Genome-wide analysis of the gene family reveals two genes in oil palm.

Unlabelled: Cinnamyl alcohol dehydrogenase (CAD) is the key enzyme for lignin biosynthesis in plants. In this study, genome-wide analysis was performed to identify genes in oil palm (). Phylogenetic analysis was then conducted to select the s. The genes and their respective 5' flanking regions were cloned and analysed. Their expression profiles were evaluated in various organs using RT-PCR. Seven genes (-7) were identified and divided into four phylogenetic groups. EgCAD1 and EgCAD2 display high sequence similarities with other CADs and possess all the signature motifs of the CAD. They also display similar 3D protein structures. Gene expression analysis showed that was expressed most abundantly in the root tissues, while was expressed constitutively in all the tissues studied. possesses only one transcription start site, while has five. Interestingly, a TC microsatellite was found in the 5' flanking region of . The 5' flanking regions of and contain lignin-associated regulatory elements i.e. AC-elements, and other defence-related motifs, including W-box, GT-1 motif and CGTCA-motif. Altogether, these results imply that and are involved in lignin biosynthesis during the normal development of oil palm and in response to stresses. Our findings shed some light on the roles of the genes in oil palm and pave the way for manipulating lignin content in oil palm through a genetic approach.

Supplementary Information: The online version contains supplementary material available at 10.1007/s13205-022-03208-0.