Cytochrome P450 which catalyzes 3'-hydroxylation of p-coumaric esters of shikimic/quinic acids to form lignin monomers. Can use p-coumarate, p-coumaraldehyde, p-coumaroyl methyl ester, 5-O-(4-coumaroyl) D-quinate and 5-O-(4-coumaroyl) shikimate as substrates, but not p-coumaryl alcohol, p-coumaroyl CoA, 1-O-p-coumaroyl-beta-D-glucose, p-hydroxy-cinnamyl alcohol, cinnamate, caffeate or ferulate. Has a weak activity on tri(p-coumaroyl)spermidine, but none on triferuloylspermidine. Hydroxylates preferentially the 5-O-isomer, but can also convert the 4-O- and 3-O-isomers with a lower efficiency. Involved in the biosynthesis of the coumarins scopoletin and scopolin. Essential for the biosynthesis of lignin. kcat is 612 min(-1) with 5-O-(4-coumaroyl) shikimate as substrate. kcat is 399 min(-1) with 5-O-(4-coumaroyl) quinate as substrate. Highly expressed in stems, roots and siliques. Detected in leaves flowers and seedlings. Highest expression detected in differentiating xylem. Up-regulated by wounding. Dwarf. 91% and 97% reduction of the levels of scopoletin and scopolin respectively, but increased levels of skimmin, the beta-glucoside of umbelliferone. Altered lignin composition and increased susceptiblity to fungal colonization. Belongs to the cytochrome P450 family. Truncated N-terminus.