Sequences and expression pattern of cinnamyl alcohol dehydrogenase gene and over-expression and detection of CAD4 enzymatic activity of poplar in vitro
The 19 CAD genes of poplar screened by bioinformatics are clustered into 3 groups.Analysis of their sequences showed that the expansion of CAD gene family in Populus was resulted from a recent whole-genome doubling and tandem replication.There are 6 paralogs in CAD gene family of Populus and Arabidopsis evolved under the purifying selection.The 19 CAD genes are expressed in all tissues of Populus.PoptrCAD17,PoptrCAD4,PoptrCAD10 and PoptrCAD7 expressed highly while the other CAD genes expressed at a lower level.Expression of the CAD genes in the same group varied with the same trends.CAD gene cloned in this research was PoptrCAD4.The catalytic activity of the CAD enzyme over-expressed in vitro were high,with the substrate preference of sinapyl alcohol.