Molecular characterization and expression analysis of phosphate transporter gene TaPT2-1 in wheat (Triticum aestivum L.)

Abstract

A transcript-derived fragment (TDF) showing up-regulated expression under low Pi stress and being identical to an uncharacterized phosphate transporter gene TaPT2-1 was cloned in wheat. TaPT2-1 was 2075 bp in length and encoded a 568-aa polypeptide. Transmembrane prediction analysis suggested that TaPT2-1 had 13 conserved transmembrane domains. TaPT2-1 shared much higher similarities to other four homologs from Arabidopsis thaliana, Solanum tuberosum, Capsicum frutescens, and Solanum melongena. The expression of TaPT2-1 was root specific and low Pi inducible, suggesting that it plays roles in roots and is involved in the Pi acquisition under Pi-starved condition. The promoter region of TaPT2-1 was cloned based on genome walk analysis. Several types of cis-regulatory elements, such as low Pi responding and tissue specific, were identified in TaPT2-1 promoter. The transgenic tobacco plants with the integrated TaPT2-1 promoter GUS were generated, and GUS histochemical staining analysis in the roots and leaves of the transgenic plants was performed. The results of GUS staining in roots and leaves under various Pi supply conditions were in accordance with the TaPT2-1 transcripts detected based on RT-PCR analysis. Taken together, the distinct expression of low Pi-induced and root-specific TaPT2-1 suggested that it could be used as the potential gene resource on generation of elite crop germplasms with high Pi use efficiency in the future.