Function of TaPHT1;9 in phosphorus absorption and utilization under soil condition

Abstract

Abstract Background and aims Phosphorus (P) is one of the major constraints to wheat growth and development. Identifying P-efficient genes is crucial for improving phosphorusutilization efficiency (PUE). Our previous studies showed that TaPHT1;9 is a high-affinity phosphate transporter and functions on phosphate (Pi) absorption and transport in wheat seedlings under hydroponic condition, but its function under complex soil environments needs to further be measured. In this study, we aim to further explore its role under soil condition, and reveal its application potential in the breeding of the P-efficient wheat cultivars. Methods TaPHT1;9-ectopic expression transgenic rice plants and -edited wheat mutants were cultivated in soils with different Pi fertilizer treatments respectively. Grain yield, biomass, P concentration and PUE were measured and calculated. Results CRISPR-edited homozygous TaPHT1;9-A/B/D wheat mutants were screened and identified, and their grain yields, P accumulations and PUEs were significantly lower than wild-type (WT) control. And the reduced yields were mainly due to the decrease in grain number per spike and 1000-grain weight. TaPHT1;9-ectopic expression transgenic rice plants exhibited the opposite results and their grain yields, P accumulations and PUEs were significantly higher than WT plants under insufficient Pi fertilizer conditions. Conclusions Under soil condition, TaPHT1;9 plays a vital role in Pi utilizationand it is a candidate target gene for improving the PUE of crops.