Molecular Cloning, sequence analysis and expression studies of a novel GAmyb homologous gene, hvmyb

Using a known GAmyb gene as the probe, two fully identical clones were isolated from barley aleurone cDNA library. Sequence analysis showed that their 5′ termini are highly homologous to the 3′ termini of GAmyb (97% ) and their 3′ termini share no significant homology with any myb genes. Therefore, the deduced protein may hold intact putative GAmyb activation domain but lack the normal DNA-binding domain, Northern blot reveals that hvmyb expression in barley alcurone layers is strongly up-regulated by gibberellin (GA) and down-regulated by abscisic acid (ABA). The tissue- and developmental-stage-specificity of hvmyb was also found, which was only expressed in barley aleurone cells and dropped to non-detectable level soon after germination.