Poster Title: The Cinnamyl Alcohol Dehydrogenase gene family regulates lignin content in Populus
Authors: Abdelali Barakat, Agnieszka Bagniewska-Zadworna, Alex Choi, and John E. Carlson
Poster Abstract: The Cinnamyl alcohol dehydrogenase (CAD) enzyme catalyzes the last step of the synthesis of phenolic monomers which plants use to build the cell wall lignin heteropolymer. CAD has been studied extensively, however, no complete phylogenetic analysis of this gene family has yet been published. Moreover, most of the expression and functional analyses have been done with genes from Arabidopsis and rice rather than trees. We analyzed the phylogeny of CAD and found evidence of two main classes of CAD represented by sequences from all seed plant species. Analysis of the genome organization of CAD showed that most CAD genes were duplicated and are still in conserved positions on the chromosomes. We analyzed the expression of CAD genes in various tissues from non-stressed and herbivore stressed Populus plants. We found that while two genes are involved in lignin biosynthesis in xylem, the other CAD genes may play a role in plant defense against herbivores as well as other biotic stresses in poplar.