Phenolic 3-hydroxylases in land plants: biochemical diversity and molecular evolution




Alber, Annette Veronika

Journal Title

Journal ISSN

Volume Title



Plants produce a rich variety of natural products to face environmental constraints. Enzymes of the cytochrome P450 CYP98 family are key actors in the production of phenolic bioactive compounds. They hydroxylate phenolic esters for lignin biosynthesis in angiosperms, but also produce various other bioactive phenolics. We characterized CYP98s from a moss, a lycopod, a fern, a conifer, a basal angiosperm, a monocot and from two eudicots. We found that substrate preference of the enzymes has changed during evolution of land plants with typical lignin-related activities only appearing in angiosperms, suggesting that ferns, similar to lycopods, produce lignin through an alternative route. A moss CYP98 knock-out mutant revealed coumaroyl-threonate as CYP98 substrate in vivo and showed a severe phenotype. Multiple CYP98s per species exist only in the angiosperms, where we generally found one isoform presumably involved in the biosynthesis of monolignols, and additional isoforms, resulting from independent duplications, with a broad range of functions in vitro



cytochrome P450, land plant evolution, monolignol, CYP98, C3'H, Populus trichocarpa, Physcomitrella patens, phenolic conjugate, hydroxycinnamic, lignin, coumaroyl-threonate, coumaroyl-shikimate