Quadram Institute Bioscience, Norwich Research Park, Colney, Norwich NR4 7UA, United Kingdom.
Department of Biology, University of York, Heslington, YO10 5DD, United Kingdom.
Proc Natl Acad Sci U S A. 2017 Jun 27;114(26):6860-6865. doi: 10.1073/pnas.1619033114. Epub 2017 Jun 12.
Genetic improvement of the plant cell wall has enormous potential to increase the quality of food, fibers, and fuels. However, the identification and characterization of genes involved in plant cell wall synthesis is far from complete. Association mapping is one of the few techniques that can help identify candidate genes without relying on our currently incomplete knowledge of cell wall synthesis. However, few cell wall phenotyping methodologies have proven sufficiently precise, robust, or scalable for association mapping to be conducted for specific cell wall polymers. Here, we created high-density carbohydrate microarrays containing chemically extracted cell wall polysaccharides collected from 331 genetically diverse cultivars and used them to obtain detailed, quantitative information describing the relative abundance of selected noncellulosic polysaccharide linkages and primary structures. We undertook genome-wide association analysis of data collected from 57 carbohydrate microarrays and identified molecular markers reflecting a diversity of specific xylan, xyloglucan, pectin, and arabinogalactan moieties. These datasets provide a detailed insight into the natural variations in cell wall carbohydrate moieties between genotypes and identify associated markers that could be exploited by marker-assisted breeding. The identified markers also have value beyond for functional genomics, facilitated by the close genetic relatedness to the model plant Together, our findings provide a unique dissection of the genetic architecture that underpins plant cell wall biosynthesis and restructuring.
遗传改良植物细胞壁具有显著提高食物、纤维和燃料质量的潜力。然而，参与植物细胞壁合成的基因的鉴定和特征描述远未完成。关联作图是为数不多的可以帮助识别候选基因的技术之一，而无需依赖我们目前对细胞壁合成的不完全了解。然而，很少有细胞壁表型测定方法被证明足够精确、稳健或可扩展，无法针对特定细胞壁聚合物进行关联作图。在这里，我们创建了包含从 331 个遗传多样性品种中提取的化学细胞壁多糖的高密度碳水化合物微阵列，并使用它们获得了详细的定量信息，描述了所选非纤维素多糖键和一级结构的相对丰度。我们对来自 57 个碳水化合物微阵列的收集的数据进行了全基因组关联分析，并鉴定了反映各种木聚糖、木葡聚糖、果胶和阿拉伯半乳聚糖部分的分子标记。这些数据集深入了解了基因型之间细胞壁碳水化合物片段的自然变异，并确定了可以通过标记辅助育种利用的相关标记。所鉴定的标记除了在功能基因组学方面具有价值外，由于与模式植物 具有密切的遗传关系，也具有价值。总之，我们的研究结果提供了对植物细胞壁生物合成和重构基础遗传结构的独特剖析。
