Enhanced arsenic accumulation in hyperaccumulator Pteris vittata under elevated zinc conditions: Arsenic-related gene expression and implications for phytoremediation applications. Arsenic-related gene expression and implications for phytoremediation applications

Micronutrient Zn is toxic to plants at elevated concentrations. Interestingly, elevated Zn levels promote both plant growth and As uptake in As-hyperaccumulator Pteris vittata, though the mechanisms are unclear. In this study, P. vittata was hydroponically cultivated with 50 mu M As and varying Zn levels at 0.8-75 mu M. The 5 mu M Zn treatment was the most effective, increasing plant biomass by 39 % and reducing malondialdehyde by 28 %, indicating lowered oxidative stress in P. vittata. Its frond As content increased by 57 %, while root P decreased by 30 %. Gene analysis showed reduced expression of P-transporter PvPht1;2, and increased expression of As-related P-transporters PvPht1;3/1;4, AsV reductases PvHAC1/2 and AsIII antiporters PvACR3;2/3;3. The results suggest enhanced As uptake, reduction, and transport under elevated Zn levels. The study highlights 5 mu M Zn as optimal for promoting As accumulation and plant growth in P. vittata, offering potential for improving phytoremediation of As-contaminated sites.