Arsenic uptake, arsenite efflux and plant growth in hyperaccumulator Pteris vittata: Role of arsenic-resistant bacteria
writer:Han, Y. H., J. W. Fu, Y. Chen, B. Rathinasabapathi, and L. Q. Ma*
keywords:Pteris vittata; Endophytic bacteria; Rhizospheric bacteria; Arsenic reducing bacteria; Arsenic oxidizing bacteria; Arsenite efflux
source:期刊
specific source:Chemosphere
Issue time:2016年
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 < 0.05). Though AsV was supplied, 95% of the As in the bacteria-free media was AsIII, suggesting efficient efflux of AsIII by PV roots (120 μg g–1 root fw). This was supported by the fact that no AsV was detected in media inoculated with As-reducers while 95% of AsV was detected with As-oxidizer. Our data showed that, under As-stress, PV reduced As toxicity by efficient AsIII efflux into media and AsIII translocation to the fronds, and bacteria benefited PV growth probably via enhanced As and P uptake.