Arsenic Hyperaccumulator Pteris vittata L. and Its Application to the Field

Abstract

Arsenic-contaminated soil is a serious problem in China, which threatens the safety of drinking water and food. Phytoremediation, an emerging, plant-based technology for the removal of toxic contaminants from soil, has been receiving renewed attention. The discovery of the As hyperaccumulator Pteris vittata L. opens a door for the phytoremediation of arsenic-contaminated soils. The mechanisms of arsenic uptake, translocation, and transformation by this plant have been studied. The hyperaccumulation and hypertolerance characteristics and mechanisms have been disclosed. Antioxidative system, compartmentation, and chelation may contribute to the tolerance of hyperaccumulators. The reduction of As (V) to As (III) (>50% of As in aboveground parts existed as As (III)), the high concentration of phosphor in root (48–53% of P in P. vittata distributed in roots), and the efficient translocation of As from roots to aboveground parts (percentage of aboveground As accounted for 73–77% of total As) were suggested as essential processes for the hyperaccumulation of As in P. vittata. Studies on population differences and multimetal accumulating theories were also summarized. In situ phytoremediation projects using P. vittata have been established, with high As removal rates achieved. The first international phytoremediation project was established in Chenzhou, Hunan Province. Afterward, more phytoremediation projects were established in the Guangxi Zhuang Autonomous Region, Yunnan Province, Henan Province, Hebei Province, and Beijing City. During the phytoremediation practices, some problems that cannot be confronted in the lab were faced, and through both lab and field investigation, some key cultivation and management issues were studied, including the reproduction, optimized fertilizer, intercropping technology, harvesting, incineration, and cost calculation. Based on these previous studies, future research directions were pointed out.