Monosaccharide composition of the cell wall from irx9, irx7 and irx8 plants transformed with IRX9 , IRX7 and IRX8 under the native VND6 and VND7 promoter. Cell wall material (alcohol insoluble residue, AIR) was prepared from fresh stem material, hydrolyzed with trifluoroacetic acid (A and B) or sulfuric acid (C), and analyzed by high-performance anion exchange chromatography. (A) All irx9 transformant lines have significantly reduced xylose content that are similar to those of the irx9 mutant. (B) The irx7 and irx8 transformant lines have intermediary xylose levels compared to the wild type and their respective irx7/irx8 backgrounds. (C) Hexose/pentose ratio in cell walls of transformed irx9 plants. The sugar content in the cell walls was determined after complete hydrolysis with sulfuric acid. All graphs show average ± SD (where (A) and (B) n=4 and (C) n=3) except for irx7 and irx8 mutants where only one replicate was available. * indicates a significant difference in xylose or C6/C5 ratio from the wild type (t-test, p < 0.01).