Isolation and characterisation of three cinnamyl alcohol dehydrogenase homologue cDNAs from perennial ryegrass (Lolium perenne L.)

Three cinnamyl alcohol dehydrogenase (CAD, EC 1.1.1.195) homologue cDNAs (LpCAD1, LpCAD2 and LpCAD3) were isolated and characterised in perennial ryegrass (Lolium perenne). Sequence analysis revealed a partial LpCAD3 clone is highly homologous to typical monocot CAD cDNAs while full-length LpCAD1 and LpCAD2 cDNAs show lower homology to known CAD cDNAs. Northern hybridisation analysis revealed LpCAD1 and LpCAD3 transcripts in lignifying tissues while LpCAD2 was uniquely abundant in stem tissue. All three CAD cDNAs are upregulated in response to mechanical wounding stimulus. Southern hybridisation analysis suggested that LpCAD3 is a single copy gene within the Lolium genome while LpCAD1 and LpCAD2 each belong to a small gene family.