Phytohormone levels in monolignol pathway mutants. Phytohormone levels are shown in lignin biosynthesis pathway mutants as determined by UHPLC. A, SA. B, ABA. C, JA. D, MeJA. Fresh samples were prepared from aboveground whole tissue from 10d seedlings (black bars) and mature stem tissue (gray bars). Data are means ± sd (n = 3 biological replicates) of results from one allele for each target gene. WT, Wild type. *, 0.01 < P < 0.05; **, 0.001 < P < 0.01; and ***, 0.001 > P, Student’s t test.