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Characterisation of Lignin from CAD and OMT Deficient Bm Mutants of Maize
Author(s) -
Provan Gordon J,
Scobbie Lorraine,
Chesson Andrew
Publication year - 1997
Publication title -
journal of the science of food and agriculture
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.782
H-Index - 142
eISSN - 1097-0010
pISSN - 0022-5142
DOI - 10.1002/(sici)1097-0010(199702)73:2<133::aid-jsfa696>3.0.co;2-q
Subject(s) - lignin , cad , mutant , microbiology and biotechnology , chemistry , biology , botany , biochemistry , gene
Internodes of the maize cell line W401 and bm 1 and bm 3 mutants 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 (80·5–90·5 g kg ‐1 cell wall DM) than both bm 1 and bm 3 mutants (74·4–86·4 and 66·0– 84·2 g kg ‐1 cell wall DM, respectively). TP were inversely related to cellulase digestibility with values of 85·4–91·5, 89·3–92·1 and 91·3–94·1% for normal, bm 1 and bm 3 . Marked differences in p ‐coumaric acid concentrations were found ranging from 20·9 to 26·3 g kg ‐1 cell wall DM for normal, 14·9 to 15·3 g kg ‐1 for bm 1 to 10·1 to 14·4 g kg ‐1 for bm 3 . The ferulate pattern was entirely different with the bm 1 genotype providing the lowest total (9·1–10·7 g kg ‐1 ) and etherified (1·9–2·3 g kg ‐1 ) values. Although the bm 3 contained more total ferulate (11·5–13·1 vs 10·9–11·7 g kg ‐1 ), the normal variety had a significantly greater amount of etherified ferulate (2·8–3·4 vs 3·2–4.1 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 bm 1 occupying the middle position 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 bm 3 the lowest. Colorimetric analysis revealed a large increase in the aldehyde content of the in situ bm 1 lignin compared to normal and bm 3 genotypes although NMR failed to reveal significant numbers of aldehydic resonances. © 1997 SCI.