Liu Chengfeng, Yi Lita, Ge Zhiwei, Liu Meihua
National Key Laboratory for Development and Utilization of Forest Food Resources, Zhejiang A & F University, Hangzhou 311300, China.
Co-Innovation Center for Sustainable Forestry in Southern China, College of Ecology and Environment, Nanjing Forestry University, Nanjing 210037, China.
Metallomics. 2025 Aug 5;17(8). doi: 10.1093/mtomcs/mfaf027.
The extensive contamination of terrestrial ecosystems with multiple potentially toxic elements (PTEs) necessitates elucidation of plant adaptive mechanisms under combined PTEs stress. This study examines the physiological adaptations, antioxidant regulation, and PTEs allocation patterns in Cunninghamia lanceolata seedlings exposed to lead (Pb) stress (Pb4, 4.0 mg kg-1 Pb; Pb40, 40 mg kg-1 Pb), cadmium (Cd) stress (Cd2, 2 mg kg-1 Cd; Cd20, 20 mg kg-1 Cd), and combined Pb and Cd stress. Results demonstrated concentration-dependent inhibition of biomass production and chlorophyll b biosynthesis under both single and combined PTEs stress conditions. Different responses in superoxide dismutase activity were observed under combined stress compared to the controls, with lower concentration Pb stress causing notably higher enzymatic activation compared to higher concentration Pb stress. Elevated Cd concentrations resulted in significant accumulation of malondialdehyde in leaf tissues, indicating membrane damage. Lead preferentially accumulated in leaves under single Pb stress, while Cd predominantly accumulated in root systems. However, when the plants were exposed to combined Pb and Cd stress, the PTEs translocation pathways in the plants were altered, which resulted in a greater retention of Cd in the stems compared to when the plants were exposed to the single PTE stress. These findings provide insights into species-specific PTE homeostasis mechanisms under polymetallic stress, thereby providing theoretical foundations for the development of phytoremediation strategies in environments contaminated with multiple PTEs.
陆地生态系统受到多种潜在有毒元素（PTEs）的广泛污染，因此有必要阐明植物在复合PTEs胁迫下的适应机制。本研究考察了遭受铅（Pb）胁迫（Pb4，4.0 mg kg-1 Pb；Pb40，40 mg kg-1 Pb）、镉（Cd）胁迫（Cd2，2 mg kg-1 Cd；Cd20，20 mg kg-1 Cd）以及铅镉复合胁迫的杉木幼苗的生理适应、抗氧化调节和PTEs分配模式。结果表明，在单一和复合PTEs胁迫条件下，生物量生产和叶绿素b生物合成均受到浓度依赖性抑制。与对照相比，复合胁迫下超氧化物歧化酶活性呈现不同反应，低浓度Pb胁迫比高浓度Pb胁迫引起的酶活性显著更高。Cd浓度升高导致叶片组织中丙二醛大量积累，表明膜受到损伤。单一Pb胁迫下，Pb优先积累在叶片中，而Cd主要积累在根系中。然而，当植物受到铅镉复合胁迫时，植物体内PTEs的转运途径发生改变，与单一PTE胁迫相比，茎中Cd的滞留量更大。这些发现为多金属胁迫下特定物种的PTE内稳态机制提供了见解，从而为受多种PTEs污染环境中植物修复策略的制定提供了理论基础。
