The Populus canescens (Populus tremula x Populus alba) caffeoyl shikimate esterase 2 hairpin RNA is comprised of a sequence with homology to the first 120 base pairs of the caffeoyl shikimate esterase 2 coding sequence. Caffeoyl shikimate esterase is involved in the biosynthesis of the monolignols that form the basis of the lignin polymer. Silencing of caffeoyl shikimate esterase resulted in reduced lignin deposition and increased cellulose content in the cell wall.

In Arabidopsis thaliana, caffeoyl shikimate esterase enzyme is involved in the biosynthesis of lignin. It hydrolyzes caffeoylshikimate into caffeate and shikimate. Together with 4-coumarate--CoA ligase, it acts on an alternative reaction for the formation of caffeoyl-CoA and bypasses the second reaction of shikimate O-hydroxycinnamoyltransferase. It also accepts also 4-coumaroylshikimate as substrate, but with lower activity.