生态环境学报Issue(7)：1217-1221,5.
多金属富集植物李氏禾根系对铜吸收机理的研究
Mechanisms of Cu Uptake in a Multi-metal Accumulating Plant Leersia hexandra Swartz
摘要
Abstract
Leersia hexandra Swartz is a multi-metal accumulating plant. The study on the mechanisms of Cu uptake by roots of L. hexandra will help to understand how plants accumulate copper. Additionally, understanding Cu uptake mechanisms in plants is also valuable for phytoremediation of Cu-contaminated soil by L. hexandra. In the present work, a series of greenhouse hydroponic experiments were carried out to study the relationship of Cu2+uptake with Ca2+and K+channels using a calcium ion channel blocker (LaCl3) and a potassium ion channel blocker (TEA). Effects of ATPase inhibitor, uncoupler, and low temperature on Cu2+uptake by roots of L. hexandra were also studied, respectively. Based on these experiments, Cu uptake mechanisms in L. hexandra were discussed. The results showed that Ca2+channel blocker significantly limited the Cu uptake (p<0.05). After 48 h treatment with 1 mmol·L-1 LaCl3, Cu concentration in the roots was decreased by 39.2%as compared to the control group, which indicated that Cu uptake by roots of L. hexandra was closely related to Ca2+ channel. Conversely, K+ channel blocker did not inhibit Cu uptake, suggesting that Cu2+did not pass through potassium ion channels. ATPase inhibitor (Na3VO4) significantly limited the Cu uptake (p<0.05). Cu concentrations in the roots exposed to 25 μmol·L-1 and 50 μmol·L-1 Na3VO4 for 48 h were decreased by 26.2% and 31.0%, respectively. Therefore, the Cu uptake by the roots of L. hexandra may need energy consumption. This was supported by the observation that Cu uptake was significantly limited by an uncoupler, 2, 4-dinitrophenol (DNP). Cu concentrations in roots were decreased by 25.8% and 42.7% compared to control after 48 h exposure to 25 μmol·L-1 and 50 μmol·L-1 DNP. Effects of low temperature on Cu uptake were more pronounced than those of ATPase inhibitor and uncoupler. Cu concentration in roots was decreased by 60.1% at 2 ℃ for 48 h. The result confirmed that the Cu uptake by roots of L. hexandra was an active process dependent on energy consumption.关键词
李氏禾/铜/吸收/抑制剂/主动运输Key words
L. hexandra/Cu/uptake/inhibitors/active transport分类
资源环境引用本文复制引用
田静,张学洪,陈俊,刘杰..多金属富集植物李氏禾根系对铜吸收机理的研究[J].生态环境学报,2014,(7):1217-1221,5.基金项目
国家自然科学基金项目(41361085)；“八桂学者”建设工程专项经费资助；广西危险废物处置产业化人才小高地基金 （41361085）
