Metabolomics-based post-genome science in plants

组学综合分析可以为基因功能鉴定和基因-代谢物和/或代谢物-代谢物网络的精确信息提供线索。我们在拟南芥中进行了结合代谢组和转录组的功能基因组计划。氮和硫的营养胁迫导致了代谢组分的全球变化，这可能与基因表达的调控有关，表明基因到代谢物网络的存在，特别是在硫代葡萄糖苷的生物合成中。花青素高产拟南芥品系的全面基因表达和代谢产物谱揭示了负责花青素修饰和储存的新基因的功能。通过对T-DNA插入线和重组蛋白的分析，鉴定了这些基因的功能。通过扩展这一策略，我们使用了一个公开可用的转录组数据库，用于未知基因和网络的功能鉴定。在这些共表达分析的基础上，构建了共表达基因的模型，特别是代谢途径，从而推测这些基因的功能，然后用反向遗传学策略进行验证。利用代谢组分析平台利用质谱仪对感兴趣基因的敲除突变体进行广泛的代谢谱分析。对突变体的详细代谢物分析揭示了代谢物类型的变化，表明了基因功能。这种代谢组和转录组的综合分析策略不仅适用于模式植物拟南芥的基因功能破译，也适用于预计富含多种植物化学物质的未知植物。

Integrated analysis of omics can provide the clues for identification of gene function and precise information about gene-to-metabolite and/or metabolite-to-metabolite networks. We ran the functional genomics project combining metabolome and transcriptome in Arabidopsis thaliana. Nutritional stress of nitrogen and sulfur resulted in global change of metabolome that could be correlated with the modulation of gene expression, indicating the presence of gene-to-metabolite networks, in particular, in glucosinolate biosynthesis. The comprehensive gene expression and metabolite profiles of anthocyanin overproducing Arabidopsis lines revealed the function of novel genes that are responsible for modification and storage of anthocyanins. The function of those genes was identified by analysis of the T-DNA insertion lines and recombinant proteins. By expanding this strategy, we used a transcriptome database publicly available for functional identification of unknown genes and networks. Upon these co-expression analyses, the models of co-expressed genes in particular metabolic pathways were constructed, leading to speculation of functions of those genes followed by confirmation with reverse genetics strategy. Extensive metabolic profiling of the knockout mutants of genes of interest was performed by a metabolome-analytical platform employing mass spectrometry. Detailed metabolite analysis of the mutants revealed the changes in metabolo-types, indicating the gene functions. This strategy of integrated analysis of metabolome and transcriptome is applicable to decipher the function of genes not only for a model plant A. thaliana but also for unexplored plants expected rich with a variety of phychemicals.