Xu Bo, Yu Shen, Ding Jing, Wu Shengchun, Ma Jun
a Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences , Xiamen , China.
Int J Phytoremediation. 2015;17(1-6):175-81. doi: 10.1080/15226514.2013.876965.
Iris pseudacorus L. (yellow flag) is a wide-use wetland plant for constructed wetlands for removing metals from wastewater. This study aims to understand effects of root iron plaque on sequestration and translocation of Cr and Ni in yellow flag seedlings using a hydroponic experiment. Yellow flag seedlings (4-week-old seedlings with 4-6 leaves) with or without iron plaque induction (at 50 mg Fe2+ L(-1) for 72 hours) were spiked for 6 days in the Hoagland solution with Cr or Ni at 0.5, 5, and 50 mg L(-1), equivalent to 1, 10, 100 times of thresholds of surface water quality, respectively. Results indicated that root iron plaque significantly reduced translocation of Cr and Ni to root but increased from root to shoot. Root iron plaque formation counteracted Cr toxicity to yellow flag seedlings while the control showed Cr toxicity to root at 5 mg L(-1)and to shoot at 50 mg L(-1) with significant biomass loss. Neither Ni exposures caused significant biomass loss nor root iron plaque formation significantly changed Ni distribution among plant parts. Our study suggests that root iron plaque effects on metal sequestration and translocation in yellow flag seedlings were metal-dependent.
黄菖蒲（Iris pseudacorus L.）是一种广泛用于人工湿地以去除废水中金属的湿地植物。本研究旨在通过水培实验了解根际铁膜对黄菖蒲幼苗中铬和镍的螯合与转运的影响。将有或没有铁膜诱导（在50 mg Fe2+ L(-1) 条件下处理72小时）的黄菖蒲幼苗（4周龄，4 - 6片叶）在含有0.5、5和50 mg L(-1) 铬或镍的霍格兰溶液中培养6天，这些浓度分别相当于地表水水质阈值的1、10和100倍。结果表明，根际铁膜显著降低了铬和镍向根部的转运，但增加了从根部向地上部的转运。根际铁膜的形成抵消了铬对黄菖蒲幼苗的毒性，而对照组在5 mg L(-1) 时对根部表现出铬毒性，在50 mg L(-1) 时对地上部表现出铬毒性，且生物量显著损失。镍处理均未导致显著的生物量损失，根际铁膜的形成也未显著改变镍在植物各部位的分布。我们的研究表明，根际铁膜对黄菖蒲幼苗中金属螯合和转运的影响取决于金属种类。
