Department of Agronomy, Iowa State University, Agronomy Hall, Ames, IA 50011, USA.
BMC Plant Biol. 2010 Feb 12;10:27. doi: 10.1186/1471-2229-10-27.
OMT (O-methyltransferase) genes are involved in lignin biosynthesis, which relates to stover cell wall digestibility. Reduced lignin content is an important determinant of both forage quality and ethanol conversion efficiency of maize stover.
Variation in genomic sequences coding for COMT, CCoAOMT1, and CCoAOMT2 was analyzed in relation to stover cell wall digestibility for a panel of 40 European forage maize inbred lines, and re-analyzed for a panel of 34 lines from a published French study. Different methodologies for association analysis were performed and compared. Across association methodologies, a total number of 25, 12, 1, 6 COMT polymorphic sites were significantly associated with DNDF, OMD, NDF, and WSC, respectively. Association analysis for CCoAOMT1 and CCoAOMT2 identified substantially fewer polymorphic sites (3 and 2, respectively) associated with the investigated traits. Our re-analysis on the 34 lines from a published French dataset identified 14 polymorphic sites significantly associated with cell wall digestibility, two of them were consistent with our study. Promising polymorphisms putatively causally associated with variability of cell wall digestibility were inferred from the total number of significantly associated SNPs/Indels.
Several polymorphic sites for three O-methyltransferase loci were associated with stover cell wall digestibility. All three tested genes seem to be involved in controlling DNDF, in particular COMT. Thus, considerable variation among Bm3 wildtype alleles can be exploited for improving cell-wall digestibility. Target sites for functional markers were identified enabling development of efficient marker-based selection strategies.
OMT（O-甲基转移酶）基因参与木质素生物合成，这与秸秆细胞壁的可消化性有关。木质素含量的降低是影响饲料质量和玉米秸秆乙醇转化率的重要因素。
分析了 40 个欧洲饲用玉米自交系的 COMT、CCoAOMT1 和 CCoAOMT2 基因编码序列的变异与秸秆细胞壁可消化性的关系，并对来自已发表的法国研究的 34 个系的基因序列进行了重新分析。采用了不同的关联分析方法并进行了比较。通过不同的关联分析方法，共发现 25 个、12 个、1 个、6 个 COMT 多态性位点与 DNDF、OMD、NDF 和 WSC 显著相关。CCoAOMT1 和 CCoAOMT2 的关联分析发现与研究性状显著相关的多态性位点要少得多（分别为 3 个和 2 个）。我们对已发表的法国数据集的 34 个系的重新分析发现 14 个多态性位点与细胞壁可消化性显著相关，其中 2 个与我们的研究一致。从总数量的显著相关 SNPs/Indels 推断出与细胞壁可消化性变异有潜在因果关系的有前途的多态性。
三个 O-甲基转移酶基因座的多个多态性位点与秸秆细胞壁可消化性相关。三个被测试的基因似乎都参与了控制 DNDF，特别是 COMT。因此，可以利用 Bm3 野生型等位基因的巨大差异来提高细胞壁的可消化性。鉴定出了用于功能标记的目标位点，从而能够开发有效的基于标记的选择策略。
