There are many heavy metal stresses in agricultural biological systems, especially cadmium (Cd) stress, which prevent the full growth of plants, lead to a serious decline in crop yield, and endanger human health. Molybdenum (Mo), an essential nutrient element for plants, regulates plant growth mainly by reducing the absorption of heavy metals and protecting plants from oxidative damage. The aim of this study was to determine the protective effect of Mo (1 μM) application on wheat plants under conditions of Cd (10 μM) toxicity. The biomass, Cd and Mo contents, photosynthesis, leaf and root ultrastructure, antioxidant system, and active oxygen content of the wheat plants were determined. Mo increased the total chlorophyll content of wheat leaves by 43.02% and the net photosynthetic rate by 38.67%, and ameliorated the inhibitory effect of cadmium on photosynthesis by up-regulating photosynthesis-related genes and light-trapping genes. In addition, Mo reduced the content of superoxide anion (O) by 16.55% and 31.12%, malondialdehyde (MDA) by 20.75% and 7.17%, hydrogen peroxide (HO) by 24.69% and 8.17%, and electrolyte leakage (EL) by 27.59% and 16.82% in wheat leaves and roots, respectively, and enhanced the antioxidant system to reduce the burst of reactive oxygen species and alleviate the damage of Cd stress on wheat. According to the above results, Mo is considered a plant essential nutrient that enhances Cd tolerance in wheat by limiting the absorption, accumulation and transport of Cd and by regulating antioxidant defence mechanisms. Cadmium (Cd)，is one of the most toxic heavy metals in the environment, and Cd pollution is a global environmental problem that threatens food security and human health. Molybdenum (Mo), as an essential plant nutrient, is often used to resist environmental stress. However, the mechanism of Mo treatment on wheat subjected to Cd stress has not been reported. In this study, we systematically analysed the effects of Mo on the phenotype, physiology, biochemistry, ultrastructure and Cd content of wheat subjected to Cd stress, and comprehensively analysed the transcriptomics. It not only reveals the mechanism of Mo tolerance to Cd stress in wheat, but also provides new insights into phytoremediation and plant growth in Cd-contaminated soil.

中文翻译：

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从生理、生化和转录组学角度了解钼减轻小麦镉毒性的机制


农业生物系统中存在多种重金属胁迫，特别是镉（Cd）胁迫，阻碍植物充分生长，导致作物产量严重下降，危害人类健康。钼（Mo）是植物必需的营养元素，主要通过减少重金属的吸收、保护植物免受氧化损伤来调节植物生长。本研究的目的是确定在镉 (10 μM) 毒性条件下施用 Mo (1 μM) 对小麦植株的保护作用。测定了小麦植株的生物量、Cd和Mo含量、光合作用、叶和根超微结构、抗氧化系统和活性氧含量。钼使小麦叶片总叶绿素含量提高43.02%，净光合速率提高38.67%，并通过上调光合作用相关基因和诱光基因改善镉对光合作用的抑制作用。此外，Mo还使超氧阴离子（O）含量降低16.55%和31.12%，丙二醛（MDA）含量降低20.75%和7.17%，过氧化氢（H2O）含量降低24.69%和8.17%，电解液泄漏（EL）降低小麦叶片和根部的含量分别为27.59%和16.82%，增强了抗氧化系统，减少了活性氧的爆发，减轻了镉胁迫对小麦的损害。根据上述结果，Mo被认为是植物必需营养素，通过限制Cd的吸收、积累和转运以及调节抗氧化防御机制来增强小麦的Cd耐受性。镉（Cd），是环境中毒性最强的重金属之一，镉污染是威胁粮食安全和人类健康的全球性环境问题。 钼（Mo）作为植物必需的营养素，常被用来抵抗环境胁迫。然而Mo处理对Cd胁迫小麦的作用机制尚未见报道。本研究系统分析了Mo对Cd胁迫下小麦表型、生理生化、超微结构和Cd含量的影响，并进行了转录组学的综合分析。它不仅揭示了小麦Mo对Cd胁迫的耐受机制，而且为Cd污染土壤的植物修复和植物生长提供了新的见解。