当归根际微生态对药材品质形成的调控机制研究

Rhizosphere microecology is an important place for information and material exchange among the plant, root exudates and rhizosphere microbes, which is an important factor affecting the quality of medicinal materials, especially for root medicinal materials. In the literature and the previous research, it was confirmed that there were significant differences in the quality of Angelica sinensis under different rhizosphere microecological. Our project proposed to study on the quality formation of Angelica sinensis based on the interaction among the plant, root exudates and rhizosphere microecology in different soil pH. The following works will be carried out: (1) Based on the techniques of metabolomics and soil metagenomics, the metabolic profile of root exudates and rhizosphere microbial characteristic spectrum of Angelica sinensis will be established. (2) From the transcriptome level, its variabilities from secondary metabolites and functional gene expression related to root growth and development of Angelica sinensis will be investigated. (3) A correlation model of potential plant-soil-microbe relation will be constructed, based on the PTRs analysis model and other multivariate statistical methods, and the specific bacteria which are related to quality will be seperated out. (4) Utilize suspended cell, tissue culture, pot experiment and other levels of experimental verification to search for signal factors in micro-ecological regulation of Angelica quality and functional genes’ metabolism as well as regulation pathway from transcriptome and proteome levels. We do all of these in order to systematically clarify the mechanism of quality formation of medicinal materials regulated by rhizosphere microecology changes of Angelica Sinensis.

根际微生态是药用植物-根际微生物-根系分泌物信息和物质交换的重要场所，是影响药材品质形成的重要因素，对根类药材影响尤其显著。文献及本课题组前期研究均证实，不同根际微生态条件下当归药材品质存在着明显差异。本研究拟从当归根际微生态的角度，提出当归植株-根际微生物-根系分泌物之间的相关作用对当归品质形成的研究，拟开展工作如下：（1）应用环境代谢组学和土壤宏基因组学研究技术，构建当归根系分泌物的代谢谱及根际微生物区系特征谱；（2）从转录组水平，分析当归次生代谢产物、根生长发育相关功能基因的表达差异；（3）基于PTRs分析模型，构建植物-土壤-微生物之间的效应关联模型，寻找品质相关特异功能菌；（4）进行多层次实验验证，阐述微生态调节当归品质的信号因子和功能基因代谢与调控路径。以期较为系统地回答当归根际微生态变化与对药材品质形成的调控机制。

根际微生态是药用植物-根际微生物-根系分泌物信息和物质交换的重要场所，是影响药材品质形成的重要因素，对根类药材影响尤其显著。文献及本课题组前期研究均证实，不同根际微生态条件下当归药材品质存在着明显差异。本研究从当归根际微生态的角度，提出当归植株-根际微生物-根系分泌物之间的相关作用对当归品质形成的研究，相关结论如下：.（1）对不同产区当归根际微生物区系进行分析发现，根际土壤中假单胞菌的高丰度对促进当归的分枝和根系生长起着重要的促进作用，不同来源当归种苗的根际微生物在群落组成和功能潜力上均有明显差异。不同的地理生态环境影响了当归次生代谢产物的积累。.（2）通过对来自甘肃、云南两个主要产区的土壤进行盆栽实验，证实了不同产区土著微生物对于当归的生长和发育都是必不可少。未灭菌组的根际土壤中特异细菌组合的高丰度有利于当归的生长和品质的增强。采用16S测序技术和代谢组学分析手段，挖掘不同种苗来源当归中关键原始微生物菌群的重要作用。当归根际土著微生物菌群，可以显著促进当归根的生长并提升其品质。.（3）通过宏基因组技术对当归根际土壤进行Circos分析，筛选出当归根际土壤细菌群落中的核心细菌，并成功分离出与当归品质相关的菌株（Bacillus-XG-2）。.当归组培苗-细菌共培养实验证实，添加菌液后显著增加了当归植株的株高和鲜重，表明Bacillus在当归生长过程中促进丁烯基苯酞积累，同时抑制了藁本内酯和阿魏酸的积累。进一步的分析结果揭示，Bacillus 可能通过下调桂皮酸合成途径中关键酶基因PAL、COMT的表达，从而负向调控阿魏酸的合成和积累。.通过上述工作，较为系统地回答当归根际微生态变化与对药材品质形成的调控机制，结果可对揭示当归品质形成及道地性成因具有理论指导意义和实际的应用价值。