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Mn^(2+)吸收运输的转运蛋白或将Mn^(2+)分隔储存于内膜细胞器(如液泡)中,或在细胞内Mn^(2+)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Mn^(2+)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。
Manganese （Mn） is an essential micronutrient throughout all stages of plant development. Mn plays an important role in many metabolic processes 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 Ⅱ, and also function as a cofactor for a variety of enzymes, such as Mn-SOD. But excessive Mn is toxic to plants which is one of the most toxic metals in acid soils.
The knowledge of Mn^2＋ uptake and transport mechanisms, especially the genes responsible for transition metal transport, could facilitate the understanding of both Mn tolerance and toxicity in plants. Recently, several plant genes were identified to encode transporters with Mn^2＋ transport activity, such as zinc-regulated transporter/ironregulated 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 superoxide 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 identified as or proposed to be functioning in Mn^2＋ transport, Mn toxicity-induced oxidative stress, and the response of antioxidants and antioxidant enzymes in plants to excessive Mn to facilitate further study. Meanwhile, basing on our research results, new problems and views are brought forward.
出处
《植物生理与分子生物学学报》
CAS
CSCD
北大核心
2007年第6期480-488,共9页
Journal Of Plant Physiology and Molecular Biology
基金
国家自然科学基金项目(No.30671241)资助。
关键词
锰
转运蛋白
氧化胁迫
铝
manganese
transporter
oxidative stress
aluminum
