Cell Wall Construction

Abstract

Plant Science![Figure][1] CREDIT: JING-KE WENG Lignin, a heterogeneous polymer built from p -hydroxycinnamyl monomers, provides the stiffness in woody tissues of vascular plants. The resiliency of lignin may be useful to a tall tree, but it is an obstacle in the extraction of sugars from plant tissues that are used as biofuels. Angiosperms use a larger set of subunits—featuring monomers in which hydroxylation at both meta positions has occurred—to make lignin than do most plants in the lycophyte lineage, which diverged from the angiosperm lineage 400 million years ago. Weng et al. have identified a cytochrome P450 enzyme from the lycophyte Selaginella that bears limited similarity to angiosperm enzymes, and when the Selaginella enzyme was introduced into the angiosperm Arabidopsis , a new form of lignin was detected. These results suggest that the enzymatic diversity of the broader plant kingdom might be informative for taming recalcitrant biosynthetic pathways in potential biofuel crops. Plant Cell 22 , 10.1105/tpc.109.073528 (2010). [1]: pending:yes