State Key Lab of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Jiangsu 210023, China.
Soil and Water Science Department, University of Florida, Gainesville, FL 32611, United States.
Environ Pollut. 2017 Jul;226:212-218. doi: 10.1016/j.envpol.2017.04.021. Epub 2017 Apr 19.
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 in As+phytate, 2.2- and 3.1-fold that of As treatment. Phosphorus uptake by PV was reduced by 27% in As treatment than the control (P vs. P+As) but increased by 73% comparing phytate to phytate+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.
植酸在土壤中含量丰富，它很稳定，植物无法吸收。然而，它存在于砷超富集植物蜈蚣草（PV）的根分泌物中。为了阐明其对砷吸收和生长的影响，将 PV 和非砷超富集植物凤尾蕨（PE）在含有 50μM 砷和/或 50 或 500μM 植酸的琼脂培养基（63μM P）上培养 60 天。植酸诱导了 PV 中砷和磷的有效吸收，并促进了其生长，但对 PE 的影响很小。在含砷和植酸的处理中，PV 叶片和根中的砷浓度分别为 157 和 31mg/kg，分别是砷处理的 2.2 倍和 3.1 倍。与对照相比，砷处理使 PV 对磷的吸收减少了 27%（P 与 P+As），但与植酸相比，植酸+砷处理使磷的吸收增加了 73%，表明 PV 有效地从植酸中吸收了磷。砷和植酸均未影响 PV 中铁的积累，但植酸降低了 PE 中的根铁浓度（46-56%）。因此，PV 中砷和磷的增加以及铁吸收的未受抑制可能促进了 PV 的生长。因此，向砷污染土壤中添加植酸可能会促进 PV 对砷的吸收和生长及其植物修复能力。
