Phytoextraction potential of Pteris vittata L. co-planted with woody species for As, Cd, Pb and Zn in contaminated soil

The objective of this study was to determine the phytoextraction potential of a hyperaccumulator co-planted with a large biomass of woody plant in metal(loid)-contaminated soil. A pot experiment was conducted for 270 days (d) to study the growth, physiological responses, and metal(loid)s accumulation characteristics of plants, which included a shade-requiring, As-hyperaccumulator perennial herb, Pteris vittata L., co-planted with a woody tree, namely Morus alba L. or Broussonetia papyrifera L., for soil contaminated with arsenic (As), cadmium (Cd), lead (Pb), and zinc (Zn). The results showed that the biomass, photosynthetic pigment contents, antioxidant enzyme activity, and uptake of As in P. vittata L. were significantly enhanced by co-planting with M. alba L. or B. papyrifera L. Especially, the uptake of As by P. vittata L. was significantly (p < 0.05) increased by 80.0% and 64.2% when it was co-planted with M. alba L. or B. papyrifera L., respectively, while the As, Cd, Pb, and Zn contents of both M. alba L. and B. papyrifera L. were not significantly promoted by the co-planting. The comprehensive phytoextraction of metal(loid)s could be optimized by the co-planting of P. vittata L. with M. alba L. or B. papyrifera L. The total amount of As in the shoots from co-planting species was significantly (p < 0.05) higher than that of the monoculture with M. alba L. or B. papyrifera L., and that of Cd and Zn in the shoots was significantly (p < 0.05) higher than that of the monoculture with P. vittata L. The results showed that the co-planting of P. vittata L. with M. alba L. or B. papyrifera L. can alleviate the toxic effects of metal(loid)s on plant growth and improve the comprehensive phytoextraction amounts of metal(loid)s, and is a promising strategy for remediation of metal(loid)-contaminated soil.