Studies on the heavy-metal tolerance and interactions between several metal-binding ligands in plants exposed to complex pollution conditions.

点击翻译按钮获取中文摘要

In the present studies, we examined the possible mechanisms for the heavy-metal tolerance and interactions with metal-binding ligands in plants exposed to complex conditions. We found(1) In tomato cells, phytochelatin (PC) formation and accumulation are involved in the expression of the heavy-metal tolerance characteristics. For the detoxification mechanism, required formation of the PC-complex can be strongly facilitated with Cd but inhibited by other elements such as Cu,As and B, which are not incorporated in the former PC-Cd complex.(2) Transports of Cd and As have been associated with the thiol peptides such as PCs and GSH in literatures. However, their transports can be significantly affected by organic acids and some inorganic such as borate. Under conditions where different metals and anions are mixed in medium, their transport rates from roots to shoots are very different (e.g. Cd and Zn are much faster than Cu or As, but in a manner which is correlated with some organic ligands).Here, borate facilitates the Cd transport but inhibits As transport to shoot.(3) Other major mono- and/or divalent metal ions reveal other unique mechanisms for transport and redistribution with ligands in plants, which taken together present new prospects in futurestudy.