Characterizing the wheat ( L.) phosphate transporter gene family and analyzing expression patterns in response to low phosphorus stress during the seedling stage.

INTRODUCTION

Inorganic phosphorus (Pi) is an indispensable nutrient for plant growth, with phosphate transporter proteins (PHTs) having key roles in Pi uptake, transport, and signal transduction in plants. However, a systematic and comprehensive genomic analysis of the wheat family (covering and ) is lacking.

METHODS

In view of this, we successfully identified 180 () members in 6 PHT families using bioinformatics, and performed in-depth phylogenetic analyses between these protein sequences and family proteins from and an important rice crop.

RESULTS

We observed that the family could be subdivided into 6 phylogenetic clusters, specifically including 46 , 3 , 65 , 22 , 14 , and 30 members. We also comprehensively profiled the phylogenetic relationships, structural features, conserved motifs, chromosomal localization, cis-acting elements and subcellular localization of these members. These features showed a high degree of conservation within each subfamily. In particular, in the 2000 bp sequence upstream of the genes, we identified multiple cis-acting elements closely related to Pi responses, such as P1BS (PHR1 binding site), MBS (MYB binding site), and a W-box (WRKY binding site), which suggested that genes were possibly involved in Pi signaling pathways. We screened 24 genes by qRT-PCR (real-time quantitative PCR) and investigated their expression in roots and shoots of two wheat cultivars (Pi efficient material SW2 and Pi inefficient material SW14) under low Pi stress conditions. All genes showed up-regulated expression patterns associated with Pi nutritional status, with relative gene expression generally higher in the SW2 cultivar when compared to SW14. Particularly noteworthy was that in the SW2 cultivar showed high and relative stable expression in wheat roots. Combining our bioinformatics and relative gene expression analyses, we preliminarily screened as a candidate gene for low Pi tolerance and further confirmed its subcellular localization.

DISCUSSION

Our work not only identified important family roles in coping with low Pi stress, but it also provides a functional research basis and candidate gene resource for solving Pi deficiency-related problems.