Abstract

Developing P-efficient plants helps improve P uptake from soils with low-available P and reduce environmental damage by P runoff. Here, we investigated a novel root-specific phytase PvPHY1 from As-hyperaccumulator Pteris vittata , which can efficiently utilize phytate, a recalcitrant organic phosphorus in soil. Unlike other plants, expression of PvPHY1 in P. vittata was greater in the roots than the fronds. A pure phytase with considerable activity was obtained via prokaryotic expression. Expressing PvPHY1 in tobacco ( PvPHY1 -Ex) enhanced its growth (2.8 to 3.5–3.9 g per plant) and increased its P accumulation by 10–50% under low- and adequate-P conditions. Further, PvPHY1 -Ex tobacco showed 25–32% lower intracellular phytate and 30–56% higher inorganic P in the roots, likely due to phytase-mediated hydrolysis of phytate. Decrease of phytate levels up-regulated phosphate transporter genes ( NbPht1;1 , NbPht1;2 and NbPht1;6 ), leading to greater P and As uptake. However, As translocation to the shoots was low, probably due to competition from increased inorganic P via phytate hydrolysis. As such, PvPHY1 facilitated P uptake from soils and phytate hydrolysis in plants, thereby promoting tobacco growth. Overall, PvPHY1 from P. vittata helps better understand the novel phytase to increase soil P utilization efficiency, thereby reducing P fertilizer requirements for crop production.