State Key Lab of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, No. 73, Huanghe Road, Nangang District, Harbin 150090, People's Republic of China.
State Key Lab of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, No. 73, Huanghe Road, Nangang District, Harbin 150090, People's Republic of China.
J Hazard Mater. 2023 Oct 5;459:132075. doi: 10.1016/j.jhazmat.2023.132075. Epub 2023 Jul 17.
Salt interference significantly affects the behavior of heavy metals in the environment. This study compared and analyzed the response process, migration, and transformation of cadmium (Cd) in the hyperaccumulator Solanum nigrum (S. nigrum) under different NaCl levels to reveal the interference mechanisms of salt in plant remediation of Cd-contaminated soil. The results showed that Cd and salt stress significantly inhibited the growth of plants. The stress effect had more potent growth inhibition at the root than aboveground, thus inducing changes in the spatial configuration of the plants (decreased root-to-aboveground biomass ratio). Salt could activate Cd in plants, enhancing the inhibitory effect on plant growth. Salt increased Cd bioavailability due to the rhizosphere acidification effect, increasing plants' Cd accumulation. The Cd bioconcentration factor in plant roots peaked during the high Cd-high salt treatment (117.10), but the Cd accumulation of plants peaked during the high Cd-low salt treatment (233.04 μg plant). Salt additions and increased Cd concentrations enhanced root compartmentalization, inhibiting Cd transport to the aboveground. Changes in Fourier-transform infrared spectroscopy (FTIR) measurements confirmed that the functional groups in plants provided binding sites for Cd. These findings can help guide the phytoremediation of Cd contamination under saline soil conditions.
盐度干扰显著影响环境中重金属的行为。本研究比较和分析了不同 NaCl 水平下超富集植物龙葵（S. nigrum）中镉（Cd）的响应过程、迁移和转化，揭示了盐在植物修复 Cd 污染土壤中的干扰机制。结果表明，Cd 和盐胁迫显著抑制了植物的生长。胁迫效应在根部比地上部更强烈地抑制生长，从而诱导植物空间构型的变化（降低根冠比）。盐可以激活植物中的 Cd，增强对植物生长的抑制作用。由于根际酸化作用，盐增加了 Cd 的生物利用度，增加了植物对 Cd 的积累。在高 Cd-高盐处理下，植物根部的 Cd 生物浓缩因子达到峰值（117.10），但在高 Cd-低盐处理下，植物的 Cd 积累达到峰值（233.04μg 植物）。盐的添加和 Cd 浓度的增加增强了根区的分区化，抑制了 Cd 向地上部的运输。傅里叶变换红外光谱（FTIR）测量的变化证实，植物中的功能基团为 Cd 提供了结合位点。这些发现可以帮助指导盐渍土条件下 Cd 污染的植物修复。
