Isolation, cloning and expression analysis of cinnamyl alcohol dehydrogenase (CAD) involved in phenylpropanoid pathway of Erianthus arundinaceus, a wild relative of sugarcane

Abstract

In this study we have cloned and characterized cinnamyl alcohol dehydrogenase (CAD) involved in phenylpropanoid pathway which can be utilized for biomass modification for improved saccharification efficiency. The full length gene CAD is of 4 kb containing four exons and three introns, among which the exon 1 and 2 of 88 and 116 bp were conserved with sorghum and Miscanthus CADs. The coding region of CAD was identified with 1098 bp open reading frame (ORF), for 365 amino acids. In the PROSITE analysis, a zinc-containing alcohol dehydrogenase signature (GHEVVGEVVEVGPEV) and an NADP-binding domain motif (GLGGLG) was identified, while the motif analysis showed unique signature sequence of “LEPYLA” at 258–264 aa which was absent in the CAD sequences of other crops. This sequence information on CAD from Erianthus a bioenergy crop might be useful for subsequent research on lignin engineering for improved biomass conversion and for unravelling the impact of lignin on cell wall mechanics.