Figure 2

Correlations between lignin content, wall-bound phenolics and SSF ethanol yield. (a) The content of ester-linked, ether-linked and total wall-bound p-coumaric and ferulic acids in the cell wall residues (CWR) of switchgrass whole tillers. (b) Lignin composition of control and PvMYB4-OX switchgrass whole tillers determined by thioacidolysis. Ctrl: control lines; S, syringyl unit; G, guaiacyl unit; H, p-hydroxyphenyl unit. (c-f) Correlations with SSF ethanol yield without pretreatment. (c) lignin content. (d) wall-bound p-coumaric acid. (e) ether-lined ferulic acid. (f) wall-bound p-CA/FA ratio. All data are means ± SE (n = 3). The letters indicates significant differences of total lignin content at the p < 0.05 level. Mean comparisons, based on mean separation test results, cannot be compared across variables in Figure 2a.