Departamento de Bioquímica, Biología Cellular y Molecular de Plantas, Estación Experimental del Zaidín, CSIC, Prof. Albareda No. 1, Granada 18008, Spain.
Environ Sci Pollut Res Int. 2013 Apr;20(4):2150-61. doi: 10.1007/s11356-013-1485-4. Epub 2013 Jan 22.
Lead (Pb) is naturally occurring element whose distribution in the environment occurs because of its extensive use in paints, petrol, explosives, sludge, and industrial wastes. In plants, Pb uptake and translocation occurs, causing toxic effects resulting in decrease of biomass production. Commonly plants may prevent the toxic effect of heavy metals by induction of various celular mechanisms such as adsorption to the cell wall, compartmentation in vacuoles, enhancement of the active efflux, or induction of higher levels of metal chelates like a protein complex (metallothioneins and phytochelatins), organic (citrates), and inorganic (sulphides) complexes. Phyotochelains (PC) are synthesized from glutathione (GSH) and such synthesis is due to transpeptidation of γ-glutamyl cysteinyl dipeptides from GSH by the action of a constitutively present enzyme, PC synthase. Phytochelatin binds to Pb ions leading to sequestration of Pb ions in plants and thus serves as an important component of the detoxification mechanism in plants. At cellular level, Pb induces accumulation of reactive oxygen species (ROS), as a result of imbalanced ROS production and ROS scavenging processes by imposing oxidative stress. ROS include superoxide radical (O2(.-)), hydrogen peroxide (H2O2) and hydroxyl radical ((·)OH), which are necessary for the correct functioning of plants; however, in excess they caused damage to biomolecules, such as membrane lipids, proteins, and nucleic acids among others. To limit the detrimental impact of Pb, efficient strategies like phytoremediation are required. In this review, it will discuss recent advancement and potential application of plants for lead removal from the environment.
铅（Pb）是一种自然存在的元素，由于其在油漆、汽油、炸药、污泥和工业废物中的广泛应用，其在环境中的分布是不可避免的。在植物中，Pb 的吸收和转运会发生，导致有毒效应，从而减少生物量的产生。通常，植物可以通过诱导各种细胞机制来防止重金属的毒性作用，例如吸附到细胞壁上、区室化到液泡中、增强主动外排、或诱导更高水平的金属螯合物，如蛋白质复合物（金属硫蛋白和植物螯合肽）、有机（柠檬酸）和无机（硫化物）复合物。植物螯合肽（PC）是由谷胱甘肽（GSH）合成的，这种合成是由于 GSH 中的 γ-谷氨酰半胱氨酸二肽通过一种组成型存在的酶 PC 合成酶的转肽作用而产生的。植物螯合肽与 Pb 离子结合，导致 Pb 离子在植物中被隔离，从而成为植物解毒机制的重要组成部分。在细胞水平上，Pb 通过产生不平衡的 ROS 产生和 ROS 清除过程来诱导活性氧物质（ROS）的积累，从而导致氧化应激。ROS 包括超氧自由基（O2(-.)）、过氧化氢（H2O2）和羟基自由基（(·)OH），它们是植物正常功能所必需的；然而，过量的 ROS 会对生物分子造成损害，如膜脂质、蛋白质和核酸等。为了限制 Pb 的有害影响，需要采用有效的策略，如植物修复。在这篇综述中，将讨论植物从环境中去除 Pb 的最新进展和潜在应用。
