Zhang Songlin, Chen Hongchun, He Danni, He Xinrui, Yan Ya, Wu Kejun, Wei Hong
Key Laboratory of Eco-environments in Three Gorges Reservoir Region (Ministry of Education), Chongqing Key Laboratory of Plant Ecology and Resources Research in Three Gorges Reservoir Region, School of Life Sciences, Southwest University, Chongqing, China.
Key Laboratory of Reservoir Aquatic Environment, Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing, China.
Front Plant Sci. 2020 Oct 23;11:594352. doi: 10.3389/fpls.2020.594352. eCollection 2020.
Chelate induction of organic acids has been recognized to enhance metal uptake and translocation in plants, but the underlying mechanism remains unclear. In this study, seedlings of were hydroponically exposed to the combinations of Cd (0 and 50 μM) and three exogenous organic acids (100 μM of citric, tartaric, or malic acid). Plant biomass, antioxidant enzymes, non-protein thiol compounds (NPT) content, and the expression of candidate genes associated with Cd accumulation and tolerance were determined. Results showed that Cd significantly inhibited plant biomass but stimulated the activity of antioxidant enzymes in the roots and leaves, while the lipid peroxidation increased as well. Respective addition of three organic acids greatly enhanced plant resistance to oxidative stress and reduced the lipid peroxidation induced by Cd, with the effect of malic acid showing greatest. The addition of organic acids also significantly increased the content of glutathione in the root, further improving the antioxidant capacity and potential of phytochelatin biosynthesis. Moreover, Cd induced the expression level of candidate genes in roots of . The addition of three organic acids not only promoted the expression of candidate genes but also drastically increased Cd accumulation in . In summary, application of citric, tartaric, or malic acid alleviated Cd-imposed toxicity through the boost of enzymatic and non-enzymatic antioxidants and candidate gene expression, while their effects on Cd tolerance and accumulation of differed.
螯合诱导有机酸已被认为可增强植物对金属的吸收和转运，但其潜在机制仍不清楚。在本研究中，将[植物名称缺失]幼苗水培暴露于镉（0和50 μM）与三种外源有机酸（100 μM柠檬酸、酒石酸或苹果酸）的组合中。测定了植物生物量、抗氧化酶、非蛋白硫醇化合物（NPT）含量以及与镉积累和耐受性相关的候选基因的表达。结果表明，镉显著抑制植物生物量，但刺激了根和叶中抗氧化酶的活性，同时脂质过氧化也增加。分别添加三种有机酸极大地增强了植物对氧化应激的抗性，并降低了镉诱导的脂质过氧化，其中苹果酸的效果最为显著。添加有机酸还显著增加了根中谷胱甘肽的含量，进一步提高了抗氧化能力和植物螯合素生物合成的潜力。此外，镉诱导了[植物名称缺失]根中候选基因的表达水平。添加三种有机酸不仅促进了候选基因的表达，还大幅增加了[植物名称缺失]中镉的积累。总之，柠檬酸、酒石酸或苹果酸的施用通过增强酶促和非酶促抗氧化剂以及候选基因表达来减轻镉造成的毒性，而它们对[植物名称缺失]镉耐受性和积累的影响有所不同。
