Farid Mujahid, Farid Sheharyaar, Zubair Muhammad, Ghani Muhammad Awais, Rizwan Muhammad, Ishaq Hafiz Khuzama, Alkahtani Saad, Abdel-Daim Mohamed M, Ali Shafaqat
Department of Environmental Sciences, University of Gujrat, Gujrat, Pakistan.
Department of Environmental Sciences and Engineering, Government College University, Faisalabad, Pakistan.
Front Plant Sci. 2020 Sep 9;11:1297. doi: 10.3389/fpls.2020.01297. eCollection 2020.
Chelator-assisted phytoremediation is an economical, sustainable, and ecologically friendly method of extracting heavy metals and metalloids from the soil. Organic chelators are thought to enhance metal availability and mobility in contaminated media, thereby improving phytoextraction. The aim of the present study was to examine whether exogenous application of glutamic acid (GA) could improve chromium (Cr) phytoextraction by sunflower plants ( L.). Seeds were planted in plastic pots filled with 5 kg of local agricultural soil spiked with increasing concentrations of Cr (1, 2, and 5 mg kg). Glutamic acid (5 mM) was applied to soil in solution according to a completely randomized experimental design, and the sunflower plants were harvested after 8 weeks. The results indicated that increasing Cr-induced stress significantly inhibited plant growth, leading to reduced biomass, photosynthetic pigment content, activities of antioxidant enzymes, and leaf area of the sunflower plants. However, exogenous addition of GA significantly reduced the Cr-associated toxic effects while also increasing the accumulation of Cr in the plants. Moreover, increasing concentrations of Cr in the soil increased the generation of reactive oxygen species (ROS) responsible for the altered antioxidant enzyme activities. The results revealed that GA application to the topsoil enhanced the Cr concentration and accumulation in the root, stem, and leaves by up to 254, 225, 355, and 47, 59, 150% respectively. Further the GA addition reduced the Cr-induced toxicity in plants and might be helpful for enhancing Cr phytoextraction by sunflower plants.
螯合剂辅助植物修复是一种从土壤中提取重金属和类金属的经济、可持续且生态友好的方法。有机螯合剂被认为可以提高污染介质中金属的有效性和迁移性，从而改善植物提取效果。本研究的目的是检验外源施用谷氨酸（GA）是否能提高向日葵（L.）对铬（Cr）的植物提取能力。将种子种植在装有5千克添加了浓度递增的Cr（1、2和5毫克/千克）的当地农业土壤的塑料盆中。根据完全随机试验设计，将谷氨酸（5毫摩尔）以溶液形式施用于土壤中，8周后收获向日葵植株。结果表明，Cr诱导的胁迫增加显著抑制了植物生长，导致向日葵植株的生物量、光合色素含量、抗氧化酶活性和叶面积降低。然而，外源添加GA显著降低了与Cr相关的毒性作用，同时也增加了植物中Cr的积累。此外，土壤中Cr浓度的增加导致了负责改变抗氧化酶活性的活性氧（ROS）的产生。结果表明，在表土中施用GA分别使根、茎和叶中的Cr浓度和积累量提高了254%、225%、355%以及47%、59%、150%。此外，添加GA降低了植物中Cr诱导的毒性，可能有助于提高向日葵对Cr的植物提取能力。
