BIA, UR 1268, INRA, 44300 Nantes, France.
GDEC, UMR 1095, INRA Université Clermont Auvergne, 63000 Clermont-Ferrand, France.
Carbohydr Polym. 2019 Nov 15;224:115063. doi: 10.1016/j.carbpol.2019.115063. Epub 2019 Jul 12.
In wheat endosperm, mannan, is poorly documented. Nevertheless, this hemicellulosic polysaccharide might have a determinant role in wheat grain development since, in Arabidopsis thaliana, mutants with a reduced amount of mannan show an altered seed development. In order to gain knowledge about mannan in wheat, we have determined its biochemical structure in wheat endosperm where mannose content is about 0.2% (dry weight basis). We developed a method of enzymatic fingerprinting and isolated mannan-enriched fractions to decipher its fine structure. Although it is widely accepted that the class of mannan present in grass cell walls is glucomannan, our data indicate that, in wheat endosperm, this hemicellulose is only represented by short unsubstituted chains of 1,4 linked D-mannose residues and is slightly acetylated. Our study provides information regarding the interactions of mannan with other cell wall components and help to progress towards the understanding of monocot cell wall architecture and the mannan synthesis in wheat endosperm.
在小麦胚乳中，甘露聚糖的研究较少。然而，这种半纤维素多糖可能在小麦籽粒发育中具有决定性作用，因为在拟南芥中，甘露聚糖含量降低的突变体表现出种子发育的改变。为了了解小麦中的甘露聚糖，我们已经确定了其在小麦胚乳中的生化结构，其中甘露糖含量约为 0.2%（干重基础）。我们开发了一种酶指纹图谱方法，并分离了富含甘露聚糖的级分，以解析其精细结构。尽管人们普遍认为存在于禾本科细胞壁中的甘露聚糖属于葡甘露聚糖，但我们的数据表明，在小麦胚乳中，这种半纤维素仅由 1,4 连接的 D-甘露糖残基组成的短未取代链表示，并且略有乙酰化。我们的研究提供了有关甘露聚糖与其他细胞壁成分相互作用的信息，并有助于深入了解单子叶植物细胞壁结构和小麦胚乳中甘露聚糖的合成。
