Fig. 6

Characterization of lignin and hydroxycinnamates in wild type and Bdlsi1-1 mutant plants. The concentrations of acetyl bromide soluble lignin were quantified in the wild-type and the Bdlsi1-1 sampled at the ripening growth stage (a) and maturity (b). Results are presented as mean values (± SD, n  ≥  3), asterisk indicates statistically significant difference between the wild-type and the mutant plants (p ≤ 0.05), as assessed by one-way ANOVA followed by Tukey’s HDS post hoc test. c Lignin distribution in transverse sections from wild-type and Bdlsi1-1 internodes sampled at the ripening stage was visualized with phloroglucinol staining (Wiesner method) (colour from light orange to red). Scale bars: 50 μm. Composition of monolignols was characterized in mature straw (d) and entire shoots (e) using analytical pyrolysis GC/MS. Data are presented as monolignol frequency (%), which is interpreted as an abundance of given monolignols in relation to all released monolignols. The composition of hydroxycinnamic acids in mature straw (f) and entire shoots (g) was quantified analogously to the lignin composition. Mean values (± SD, n ≥ 2) are presented. ovb outer vascular bundles, ivb inner vascular bundles, if interfascicular region, bs bundle sheaths, S syringyl unit, G guaiacyl unit, p-hydroxyphenyl unit, FA ferulic acid, p-CA p-coumaric acid, SA sinapic acid