Arsenic uptake, arsenite efflux and plant growth in hyperaccumulator Pteris vittata: Role of arsenic-resistant bacteria

Bacteria-mediated arsenic (As) transformation and their impacts on As and P uptake and plant growth in As-hyperaccumulator Pteris vittata (PV) were investigated under sterile condition. All As-resistant bacteria (9 endophytic and 6 rhizospheric) were As-reducers except one As-oxidizer. After growing two months in media with 37.5 mg kg−1 AsV, As concentrations in the fronds and roots were 3655–5389 (89–91% AsIII) and 971–1467 mg kg−1 (41–73% AsIII), corresponding to 22–52% decrease in the As in the media. Bacterial inoculation enhanced As and P uptake by up to 47 and 69%, and PV growth by 20–74%, which may be related to elevated As and P in plants (r = 0.88–0.97, p