Fig. 6.

Proportions of sugar yields and resistant material from poplar variants with or without catalytic delignification to acid hydrolysis after swelling and gelatinization in TFA. Freeze-dried materials of untreated (a) and catalytically delignified (CDL) (b), low-temperature swollen in TFA without (c) and with CDL treatment (d), and TFA-swollen gels heated to 55°C for 5h without (e) or with CDL treatment (f) were hydrolyzed in 2 M TFA at 120°C for 90 min. Cellulose was determined in insoluble residue (in gray), and monosaccharides, glucose (in blue) and xylose (in green), were determined after conversion to alditol acetate derivatives and separation by GC-MS. WT = (Populus tremula × P. alba cv. INRA 717-1B4), high S-lignin = pAtC4H:AtF5H1, high G-lignin = pAtC4H:PtF5H2 RNAi, and high OH-G-lignin = p35S:PtCOMTa RNAi. Values are the means ± S.D. of three determinations of weight % of carbohydrate in the insoluble material remaining after each extraction