By using sand culture,we made comparisons between the T₃ transgenic lines overexpressed a rice (Oryza sativa L.) phosphate transporter gene OsPT6 and their non-transgenic (NT) host cultivar to examine the differences in the traits of growth and development,the concentrations of available phosphorus,total phosphorus,total nitrogen,and leghemoglobin,the activities of glutamine synthetase and the contents of seed proteins in vegetable soybean under low phosphorus conditions.In addition,the relative expression levels of some genes related to the nodulation and nitrogen fixation in roots were also measured.The purpose of this research was to provide the theoretical basis for elucidating the mechanisms of nodulation and nitrogen fixation in the roots of the transgenic plants under phosphorus deficiency.The results showed that:(1)the plant height,stem diameter,numbers of flowers,pods and root nodules of the transgenic plants were significantly higher than those of the NT plants.(2)The concentrations of available phosphorus in roots,stems,leaves and nodules,the contents of phosphorus and nitrogen of the whole plant,the concentrations of leghemoglobin in the nodules and the activities of glutamine synthetase in functional leaves of the transgenic plants were significantly higher than those of the NT plants.(3)The mutually significant positive correlations were observed among the concentrations of leghemoglobin,total phosphorus,total nitrogen,and the activity of glutamine synthetase.(4)The relative expression levels of GmENOD40a,GmENOD40b,GmGS1β1,GmGS1β2 genes in transgenic plants were significantly higher than those in the NT plants.The above results indicated that the overexpression of OsPT6 gene enhances the ability of nodulation and nitrogen fixation in the transgenic vegetable soybean under low phosphorus conditions,which lays the foundations for the further studies on their regulation mechanisms.