Tianjin Key Laboratory of Animal and Plant Resistance, College of Life Sciences, Tianjin Normal University, China.
Tianjin Key Laboratory of Animal and Plant Resistance, College of Life Sciences, Tianjin Normal University, China.
Plant Sci. 2022 Jun;319:111252. doi: 10.1016/j.plantsci.2022.111252. Epub 2022 Mar 14.
Zrt and Irt-like proteins (ZIPs) are responsible for transporting various divalent metal cations. However, information about the characteristics of the cellular and physiological tolerance of plant ZIPs to Cd stress is still limited. The expression levels of SmZIP8 in Salix matsudana Koidz were upregulated by Cd stress. The complete length of SmZIP8 from S. matsudana was cloned, and transgenic tobacco was obtained by Agrobacterium-mediated transformation. Then, the tolerance to Cd stress of wild-type (WT) and transgenic tobacco seedlings was analyzed and compared by studying the cytotoxicity of the root tip cells, photosynthetic parameters, histochemical staining of O and HO, the activities of antioxidant enzymes, and malondialdehyde content under Cd stress. In comparison with WT tobacco, the ectopic expression of SmZIP8 in tobacco promoted the cytological tolerance of the transgenic tobacco to Cd stress by reducing cell damage, raising the mitotic indexes, and reducing the rate of chromosome aberration of the root cells. Meanwhile, the results of increased photosynthetic capacity, decreased oxidative damage, and activated antioxidant enzymes showed that the physiological tolerance of transgenic tobacco to Cd was enhanced. The principal component analysis for the above physiological parameters explained 96.08% of the total variance (PC1, 77.77%; PC2, 18.31%), indicating a significant difference in Cd tolerance abilities between the tobacco expressing SmZIP8 and WT tobacco. Therefore, SmZIP8 may be considered as an important genetic resource for the phytoremediation of Cd or other heavy metal pollution via the use of transgenic plants obtained through genetic transformation.
Zrt 和 Irt 样蛋白（ZIPs）负责运输各种二价金属阳离子。然而，关于植物 ZIP 对 Cd 胁迫的细胞和生理耐受特性的信息仍然有限。镉胁迫下，柳属 SmZIP8 的表达水平上调。克隆了来自柳属的 SmZIP8 的全长，并通过农杆菌介导的转化获得了转基因烟草。然后，通过研究根尖细胞的细胞毒性、光合参数、O 和 HO 的组织化学染色、抗氧化酶活性和 MDA 含量，分析和比较了野生型（WT）和转基因烟草幼苗对 Cd 胁迫的耐受性。与 WT 烟草相比，SmZIP8 在烟草中的异位表达通过减少细胞损伤、提高有丝分裂指数和降低根细胞染色体畸变率，促进了转基因烟草对 Cd 胁迫的细胞学耐受性。同时，增加的光合能力、降低的氧化损伤和激活的抗氧化酶的结果表明，转基因烟草对 Cd 的生理耐受性增强。上述生理参数的主成分分析解释了总方差的 96.08%（PC1，77.77%；PC2，18.31%），表明表达 SmZIP8 的烟草和 WT 烟草之间在 Cd 耐受能力上存在显著差异。因此，SmZIP8 可以被认为是通过遗传转化获得的转基因植物进行 Cd 或其他重金属污染植物修复的重要遗传资源。
