Cloning, characterization and promoter analysis of S-RNase gene promoter from Chinese pear (Pyrus pyrifolia)

Abstract: The 5′‐flanking region of the S 12-, S 13-, S 21-RNase with a length of 854bp, 1448bp and 1137bp were successfully isolated by TAIL-PCR from genomic DNA from ‘Jinhua’, ‘Maogong’ (Pyrus pyrifolia) and ‘Yali’ (Pyrus bretschneideri) genomic DNA. Sequence alignment and analysis of S 13-, S 12-, S 21-RNase gene promoter sequences with S 2-, S 3-, S 4-, S 5-RNase 5′-flanking sequences indicated that a homology region of about 240bp exists in the regions just upstream of the putative TATA boxes of the seven Chinese/Japanese pear S-RNase genes. Phylogenetic tree suggests that the homology region between the Chinese/Japanese pear and apple S-RNase gene promoter regions reflects the divergence of S-RNase gene was formed before the differentiation of subfamilies. Full length and a series of 5′-deletion fragments-GUS fusions were constructed and introduced into Arabidopsis thaliana plants. GUS activity were detected in S 12 -pro-(1 to 5)-GUS‐pBll01.2 transgenic pistils and progressively decreased from S 12 -pro-1-GUS-pBI l01.2 to S 12 -pro-5-GUS-pBll01.2. No GUS activity was detected in S 12 -pro-6-GUS-pBll01.2 transgenic pistil and other tissues of non-transformants and all transgenic plants. The result suggested S 12-RNase promoter is pistil specific expression promoter. [Copyright &y& Elsevier]