Cadmium (Cd) is one of the major heavy metal pollutants in the environment and imposes severe limitations on crop growth and production. Glutathione (GSH) plays an important role in plant Cd tolerance which is able to scavenge stresses-induced reactive oxygen species (ROS) and is involved in the biosynthesis of phytochelatins (PCs). Our previous study revealed that Cd stress affects maize growth, and the GSH treatment could relieve Cd stress in maize seedlings. In this study, we attempted to characterize the metabolomics changes in maize leaves and roots under Cd stress and exogenous GSH conditions. We identified 145 and 133 metabolites in the leaves and roots, respectively. Cd stress decreased the tricarboxylic acid cycle (TCA cycle) metabolism and increased the amino acid contents in the leaves, while it decreased the amino acid contents, increased the TCA cycle metabolism, the sugar contents, and shikimic acid metabolism in the roots. On the other hand, exogenous GSH increased the GSH content, changed the production of metabolites related to antioxidant systems (such as ascorbic acid-related metabolites and flavonoid-related metabolites), and alleviated lipid peroxidation, thereby alleviating the toxic effect of Cd stress on maize. These findings support the idea that GSH alleviates Cd-induced stress in maize and may help to elucidate the mechanism governing Cd-induced stress and the GSH-driven alleviation effect.

中文翻译：

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代谢组学分析揭示了外源谷胱甘肽减轻玉米幼苗镉胁迫的机制

镉（Cd）是环境中的主要重金属污染物之一，对作物的生长和生产构成了严重的限制。谷胱甘肽（GSH）在植物对Cd的耐受性中起着重要作用，它能够清除胁迫诱导的活性氧（ROS），并参与植物螯合素（PCs）的生物合成。我们以前的研究表明，镉胁迫会影响玉米的生长，而谷胱甘肽处理可以缓解玉米幼苗中的镉胁迫。在这项研究中，我们试图表征在镉胁迫和外源谷胱甘肽条件下玉米叶片和根部的代谢组学变化。我们分别在叶和根中鉴定出145和133种代谢产物。镉胁迫降低了三羧酸循环（TCA循环）的代谢并增加了叶片中的氨基酸含量，同时降低了氨基酸含量，增加了根中的TCA循环代谢，糖含量和sh草酸代谢。另一方面，外源性谷胱甘肽增加了谷胱甘肽的含量，改变了与抗氧化剂系统相关的代谢产物（如抗坏血酸相关的代谢产物和类黄酮相关的代谢产物），并减轻了脂质过氧化反应，从而减轻了镉胁迫对Cd胁迫的毒性作用。玉米。这些发现支持了GSH减轻玉米中Cd诱导的胁迫的想法，并可能有助于阐明控制Cd诱导的胁迫的机制和GSH驱动的缓解作用。改变了与抗氧化剂系统相关的代谢产物（如抗坏血酸相关的代谢产物和类黄酮相关的代谢产物）的产生，并减轻了脂质过氧化作用，从而减轻了镉胁迫对玉米的毒性作用。这些发现支持了GSH减轻玉米中Cd诱导的胁迫的想法，并可能有助于阐明控制Cd诱导的胁迫的机理和GSH驱动的缓解作用。改变了与抗氧化剂系统相关的代谢产物（如抗坏血酸相关的代谢产物和类黄酮相关的代谢产物）的产生，并减轻了脂质过氧化作用，从而减轻了镉胁迫对玉米的毒性作用。这些发现支持了GSH减轻玉米中Cd诱导的胁迫的想法，并可能有助于阐明控制Cd诱导的胁迫的机制和GSH驱动的缓解作用。