Arsenic, cadmium, lead, and mercury are toxic elements that are almost ubiquitously present at low levels in the environment because of anthropogenic influences. Dietary intake of plant-derived food represents a major fraction of potentially health-threatening human exposure, especially to arsenic and cadmium. In the interest of better food safety, it is important to reduce toxic element accumulation in crops. A molecular understanding of the pathways responsible for this accumulation can enable the development of crop varieties with strongly reduced concentrations of toxic elements in their edible parts. Such understanding is rapidly progressing for arsenic and cadmium but is in its infancy for lead and mercury. Basic discoveries have been made in Arabidopsis, rice, and other models, and most advances in crops have been made in rice. Proteins mediating the uptake of arsenic and cadmium have been identified, and the speciation and biotransformations of arsenic are now understood. Factors controlling the efficiency of root-to-shoot translocation and the partitioning of toxic elements through the rice node have also been identified.

中文翻译：

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农作物和食物中有毒重金属和类金属的积累

砷、镉、铅和汞是有毒元素，由于人为影响，它们在环境中几乎无处不在，含量很低。植物性食物的膳食摄入占潜在威胁健康的人类暴露的主要部分，尤其是砷和镉。为了更好的食品安全，减少作物中有毒元素的积累非常重要。对导致这种积累的途径的分子理解可以使作物品种的可食用部分有毒元素浓度大大降低。这种对砷和镉的理解正在迅速发展，但对铅和汞的理解尚处于起步阶段。在拟南芥、水稻等模型中已经有了基本的发现，农作物的大部分进步都是在水稻中取得的。介导砷和镉吸收的蛋白质已被鉴定，并且砷的物种形成和生物转化现在已被了解。还确定了控制根到茎易位效率和有毒元素通过水稻节点分配的因素。