Isolation and heterologous transformation analysis of a pollen-specific promoter from wheat (Triticum aestivum L.)

The promoter of a pollen-specific gene TaPSG719 was isolated from wheat (Triticum aestivum L.) by inverse-PCR (IPCR). Sequence analysis revealed that the promoter contains two cis-acting elements (AGAAA and GTGA) known to confer anther/pollen-specific gene expression which suggests that the promoter of TaPSG719 gene is a pollen-specific one. To ascertain the regulatory function of TaPSG719 promoter, two deleted fragments (-1,776 to -1 bp and -1,019 to -1 bp) were fused to the beta-glucuronidase (GUS) gene and transformed into tobacco plants. Similar GUS expression patterns were observed in all transformed plants and its activity was detected exclusively in pollen. No GUS activity in any other floral or vegetative tissue was observed. The results confirm that TaPSG719 promoter is pollen-specific and active during the middle stages of pollen development till anther matured, and it can drive pollen-specific gene expression across the species.