Isolation and characterisation of three 4-coumarate : CoA-ligase homologue cDNAs from perennial ryegrass (Lolium perenne)

4-Coumarate : CoA-ligase (4CL, EC 6.2.1.12) catalyses the conversion of hydroxycinnamic acids to hydroxycinnamoyl-CoA thioesters, precursors for a variety of phenylpropanoid biosynthetic derivatives including lignins, flavonoids and phytoalexins. Three 4CL homologue cDNAs were isolated from a perennial ryegrass cDNA library. Sequence analysis indicates that Lp4CL2 and Lp4CL3 correspond to class I type 4CLs, while Lp4CL1 is most related to class II type 4CLs. Southern hybridisation analysis suggests that Lp4CL1, Lp4CL2 and Lp4CL3 each belong to a small multigene family. Northern hybridisation analysis revealed constitutive expression of the Lp4CL genes in perennial ryegrass. Lp4CL1 and Lp4CL3 were mapped to perennial ryegrass linkage groups 2 and 6 respectively.