn~(2+)螯合物质的体内螯合解毒;体内区室化分隔以及通过抗氧化系统和渗透调节物质的代谢调节等.本文从生理和分子水平上综述了植物对Zn~(2+)耐性机理的研究进展,并在此基础上提出目前存在的问题和今后研究的重点领域,为该领域的相关研究提供资料和借鉴.

Research Progress in Mechanisms of Plant Tolerance to Zinc

Zinc (Zn) is not only an essential element for plant growth,but also a poisonous heavy metal element.Plant has developed some functions for Zn~(2+) tolerance.Mycorrhizae and cellular membranes are key factors that regulate Zn uptake.The trans-membrane transporters have been fully researched.Such as the ZIP (ZAT IRT related proteins) family,CDF (Cation diffusion facilitator) family and B-type ATPase(Heavy metal ATPase,HMA).The primary chelators of Zn in plants are metallothioneins(MTs),phytochelatins(PCs) and organic acids.They alleviate the toxity of zinc in plants by chelation.Intracellular sequestration and metabolic regulation by stimulating antioxidant systems and osmotic adjustment to minimize the damage from exposure to zinc stress.The article reviews recent advances in understanding the mechanisms of zinc tolerance in higher plants at the physiological and molecular level.Existing problems and major topics of future research were also discussed.