Molecular Characterization And Evoluational Analyses Of X-type High-molecular-weight Glutenin Promoters From Diploid Species In Triticeae

There are many novel HMW-GS alleles in Triticeae species, which play an important role in improving flour quality of common wheat. The sequences of x-type high-molecular-weight glutenin promoters (x-HGP) from different genomes in Triticeae were cloned and analyzed. The results were outlined as following.1. The x-HGP sequences were isolated from nine species, and the length of entire x-HGP sequences varied from 865 to 927 bp. The x-HGP sequences from nine species shared higher similarity with those from known sequences of x-HGP. Comparative analysis of promoter sequences revealed that the x-HGP of nine species contained all the conserved regulatory elements, including TATA-box, E-motif, N-motif and enhancer.2. Multiple sequence alignment showed that although the sequences of x-HGP are conserved, variations were also observed. Several insertions of lbp,12bp and 7bp were found in the sequences of Secale cereale, Thinopyrum bessarabicum, Secale sylvestre and Secale strictum.3. The neighbour-joining tree was conducted by using x-HGP sequences. The resulted tree indicated that the five species from Aegilops and Henrardia were included one group and other four species from Secale and Thinopyrum were included the other group. These results indicated that they could well elucidate the evolutional relationships of diploid species in Triticeae. Therefore, the sequence of x-HGP is an suitable candidate gene for phylogenetic analysis of Triticeae.