College of Architecture & Environment, Sichuan University, Chengdu, 610065, China.
College of Architecture & Environment, Sichuan University, Chengdu, 610065, China; State Key Laboratory of Hydraulics and Mountain River Engineering, Sichuan University, Chengdu, 610065, China.
Environ Pollut. 2019 Sep;252(Pt B):1791-1800. doi: 10.1016/j.envpol.2019.06.103. Epub 2019 Jun 26.
Phytochelatins (PCs) play a vital role in the tolerance and enrichment of cadmium (Cd) in higher plants by chelating with Cd. The aim of this study was to perform a full-scale metabolomics analysis of metabolic responses highly correlated with PCs generation. These metabolites and metabolic pathways were expected to promote PCs generation and further optimize Cd absorption in plants. In the current study, Amaranthus hypochondriacus, a potential species for phytoremediation, was first adopted to investigate physiological responses to Cd stress via LCMS/MS-based metabolomics and the HPLC based determination of thiol compounds. The results showed that the leaves of A. hypochondriacus under high Cd stress accumulated 40 times the amount of Cd compared to the leaves of the plants not under Cd stress and had an increased content of three types of PCs. Metabolomics qualitatively identified 12084 substances in total, among which 41 were significantly different metabolites (SDMs) between the two groups and involved in 7 metabolic pathways. Among the SDMs, 12 metabolites were highly linearly correlated with PCs involved in three pathways (Val, Leu and Ile biosynthesis; Ala, Asp and Glu metabolism; and Arg and Pro metabolism). These results provide an innovative method to promote PCs synthesis for the restoration of Cd-contaminated-soil.
植物螯合肽（PCs）通过与 Cd 螯合在高等植物耐受和富集 Cd 方面发挥着重要作用。本研究的目的是对与 PCs 生成高度相关的代谢反应进行全面的代谢组学分析。这些代谢物和代谢途径有望促进 PCs 的生成，并进一步优化植物对 Cd 的吸收。在本研究中，首次采用苋菜（Amaranthus hypochondriacus）作为一种有潜力的植物修复物种，通过基于 LCMS/MS 的代谢组学和基于 HPLC 的巯基化合物测定来研究对 Cd 胁迫的生理反应。结果表明，高 Cd 胁迫下的苋菜叶片中 Cd 的积累量是未受 Cd 胁迫叶片的 40 倍，且 PCs 的含量也有所增加。代谢组学总共定性鉴定出 12084 种物质，其中两组之间有 41 种差异显著的代谢物（SDMs），涉及 7 种代谢途径。在 SDMs 中，有 12 种代谢物与参与三条途径（缬氨酸、亮氨酸和异亮氨酸生物合成；丙氨酸、天冬氨酸和谷氨酸代谢；精氨酸和脯氨酸代谢）的 PCs 高度线性相关。这些结果为促进 PCs 合成以修复 Cd 污染土壤提供了一种创新方法。
