Fig. 4

a Klason lignin content measured in cell wall residues (CWR) obtained from biomass of switchgrass lines containing the pShOMT::QsuB construct. A line containing the pShOMT::GUS construct was used as control and analyzed thrice since measurements were carried out in three separate batches. Values are means ±SE of four biological replicates (n = 4). Asterisks indicate significant differences from the line containing the pShOMT::GUS construct using the unpaired Student’s t-test (*P < 0.05). b Representative pictures of leaf blade cross-sections stained with phloroglucinol-HCl from lines containing either the pShOMT::GUS or the pShOMT::QsuB construct. Note the reduction of the staining specifically in thick fibers located in the leaf abaxial zone for the pShOMT::QsuB line (red arrows). Scale: black bar = 200 μm