Wang Xuxu, Qiu Gengcheng, Yang Jiading
Co-Innovation Center for Sustainable Forestry in Southern China, College of Life Sciences, Nanjing Forestry University, Nanjing 210037, China.
Int J Mol Sci. 2024 Dec 30;26(1):227. doi: 10.3390/ijms26010227.
The prerequisite for breeding a plant to be used in phytoremediation is its high tolerance to grow normally in soil contaminated by certain heavy metals. As mechanisms of plant uptake and transport of nickel (Ni) are not fully understood, it is of significance to utilize exogenous genes for improving plant Ni tolerance. In this study, from encoding an exporter of Ni and cobalt was overexpressed constitutively in , and the performance of transgenic plants was assayed under Ni stress. The subcellular localization of rcnA in plant cells was found to be the plasma membrane. Constitutive overexpression of in Arabidopsis rendered better growth of either seedlings on agar medium containing 85, 100, and 120 μM NiCl or adult plants in a nutrient solution with 5 mM NiCl added. Compared to the wildtype, -OE transgenic plants under Ni stress accumulated lower levels of reactive oxygen species (i.e., superoxide and hydrogen peroxide) in leaves and exhibited less oxidative damage in shoots, as demonstrated by less electrolyte leakage and the lower malondialdehyde content. Notably, -OE transgenic plants retained a higher content of Ni in roots and had a lower content of Ni in shoots. Therefore, our findings indicated that the bacterial gene may be utilized to improve plant Ni tolerance through genetic transformation.
培育用于植物修复的植物的前提条件是其在受某些重金属污染的土壤中具有高耐受性以正常生长。由于植物对镍（Ni）的吸收和转运机制尚未完全了解，利用外源基因提高植物对镍的耐受性具有重要意义。在本研究中，编码镍和钴输出蛋白的基因在拟南芥中组成型过表达，并在镍胁迫下检测转基因植物的表现。发现rcnA在植物细胞中的亚细胞定位是质膜。在拟南芥中组成型过表达该基因使得在含有85、100和120μM NiCl的琼脂培养基上的幼苗或添加了5 mM NiCl的营养液中的成年植物生长得更好。与野生型相比，镍胁迫下的rcnA过表达（rcnA -OE）转基因植物叶片中活性氧（即超氧化物和过氧化氢）的积累水平较低，并且地上部表现出较少的氧化损伤，这通过较少的电解质渗漏和较低的丙二醛含量得以证明。值得注意的是，rcnA -OE转基因植物根部的镍含量较高，而地上部的镍含量较低。因此，我们的研究结果表明，细菌rcnA基因可通过遗传转化用于提高植物对镍的耐受性。
