Overexpression of Rice Phosphate Transporter Gene OsPT2 Enhances Tolerance to Low Phosphorus Stress in Soybean

Low phosphorous (P) availability in soils limits production of soybean [ Glycine max (L.) Merr.] around the world. This study was conducted to determine whether exogenous expression of the rice ( Oryza sativa L.) phosphates transporter gene OsPT2 would increase inorganic phosphates (Pi) acquisition and improve yield in transgenic soybean. Cotyledonary-node explants of the soybean were inoculated with the Agrobacterium tumefaciens strain EHA105 harboring the vector pCAMBIA3301-OsPT2 , which contained OsPT2 , gus and bar genes. Ten fertile T 0 transgenic plants were obtained and semiquantitative RT-PCR of progenies demonstrated that OsPT2 gene was overexpressing in the T 2 generation. Three T 2 transgenic lines overexpressing OsPT2 were selected and subjected to testing for tolerance to low concentrations of Pi (low-Pi; 20 µM Pi) by hydroponic culture using modified Hoagland’s nutrient solution. The total P contents in the leaves, stems, roots, and seeds of the transgenic plants significantly increased under the concentrations of low-Pi and 1,000 µM Pi of standard Hoagland’s nutrient solution. Under low-Pi stress, the yields of the transgenic lines were significantly higher than those of the wild type. Taken together, our data suggest that the overexpression of OsPT2 in transgenic soybean lines improves Pi acquisition and seed yield, and OsPT2 may serve as one of the promising target genes that can be manipulated in crop improvement for minor use of Pi fertilizers.