Genome-wide analysis of the phosphate transporter gene family in oats: insights into phosphorus and water deficiency responses.

Phosphorus (P) and water are essential for plant growth and development, exerting a significant influence on global crop production. The phosphate transporter (PHT) gene family plays a pivotal role in phosphate (Pi) uptake, transport, and homeostasis under diverse environmental conditions. In this study, we conducted a comprehensive genome-wide identification and characterization of the PHT gene family in Avena sativa. A total of 32 non-redundant AsPHT genes were identified in the OT3098 genome, classified into two subfamilies: AsPHT1 (21 genes) and AsPHO (11 genes). AsPHT1 proteins were predominantly hydrophobic with one or two exons, whereas AsPHO proteins were hydrophilic, exhibiting a more complex structure with 13-15 exons. Cis-regulatory element analysis revealed an abundance of hormone- and stress-responsive elements in the promoters of AsPHT genes, indicating their potential roles in adaptive responses to Pi and water deficiency. Gene expression profiling under low Pi and drought conditions demonstrated differential expression of 22 AsPHT genes in roots and leaves at the seedling stage, with distinct responses to the two stresses, highlighting the functional diversity of the AsPHT gene family. These findings provide valuable insights into the molecular mechanisms underlying Pi and water acquisition in oats and offer potential applications for developing varieties with enhanced Pi use efficiency and drought tolerance.