title: Genetic diversity associated with variation in silage corn digestibility for three O-methyltransferase genes involved in lignin biosynthesis.
abstract: Polymorphisms within three candidate genes for lignin biosynthesis were investigated to identify alleles useful for the improvement of maize digestibility. The allelic diversity of two caffeoyl-CoA 3-O-methyltransferase genes, CCoAOMT2 and CCoAOMT1, as well as that of the aldehyde O-methyltransferase gene, AldOMT, was evaluated for 34 maize lines chosen for their varying degrees of cell wall digestibility. Frequency of nucleotide changes averaged one SNP every 35 bp. Ninety-one indels were identified in non-coding regions and only four in coding regions. Numerous distinct and highly diverse haplotypes were identified at each locus. Numerous sites were in linkage disequilibrium that declined rapidly within a few hundred bases. For F4, an early flint French line with high cell wall digestibility, the CCoAOMT2 first exon presented many non-synonymous polymorphisms. Notably we found an 18-bp indel, which resembled a microsatellite and was associated with cell wall digestibility variation. Additionally, the CCoAOMT2 gene co-localized with a QTL for cell wall digestibility and lignin content. Together, these results suggest that genetic diversity investigated on a broader genetic basis could contribute to the identification of favourable alleles to be used in the molecular breeding of elite maize germplasm.
authors.affiliation: Unité de Génétique et d'Amélioration des Plantes Fourragères, INRA, Route de Saintes, 86600 Lusignan, France. cguillet@rsvs.ulaval.ca
authors.forename: C
authors.initials: C
authors.lastname: Guillet-Claude
authors.forename: C
authors.initials: C
authors.lastname: Birolleau-Touchard
authors.forename: D
authors.initials: D
authors.lastname: Manicacci
authors.forename: M
authors.initials: M
authors.lastname: Fourmann
authors.forename: S
authors.initials: S
authors.lastname: Barraud
authors.forename: V
authors.initials: V
authors.lastname: Carret
authors.forename: J P
authors.initials: JP
authors.lastname: Martinant
authors.forename: Y
authors.initials: Y
authors.lastname: Barrière
mesh_terms: D000483:Alleles; D019943:Amino Acid Substitution; D000821:Animal Feed / Q000032:analysis; D000818:Animals; D001483:Base Sequence; D002417:Cattle; D002473:Cell Wall / Q000378:metabolism; D002874:Chromosome Mapping; D018744:DNA, Plant / Q000235:genetics; D004063:Digestion; D017343:Genes, Plant; D014644:Genetic Variation; D008031:Lignin / Q000096:biosynthesis*; D015810:Linkage Disequilibrium; D008780:Methyltransferases / Q000235:genetics* / Q000378:metabolism; D011110:Polymorphism, Genetic; D011401:Promoter Regions, Genetic; D011995:Recombination, Genetic; D003313:Zea mays / Q000201:enzymology / Q000235:genetics* / Q000378:metabolism*
chemical_list: D018744:DNA, Plant; D008031:Lignin; D008780:Methyltransferases; C019608:caffeate O-methyltransferase