A nodule‐localized phosphate transporter Gm PT 7 plays an important role in enhancing symbiotic N 2 fixation and yield in soybean

Summary Symbiotic nitrogen (N 2 ) fixation plays a vital role in sustainable agriculture. Efficient N 2 fixation requires various materials, including phosphate (Pi); however, the molecular mechanism underlying the transport of Pi into nodules and bacteroids remains largely unknown. A nodule‐localized Pi transporter, Gm PT 7, was functionally characterized in soybean ( Glycine max ) and its role in N 2 fixation and yield was investigated via composite and whole transgenic plants. Gm PT 7 protein was localized to the plasma membrane and showed transport activity for Pi in yeast. Altered expression of Gm PT 7 changed 33 Pi uptake from rhizosphere and translocation to bacteroids. Gm PT 7 was mainly localized to the outer cortex and fixation zones of the nodules. Overexpression of Gm PT 7 promoted nodulation, and increased plant biomass, shoot nitrogen and phosphorus content, resulting in improved soybean yield by up to 36%. Double suppression of Gm PT 5 and Gm PT 7 led to nearly complete elimination of nodulation and over 50% reduction in plant biomass, shoot nitrogen and phosphorus content, indicating that both Gm PT 7 and Gm PT 5 contribute to Pi transport for N 2 fixation. Taken together, our results indicate that Gm PT 7 is a transporter responsible for direct Pi entry to nodules and further to fixation zones, which is required for enhancing symbiotic N 2 fixation and grain yield of soybean.