PubMed · 2026-04-21
Scientists identified two key enzymes in liverwort that explain how the plant makes a rare class of protective compounds called bis(bibenzyls). By knocking out one enzyme with gene editing, they confirmed the exact biochemical route the plant uses to build these natural defenses.
Two enzymes — Mp4CL3 and MpDBR1 — together form the biochemical route from p-coumaric acid to dihydro-p-coumaroyl-CoA, a key building block for bis(bibenzyl) compounds in liverwort.
MpDBR1 reduces the double bond specifically in p-coumaroyl-CoA (not in p-coumaric acid directly), resolving a long-standing question about the order of steps in the pathway.
CRISPR/Cas9 knockout of MpDBR1 caused a significant reduction in bis(bibenzyl) content, genetically confirming its essential role in the biosynthetic pathway.
