Phytate induced arsenic uptake and plant growth in arsenic-hyperaccumulator Pteris vittata

•Studied impact of phytate on As uptake by As-hyperaccumulator P. vittata.•P. vittata effectively used phytate and was efficient in Fe utilization.•Phytate induced efficient As uptake and growth in P. vittata.•Phytate can enhance phytoremediation of As-contaminated soils by P. vittata.

Phytate is abundant in soils, which is stable and unavailable for plant uptake. However, it occurs in root exudates of As-hyperaccumulator Pteris vittata (PV). To elucidate its effect on As uptake and growth, P. vittata were grown on agar media (63 μM P) containing 50 μM As and/or 50 or 500 μM phytate with non As-hyperaccumulator Pteris ensiformis (PE) as a congeneric control for 60 d. Phytate induced efficient As and P uptake, and enhanced growth in PV, but had little effects on PE. The As concentrations in PV fronds and roots were 157 and 31 mg kg−1 in As50+phytate50, 2.2- and 3.1-fold that of As50 treatment. Phosphorus uptake by PV was reduced by 27% in As treatment than the control (P vs. P+As) but increased by 73% comparing phytate500 to phytate500+As, indicating that PV effectively took up P from phytate. Neither As nor phytate affected Fe accumulation in PV, but phytate reduced root Fe concentration in PE (46-56%). As such, the increased As and P and the unsuppressed Fe uptake in PV probably promoted PV growth. Thus, supplying phytate to As-contaminated soils may promote As uptake and growth in PV and its phytoremediation ability.

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