【摘要】 锰（Mn）毒是酸性土壤上限制作物生长的重要因素。植物体内Mn²⁺吸收运输的转运蛋白或将Mn²⁺分隔储存于内膜细胞器（如液泡）中,或在细胞内Mn²⁺运输及调节中起重要作用。近年,编码这些转运蛋白的基因已被分离鉴定。另外,高Mn胁迫极易诱导植物产生氧化胁迫,抗氧化系统在清除高Mn胁迫诱导产生的活性氧过程中起到重要作用。文章重点就承担Mn²⁺跨膜运输的膜转运蛋白以及植物抗氧化系统对高Mn胁迫的响应两方面进行了综述,并结合作者的研究提出看法和展望。更多还原

【Abstract】 Manganese （Mn） is an essential micro- nutrient throughout all stages of plant development. Mn plays an important role in many metabolic pro- cesses in plants.It is of particular importance to photosynthetic organisms in the chloroplast of which a cluster of Mn atoms at the catalytic centre function in the light-induced water oxidation by photosystem H,and also function as a cofactor for a variety of enzymes,such as Mn-SOD.But ex- cessive Mn is toxic to plants which is one of the most toxic metals in acid soils. The knowledge of Mn2+ uptake and transport mechanisms,especially the genes responsible for transition metal transport,could facilitate the un- derstanding of both Mn tolerance and toxicity in plants.Recently,several plant genes were identi- fied to encode transporters with Mn2 transport activity,such as zinc-regulated transporter/iron- regulated transporter （ZRT/IRT1）-related protein （ZIP） transporters,natural resistance-associated macrophage protein （Nramp） transporters,cation/ H⁺ antiporters,the cation diffusion facilitator （CDF） transporter family,and P-type ATPase. In addition,excessive Mn frequently induces oxidative stress,then several defense enzymes and antioxidants are stimulated to scavenge the super- oxide and hydrogen peroxide formed under stress. Mn-induced oxidative stress and anti-oxidative reaction are very important mechanisms of Mn toxicity and Mn tolerance respectively in plants. This article reviewed the transporters identi- fied as or proposed to be functioning in Mn²⁺ transport,Mn toxicity-induced oxidative stress,and the response of antioxidants and antioxidant en- zymes in plants to excessive Mn to facilitate fur- ther study.Meanwhile,basing on our research results,new problems and views are brought forward.更多还原