Department of Molecular Genetics/Heterosis, Leibniz Institute of Plant Genetics and Crop Plant Research (IPK) Gatersleben, D-06466 Seeland/OT Gatersleben, Germany.
Department of Breeding Research/Genome Plasticity, Leibniz Institute of Plant Genetics and Crop Plant Research (IPK) Gatersleben, D-06466 Seeland/OT Gatersleben, Germany.
J Exp Bot. 2017 Mar 1;68(7):1655-1667. doi: 10.1093/jxb/erx049.
To gain insight into genetic factors controlling seed metabolic composition and its relationship to major seed properties, an Arabidopsis recombinant inbred line (RIL) population, derived from accessions Col-0 and C24, was studied using an MS-based metabolic profiling approach. Relative intensities of 311 polar primary metabolites were used to identify associated genomic loci and to elucidate their interactions by quantitative trait locus (QTL) mapping. A total of 786 metabolic QTLs (mQTLs) were unequally distributed across the genome, forming several hotspots. For the branched-chain amino acid leucine, mQTLs and candidate genes were elucidated in detail. Correlation studies displayed links between metabolite levels, seed protein content, and seed weight. Principal component analysis revealed a clustering of samples, with PC1 mapping to a region on the short arm of chromosome IV. The overlap of this region with mQTL hotspots indicates the presence of a potential master regulatory locus of seed metabolism. As a result of database queries, a series of candidate regulatory genes, including bZIP10, were identified within this region. Depending on the search conditions, metabolic pathway-derived candidate genes for 40-61% of tested mQTLs could be determined, providing an extensive basis for further identification and characterization of hitherto unknown genes causal for natural variation of Arabidopsis seed metabolism.
为了深入了解控制种子代谢组成及其与主要种子特性关系的遗传因素，本研究利用基于 MS 的代谢组学分析方法，对来自 Col-0 和 C24 品系的拟南芥重组自交系（RIL）群体进行了研究。利用 311 种极性初级代谢物的相对强度，确定了相关的基因组位点，并通过数量性状位点（QTL）作图阐明了它们的相互作用。总共鉴定出 786 个代谢 QTL（mQTL），不均匀地分布在基因组中，形成了几个热点。对于支链氨基酸亮氨酸，详细阐明了 mQTL 和候选基因。相关性研究显示了代谢物水平、种子蛋白质含量和种子重量之间的联系。主成分分析显示样品聚类，PC1 映射到染色体 IV 短臂上的一个区域。该区域与 mQTL 热点的重叠表明存在潜在的种子代谢主调控位点。通过数据库查询，在该区域内鉴定出一系列候选调控基因，包括 bZIP10。根据搜索条件，可确定 40-61%测试 mQTL 的代谢途径衍生候选基因，为进一步鉴定和表征拟南芥种子代谢自然变异的未知基因提供了广泛的基础。
