“…Angiosperm lignins are mainly composed of guaiacyl (G), syringyl (S), and minor amounts of p-hydroxyphenyl (H) units that are derived from the monolignols coniferyl, sinapyl, and p-coumaryl alcohol, respectively ( Figure 1). Monolignols are synthesized from phenylalanine via the general phenylpropanoid and monolignol biosynthetic pathways ( Figure 1) (Boerjan et al, 2003;Vanholme et al, 2008;Bonawitz and Chapple, 2010;Vanholme et al, 2010Vanholme et al, , 2012aVanholme et al, , 2012b. These pathways are most probably active in the cytoplasm, as the three P450 enzymes involved in monolignol biosynthesis have been localized to the outer surface of the endoplasmic reticulum, facing toward the cytosol (Ro et al, 2002;Li et al, 2008;Bassard et al, 2012;Sundin et al, 2014).…”