The arsenic (As) hyperaccumulation ability of Pteris vittata has been widely used in the remediation of As-contaminated soils in Southern China. The hyperaccumulation mechanisms of P. vittata are still poor understand. The reduction of As (V) to As(III) and the later upwards transfer of As(III) are regarded as the key physiological processes in P. vittata.

Dr. LEI Mei and her colleagues from the Environmental Remediation research group headed by Prof. CHEN Tongbin in the Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, investigated the transport and transformation of As in the rhizoids of P. vittata using a synchrotron X-ray microprobe. It was disclosed that the reduction of As(V) to As(III) occurred at the endodermis. Before reduced to As(III) at the endodermis, As(V) was transported using an energy dependent process closely associated with phosphate (P). This process can be enhanced by As (V) exposure or P deficiency but restrained by energy release inhibition caused by 2,4-dinitrophenol or sodium orthovanadate. In contrast, after As reduction, As(III) translocation differed from P translocation and was more efficient, appearing free from the apparent endodermal blockage.

Results provide important information for the As hyperaccumulation process in P. vittata. The relationship between As(V) and P disclosed in this study can also be used in the soil remediation projects. The further research based on this study has obtained the support from the Ministry of Environmental Protection, Ministry of Science and Technology, and the local government of pollution region. The phytoremediation techniques of this group are guiding Guangxi, Yunnan, Beijing, Guangdong, and Henan province to removed heavy metal contamination of land.

The research has been published in Environment Pollution. (Mei Lei, Xiao-ming Wan, Ze-chun Huang , Tong-bin Chen, et al.First evidence on different transportation modes of arsenic and phosphorus in arsenic hyperaccumulator Pteris vittata. EnvironPollut. 2012, 161: 1-7)