【摘要】 为探究外源有机酸在加强秋华柳（Salix variegata Franch.）镉积累效率中的应用潜力,采用营养液培养方法,研究了5种100μmol/L外源有机酸（草酸、柠檬酸、酒石酸、苹果酸和琥珀酸）对50μmol/L Cd胁迫下秋华柳生长适应性及Cd积累特征的影响,并通过化学平衡程序VISUAL MINTEQ v3.0计算溶液中不同化学形态Cd（游离态和螯合态Cd）的含量。结果表明:柠檬酸、酒石酸、苹果酸和琥珀酸的添加有效缓解了Cd对秋华柳的毒害,明显促进了秋华柳的生长。除草酸处理组外,其余4个有机酸处理组培养液中游离Cd²⁺含量均得到较大提升,显著促进了秋华柳对Cd的吸收。柠檬酸、酒石酸、琥珀酸和苹果酸的添加显著提高了秋华柳植株的Cd积累量,分别是未加入有机酸Cd处理组的210%、190%、190%和178%。外源有机酸的施加提高了介质中游离Cd²⁺的含量,并通过与重金属的络合等作用提升了植株对Cd的吸收和积累能力。但不同有机酸对秋华柳Cd积累特征的影响差异明显,柠檬酸加入后通过提高秋华柳根生物量和根中Cd含量,显著增加了根系Cd积累量;酒石酸、苹果酸和琥珀酸的应用则明显提高了秋华柳地上部分Cd积累量。因此,外源酒石酸、琥珀酸和苹果酸的应用可提高秋华柳地上部分的Cd积累效率,更有利于对Cd污染土壤的修复。更多还原

【Abstract】 Cadmium（Cd） is characterized as being highly toxic to human health, and its accumulation in plants may exert a health risk for humans through food chain. Phytoextraction is a way for plants to transfer heavy metals from soils to the harvestable parts, which is considered to be an environment-friendly and inexpensive technology for the remediation of metal-contaminated soils. Chelate-induced phytoextraction reduced by organic acids can be used to enhance metal uptake and translocation in plants. To explore the application potential of exogenous organic acids in accelerating Cd accumulation efficiency in Salix variegata Franch., a nutrient culture experiment was conducted to detect the effects of five exogenous organic acids（oxalic acid, citric acid, tartaric acid, malic acid, and succinic acid） with the concentration of 100 μmol/Lon the growth adaptability and Cd accumulation of S. variegata under 50 μmol/L Cd stress. The contents of different Cd speciation（free and chelated Cd） in the solution were calculated by the chemical equilibrium program VISUAL MINTEQ v3.0.The results showed that the addition of citric acid, tartaric acid, malic acid, and succinic acid effectively alleviated the toxicity of Cd stress on S. variegata, and significantly improved its growth. Except for the oxalic acid-treated group, the free Cd²⁺ was greatly increased, which significantly promoted the absorption of Cd in S. variegata. The addition of citric acid, tartaric acid, malic acid, and succinic acid significantly increased Cd accumulation rates in S. variegata plants, which were 210%, 190%, 178%, and 190%, respectively compared with that of the CK group. The application of exogenous organic acid increased the content of free Cd²⁺ in the culture and enhanced the ability of plants to absorb and accumulate Cd through complexation with heavy metals. However, the effects of different organic acids on the Cd accumulation characteristics of S. variegata were obvious. The addition of citric acid increased the root biomass and Cd content of roots significantly, whereas the application of tartaric acid, malic acid, and succinic acid increased aboveground Cd accumulation of S. variegata. In summary, the application of exogenous tartaric acid, succinic acid, and malic acid can improve the Cd accumulation efficiency of the aboveground parts of S. variegata, which will be beneficial to the phytoremediation of Cd-contaminated soil.更多还原