College of Landscape Architecture, Sichuan Agricultural University, Wenjiang, Sichuan, 611130, PR China.
College of Tourism and Urban-Rural Planning, Chengdu University of Technology, No. 1, Dongsan Road, Erxianqiao, Chenghua, Sichuan, 610051, PR China.
Ecotoxicol Environ Saf. 2020 Jan 15;187:109831. doi: 10.1016/j.ecoenv.2019.109831. Epub 2019 Oct 22.
Lead is one of the most hazardous pollutants to both the environment as well as human beings. As one of the approaches to enhance phytoremediation, brassinosteroids are predicted as a potential candidate phytohormone for assisted phytoremediation. Few studies have focused on the physiological regulations of tall fescue plants (Festuca arundinacea Schreb.), a potential phytoremediation species, for its responses to applications of brassinosteroids under lead stress. Therefore, the objectives of this study were to investigate the effects of foliar application of 24-epibrassinolide, a brassinosteroids analogue, on reactive oxygen species accumulation and antioxidative defense systems of tall fescue when exposed to lead, and ultimately its potential to be used in phytoremediation. When exposed to lead (1000 mg/kg) for 80 d, decreases in shoot and root biomass of tall fescue biomass as well as chlorophyll and carotenoid productions were found. Foliar application of 24-epibrassinolide at three rates and five applications every 7 d improved the biomass of both shoots and roots, and increased the photosynthetic pigments. The improved lead tolerance in tall fescue plants after 24-epibrassinolide applications was associated with reduced HO and O accumulations and increased antioxidative enzyme activities including superoxide dismutase, catalase, and guaiacol peroxidase. Additionally, osmoprotectants increased and lipid peroxidation decreased. Ultimately, foliar applications of 24-epibrassinolide enhanced the lead recovery rate of tall fescue plants, proving its potential role in phytoremediation for soil contaminated with heavy metals such as lead.
铅是对环境和人类危害最大的污染物之一。作为增强植物修复的方法之一,油菜素内酯被预测为辅助植物修复的潜在候选植物激素。很少有研究关注高羊茅(Festuca arundinacea Schreb.)植物的生理调节,高羊茅是一种潜在的植物修复物种,其对油菜素内酯在铅胁迫下的反应。因此,本研究的目的是研究叶面喷施油菜素内酯类似物 24-表油菜素内酯对高羊茅在铅暴露下活性氧积累和抗氧化防御系统的影响,最终探讨其在植物修复中的应用潜力。当高羊茅暴露于铅(1000mg/kg)80d 时,发现高羊茅生物量的地上和地下生物量以及叶绿素和类胡萝卜素的产生减少。叶面喷施 24-表油菜素内酯在三个剂量和五个剂量,每 7d 一次,提高了地上和地下生物量,并增加了光合色素。24-表油菜素内酯处理后高羊茅植物对铅的耐受性提高与 HO 和 O 积累减少以及抗氧化酶活性增加有关,包括超氧化物歧化酶、过氧化氢酶和愈创木酚过氧化物酶。此外,渗透调节剂增加,脂质过氧化减少。最终,叶面喷施 24-表油菜素内酯提高了高羊茅植物对铅的回收率,证明了其在重金属(如铅)污染土壤的植物修复中的潜在作用。