摘要
砷作为一种典型有毒元素被认为是最为严重的污染物之一。砷元素对人体的危害是一个长期的、慢性的毒害过程。水稻对砷的同化吸收能力高于其他谷物,稻米是人体摄入砷的主要来源之一。水稻籽粒中砷以无机As（Ⅲ＋Ⅴ）、二甲基砷（DMA）为主,其中无机砷占总砷的10%～90%。大米中总砷含量为0.005～0.710mg/kg。研究发现含砷大米可以分为两种不同类型：一类是大米中砷以DMA为主,且DMA含量随总砷含量的增加而增加;另一类是大米中砷以无机As（Ⅲ＋Ⅴ）为主,含量也随总砷含量的增加而增加。淹水厌氧环境是造成水稻砷富集的主要原因之一。在土壤富氧条件下种植水稻可有效减少水稻对砷的吸收。砷元素在水稻根际环境中的行为研究、微生物调控作用研究、水稻体内砷代谢机制的分子生物学及功能基因组研究等对未来水稻中砷的研究有着重要指导意义。
Arsenic（As） is now regarded as one of the most serious contaminants as a typical noxious element,especially inorganic arsenic. Indeed, arsenic has a chronic poisoning effect in human body. Recent studies have shown that rice is much more efficient in assimilating arsenic into its straw and grains than other staple cereal crops, and consumption of rice constitutes a large proportion of dietary intake of arsenic. Therefore, scientists pay a high degree of attention to arsenic in rice. In rice total As content varies from 0.005 to 0.710 mg/kg. Arsenic speciation in rice grain is dominated by inorganic As（Ⅲ＋V） and dimethylarsinic（DMA）. The inorganic As content in rice varies from 10% to 90% of total As. Now, studies have shown that there are two types of arsenic contained rice, one with arsenic speciation dominated by DMA, and the other by inorganic arsenic. Both of them show an increasing trend in DMA/As（Ⅲ＋V） content with rising total arsenic. The flooded conditions is one of the main reasons for enhanced arsenic accumulation in rice, and growing rice aerobically can dramatically decrease the arsenic transfer from soil to rice. Differing chemical states of arsenic, the mechanism of arsenic mobility in rhizosphere and mediated by microbial activity is need to be further researched in the near future. In addition, molecular approaches and functional genomics may also help understand the mechanisms of arsenic transportation and transform in rice.
出处
《中国水稻科学》
CAS
CSCD
北大核心
2010年第3期329-334,共6页
Chinese Journal of Rice Science
基金
上海市优秀学科带头人资助项目(07XD14010)
上海市科学技术委员会资助项目(08DZ1207900)
关键词
稻米
砷
毒害
rice
arsenic
toxicity
作者简介
王永杰（1979-），男，博士研究生。
通讯联系人：E—mail：xmzheng@re．ecnu．edu．cn
