Vol 42(2008) N 1 p. 56-63;
Z.X. Han1,2, G. Qian1,3, F. Wu1, Z.F. Pan1, G.B. Deng1, M.Q. Yu1
Sequences variation and classification of B-hordein genes in hull-less barley from the Qinghai-Tibet Plateau1Chengdu Institute of Biology, the Chinese Academy of Sciences, Chengdu, Sichuan, 610041, China
2Graduate School of the Chinese Academy of Sciences, Beijing, 100039, China
3Department of Biology, Zunyi Medical College, Zunyi, 563003, China
Received - 2007-01-22; Accepted - 2007-04-23
The goal of this study is to understand the evolution relationship of the members of the B-hordein gene family in hull-less barley by analysis of their structure and to explore their utility in grain quality improvement. Six copies of the B-hordein gene (Hn1-Hn3, Hn7-Hn9) were cloned from six hull-less barley cultivars collected from Qinghai-Tibet Plateau and molecularly characterized. Comparison of their predicted polypeptide sequences with the published data suggested that they all share the same basic protein structures. In addition, we found that the C-terminal end sequences of all B-hordeins shared a similar feature. In the six clones and the other three published genes (Hn4, Hn5, and Hn6) from hull-less barley, Hn2 and Hn7 contained the identical C-terminal end sequence DIMPVDFWH. Hn3, Hn4, Hn5, Hn8 and Hn9 also shared the common sequence DIMPPDFWH, which was similar to that of a B-hordein reported previously. Both Hn1 and Hn6 exhibited differences in their C-terminal end sequences, and they clustered into different subgroups. The B-hordeins with identical C-terminal end sequences were clustered into the same subgroup, so we believe that B-hordein gene subfamilies possibly can be classified on the basis of the conserved C-terminal end sequences of predicted polypeptide. Phylogenetic analysis also indicated that there is a relatively weak identity between our predicted B-hordeins and those reported from H. chilense and H. brevisubulatum. All of our nine predicted B-hordeins were clustered together and other B-hordeins formed another cluster. The possible use of these genes in relation to barley quality is discussed.
hull-less barley (Hordeum vulgare subsp. vulgare), B-hordeins, C-terminal domain evolution, multigene family