Function and application of the Eutrema salsugineum PHT1;1 gene in phosphate deficiency stress.

Low availability of inorganic phosphate (Pi) in soil is often a limiting factor for plant growth and productivity. The Pi transporter plays an important role in the absorption and utilization of phosphorus in plants. Eutrema salsugineum shows strong tolerance under Pi stress conditions, but the function of the E. salsugineum PHT1 genes has not yet been systematically studied. This study isolated a phosphate transporter gene (EsPHT1;1) from the halophyte E. salsugineum and functionally characterized it in the herbaceous model plant, Arabidopsis thaliana, and in an important oil crop species, soybean (Glycine max (L.) Merr.). Under Pi deficient conditions, transgenic Arabidopsis and transgenic soybean grew better and exhibited significant improvement in root growth, biomass accumulation and seed yield compared with wild-type (WT) plants. These phenotypic enhancements were more apparent under inadequate Pi conditions than under sufficient or no Pi conditions, which is in agreement with the observation that the transgenic plants accumulated higher amounts of Pi and total P in shoots and roots than WT plants only when inadequate Pi was supplied. The results of the present study indicate that overexpression of EsPHT1;1 can efficiently enhance the growth and reproductive performance of both Arabidopsis and soybean plants challenged by low P stress, which results confirm the important role of PHT1;1 in dealing with Pi deficiency.