Functional study and elite haplotype identification of soybean phosphate starvation response transcription factors and .

Unlabelled: Phosphorus (P) is one of the important mineral elements required for plant growth and development. However, because of the low mobility in soil, P deficiency has been an important factor limiting soybean production. Here, we identified 14 (phosphate starvation response) genes in soybean genome and verified that two previously unreported members, and , were involved in low-P stress tolerance in soybean. and were present in two diverged branches of the phylogenic tree. Both genes were highly expressed in roots and root nodules and were induced by P deficiency. GmPHR14 and GmPHR32 both were expressed in the nucleus. The 211 amino acids in the N terminus of GmPHR32 were found to be required for the transcriptional activity. Overexpressing or in soybean hairy roots significantly increased roots and shoots dry weight under low-P condition, and overexpressing additionally significantly increased roots P concentration under low-P condition. and were polymorphic in soybean population and the elite haplotype2 (Hap2) for both genes was preferentially present in improved cultivars and showed significantly higher shoots dry weight under low-P condition than the other two haplotypes. These results suggested and both positively regulated low-P responses in soybean, and would shed light on the molecular mechanism of low-P stress tolerance. Furthermore, the identified elite haplotypes would be useful in P-efficient soybean breeding.

Supplementary Information: The online version contains supplementary material available at 10.1007/s11032-022-01301-z.