Figure 4.

Analysis of mucilage composition using Fourier Transform Infrared analysis (FTIR) showed differences in cellulose, hemicelluloses and pectin peaks. FTIR was performed on the ammonium oxalate extracted mucilage for structural changes. Analysis of subtraction plot between wild type and cesa2–1cesa5–1cesa9–1 triple mutant showed differences in peaks related to cellulose (898, 930, 1033, 1058, 1120 and 1162, hemicellulose (WN-1078 and 945) and pectin WN-989, 1017, 1122, 1144 and 1150). Samples were prepared by dissolving exactly 2mg mucilage pellet in 50 μL water with 20mg of KBr, the overnight dried (50°) mixture was stored in a desiccator. Pellets for FT-IR were made by 2mg mucilage-KBr mixture with 23 mg of fresh KBr, pressed into 7-mm pellets and collected spectra for wild type and mutants using a Thermo Nicolet Nexus 470 spectrometer (ThermoElectric Corporation, Chicago, IL) over the range 4,000–800 cm⁻¹. For each spectrum, 200 scans were performed at a resolution of 8 cm⁻¹. Subtraction plot between wild type and triple mutant was made using OMNIC software (Thermo Nicolet, Madison, WI) and spectral differences were cross referenced with Kacuráková et al.²⁴ to identify peaks linked to cellulose (indicated by black caret), xyloglucan (black line) and pectin (asterisk and red caret).