Zhang Xin, Lin Ai-Jun, Zhao Fang-Jie, Xu Guo-Zhong, Duan Gui-Lan, Zhu Yong-Guan
State Key Lab of Urban and ONAL Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, 18 Shuangqing Road, Beijing 100085, China.
Environ Pollut. 2008 Dec;156(3):1149-55. doi: 10.1016/j.envpol.2008.04.002. Epub 2008 May 23.
This study investigates As accumulation and tolerance of the aquatic fern Azolla. Fifty strains of Azolla showed a large variation in As accumulation. The highest- and lowest-accumulating ferns among the 50 strains were chosen for further investigations. Azolla caroliniana accumulated two times more As than Azolla filiculoides owing to a higher influx velocity for arsenate. A. filiculoides was more resistant to external arsenate due to a lower uptake. Both strains showed a similar degree of tolerance to internal As. Arsenate and arsenite were the dominant As species in both Azolla strains, with methylated As species accounting for <5% of the total As. A. filiculoides had a higher proportion of arsenite than A. caroliniana. Both strains effluxed more arsenate than arsenite, and the amount of As efflux was proportional to the amount of As accumulation. The potential of growing Azolla in paddy fields to reduce As transfer from soil and water to rice should be further evaluated.
本研究调查了水生蕨类植物满江红对砷的积累和耐受性。50个满江红菌株在砷积累方面表现出很大差异。从这50个菌株中选出积累量最高和最低的蕨类植物进行进一步研究。由于对砷酸盐的流入速度较高，卡罗来纳满江红积累的砷比细叶满江红多两倍。由于吸收较低，细叶满江红对外部砷酸盐更具抗性。两种菌株对内部砷的耐受性程度相似。砷酸盐和亚砷酸盐是两种满江红菌株中主要的砷形态，甲基化砷形态占总砷的比例小于5%。细叶满江红中亚砷酸盐的比例高于卡罗来纳满江红。两种菌株流出的砷酸盐都比亚砷酸盐多，砷流出量与砷积累量成正比。应进一步评估在稻田中种植满江红以减少砷从土壤和水向水稻转移的潜力。
