基于QTL定位和转录组测序解析千里光抗菌性状的分子机制

Data obtained from functional genomics could play crucial important roles in further studies on Chinese traditional medicine. In our previous studies, it has been testified that antibacterial pharmacological trait is contributed to multi genes in Senecio scandens Buch.-Ham. ex D. Don, suggesting that the inaccurate identification of functional genes should be attributed to the complex genetic backgroud in experimental accessions. Accordingly, we successed in construction on expressed sequence tag (EST) library and developments of EST-SSR molecular remarkers. In the current project, the definite relationships between loci of genes of antibacterial phenotypes and their contributions will be applied to explore molecular genetic model of pharmacological traits based on quantitative trait loci (QTL). And then, the functional genomics of pharmacological characteristics can be identified using the methods of RNA-seq, sequences of EST-SSRs and gene contributions. Therefore, It will be testified that the false banding patterns are associated with the other characteristics in Chinese traditinal medical plants, based on metabolism association with funcional genomics. These data from our studies will be contributed to selection of novel Functional genomics in Senecio scandens Buch.-Ham. Ex D. Don. Moreover, those parameters resulted from this project will provide the accurate screening of genome with application in comparison on functional genomics, evaluating genetic diversity, determining the sampled eco-geographic origins and improving breeding quality in the Compositae species.

开展中药材药用品质功能基因组学研究是推进中药现代化的重要途径。我们已证实，千里光抗菌作用是多基因控制的数量性状，并推测复杂的遗传背景是影响功能基因组准确鉴定的重要因素。为证实这一猜想，我们首次构建了千里光全长cDNA文库并成功开发EST-SSR分子标记，以此为基础，本项目将通过数量性状座位作图(QTL)显示千里光抗菌性状基因位点的染色体位置、贡献率和表型效应，结合基因差异表达谱和EST-SSRs序列信息，解析千里光抗菌性状的分子机制。本项目从转录组学和代谢组学的角度有效整合千里光抗菌性状功能基因组的研究方法，有望为高等植物功能基因的筛选排除“假阳性”提供新思路；同时，EST数据库的建立也为菊科近缘药用植物功能基因类比、遗传多样性评价、种质资源遗传改良提供分子生物学依据。

千里光是具有良好开发前景的抗菌中草药，其抗菌作用表现为多基因控制的数量性状。目前，开展中药材药用品质功能基因组学研究是推进中药现代化的重要途径，“假阳性”是功能基因筛查的常见障碍，分子机制尚不明确。本项目的研究结果表明，遗传背景是影响千里光抗菌性状功能基因组准确鉴定的重要因素之一，此外，我们利用全长cDNA文库并开发的EST-SSR分子标记，通过数量性状座位作图(QTL)显示千里光抗菌性状基因位点的染色体位置、贡献率和表型效应，初步实现药用植物代谢组学和功能基因组学的有机整合，为目标性状与功能基因之间的联系提供了试验基础；同时，EST数据库的建立也为菊科近缘药用植物功能基因类比、遗传多样性评价、种质资源遗传改良提供分子生物学依据。然而，转录组测序和QTL筛查抗菌性状基因组时发现，多个位点的基因差异表达谱与基因位点贡献率并不吻合，这亟待蛋白组学和代谢组学数据对该基因组的功能进行验证，进而评价该技术体系对高等植物数量性状基因组筛查的准确性。