Department of Environmental Sciences, University of Gujrat, Gujrat, 50700, Pakistan.
Department of Environmental Sciences and Engineering, Government College University, Allama Iqbal Road, Faisalabad, 38000, Pakistan.
Environ Sci Pollut Res Int. 2018 Sep;25(25):25390-25400. doi: 10.1007/s11356-018-2508-y. Epub 2018 Jun 27.
Phytoremediation is a cost-effective and eco-friendly technique for the removal of heavy metal-contaminated soils and water. The less availability and mobility of heavy metals in medium decreased the efficiency of this technique. The mobility and availability of these metals in the medium can be enhanced by the addition of organic chelators. The present study was conducted to investigate the possibility of glutamic acid (GA) in improving silver (Ag) phytoextraction by sunflower (Helianthus annuus L.). Different concentrations of Ag and GA were supplied in solution form in different combinations after defined intervals. Results depicted that increasing concentration of Ag significantly reduced the plant biomass, photosynthetic pigments, and antioxidant enzyme activities (like catalase, peroxidase, ascorbate, peroxidase, superoxide dismutase). Furthermore, Ag stress increased the Ag concentration and the production of reactive oxygen species (ROS) in sunflower plants. The addition of GA alleviated the Ag-induced toxicity in plants and enhanced Ag concentration and accumulation in sunflower. The addition of GA enhanced Ag accumulation in sunflower roots by 70, 79, 58, and 66% at 0-, 100-, 250-, and 500-μM Ag treatments, respectively, as compared to control plants. In conclusion, the results showed that Ag significantly reduced the physiological and biochemical attributes in term of reduced growth of sunflower and the addition of GA alleviated the Ag induced toxicity and enhanced Ag uptake. The results suggested that sunflower can be used as hyper-accumulator plant for the removal of Ag under GA. Further studies are required to understand the role of GA at gene and microscopic level in plants.
植物修复是一种经济且环保的技术，可用于去除受重金属污染的土壤和水。减少重金属在介质中的有效性和迁移性会降低该技术的效率。通过添加有机螯合剂可以增强这些金属在介质中的迁移性和有效性。本研究旨在探讨谷氨酸（GA）是否有可能通过向日葵（Helianthus annuus L.）提高银（Ag）的植物提取效率。在不同的间隔时间后，以溶液的形式将不同浓度的 Ag 和 GA 分别添加到不同的组合中。结果表明，Ag 浓度的增加显著降低了植物生物量、光合色素和抗氧化酶活性（如过氧化氢酶、过氧化物酶、抗坏血酸、过氧化物酶、超氧化物歧化酶）。此外，Ag 胁迫增加了向日葵植物中的 Ag 浓度和活性氧（ROS）的产生。GA 的添加缓解了植物中的 Ag 诱导毒性，并增强了 Ag 在向日葵中的浓度和积累。与对照植物相比，GA 的添加分别使 0、100、250 和 500 μM Ag 处理下向日葵根部的 Ag 积累增加了 70%、79%、58%和 66%。总之，结果表明，Ag 显著降低了向日葵的生理和生化特性，降低了其生长，而 GA 的添加缓解了 Ag 诱导的毒性并增强了 Ag 的吸收。结果表明，在 GA 存在下，向日葵可以作为超积累植物用于去除 Ag。需要进一步的研究来了解 GA 在植物中的基因和微观水平上的作用。
