Evidence of vacuolar compartmentalization of arsenic in the hyperaccumulator Pteris vittata  

作　　者：YANG XueXi CHEN Hui DAI XiaoJing XU WenZhong HE ZhenYan MA Mi 

机构地区：[1]Key Laboratory of Photosynthesis and Environmental Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China [2]College of Life Science, Beijing Normal University, Beijing 100875, China [3]School of Biotechnology, Southern Medical University, Guangzhou 510515, China

出　　处：《Chinese Science Bulletin》2009年第22期4229-4233,共5页

基　　金：Supported by the National High Technology Research and Development Program of China (Grant No. 2007AA021404);National Natural Science Foundation of China (Grant No. 30670171)

摘　　要：Pteris vittata can hyperaccumulate arsenic (As) to >1% of its dry weight without showing any signs of toxicity, indicating the existence of effective plant-internal detoxification mechanisms. Although vacuolar compartmentalization is known to play an important role in heavy metal detoxification and tolerance, direct evidence of arsenic compartmentalization in this hyperaccumulator was lacking. Here we report the subcellular localization of As in the callus of P. vittata. The callus induced from gametophytes of P. vittata exposed to 0.2 mmol/L arsenate for 20 days were examined by directly isolating cell walls, protoplasts and vacuoles, and determining arsenic concentrations. Of the total As in the callus, about 94% was in the protoplast, and of that, 91% was present in the vacuoles, indicating that vacuoles are a major storage site for As in P. vittata. In addition, the changes in the chemical components of vacuoles were analyzed by Fourier transform infrared spectroscopy (FTIR).Pteris vittata can hyperaccumulate arsenic （As） to 〉1% of its dry weight without showing any signs of toxicity, indicating the existence of effective plant-internal detoxificaUon mechanisms. Although vacuolar compartmentalization is known to play an important role in heavy metal detoxification and tolerance, direct evidence of arsenic compartmentalization in this hyperaccumulator was lacking. Here we report the subcellular localization of As in the callus of P. vittata. The callus induced from gametophytes of P. vittata exposed to 0.2 mmol/L arsenate for 20 days were examined by directly isolating cell walls, protoplasts and vacuoles, and determining arsenic concentrations. Of the total As in the callus, about 94% was in the protoplast, and of that, 91% was present in the vacuoles, indicating that vacuoles are a major storage site for As in P. vittata. In addition, the changes in the chemical components of vacuoles were analyzed by Fourier transform infrared spectroscopy （FTIR）.

关 键 词：超富集植物 条块分割 蜈蚣草 液泡 证据 愈伤组织诱导 傅立叶变换红外光谱 砷 

分 类 号：X53[环境科学与工程—环境工程] G222[文化科学]