Characterisation of Lignin from CAD and OMT DeficientBm Mutants of Maize

✍ Scribed by Provan, Gordon J; Scobbie, Lorraine; Chesson, Andrew

• Publisher: John Wiley and Sons
• Year: 1997
• Tongue: English
• Weight: 242 KB
• Volume: 73
• Category: Article
• ISSN: 0022-5142
• DOI: 10.1002/(sici)1097-0010(199702)73:2<133::aid-jsfa696>3.0.co;2-q

✦ Synopsis

Internodes of the maize cell line W401 and and mutants bm 1 bm 3 expressed in W401 were harvested 5 days after anthesis (A5) and at silage (S) stage. The normal maize had a higher total phenolic (TP) content (80É5È 90É5 g kg~1 cell wall DM) than both and mutants (74É4È86É4 and 66É0È bm 1 bm 3 84É2 g kg~1 cell wall DM, respectively). TP were inversely related to cellulase digestibility with values of 85É4È91É5, 89É3È92É1 and 91É3È94É1% for normal, bm 1 and Marked di †erences in p-coumaric acid concentrations were found bm 3 . ranging from 20É9 to 26É3 g kg~1 cell wall DM for normal, 14É9 to 15É3 g kg~1 for to 10É1 to 14É4 g kg~1 for The ferulate pattern was entirely di †erent bm 1 bm 3 . with the genotype providing the lowest total (9É1È10É7 g kg~1) and etheriÐed bm 1 (1É9È2É3 g kg~1) values. Although the contained more total ferulate (11É5È bm 3 13É1 vs 10É9È11É7 g kg~1), the normal variety had a signiÐcantly greater amount of etheriÐed ferulate (2É8È3É4 vs 3É2È4.1 g kg~1) implying a greater extent of cross-linking between wall polymers. Recovery of guaiacyl and syringyl residues was greatest in the normal maize with the occupying the middle position bm 1 between the two extremes. Calculated S : G ratios from 4 M NaOH digestion and NMR were in good agreement with the normal line giving the highest ratio, bm 1 intermediate and the lowest. Colorimetric analysis revealed a large increase bm 3 in the aldehyde content of the in situ lignin compared to normal and bm 1 bm 3 genotypes although NMR failed to reveal signiÐcant numbers of aldehydic resonances.