植物内生菌产生的聚酮类和非核糖体肽类次生代谢产物具有多种生物活性，基于聚酮合成酶（PKS）和非核糖体多肽合成酶（NRPS）功能基因定向筛选，预测内生菌产生新的次生代谢产物的能力，成为发现新颖天然活性物质的重要策略之一。药用牡丹根皮具抗菌、消炎和抗肿瘤等多种生物活性，前期研究表明牡丹根皮中存在大量的内生细菌，部分菌株的非核糖体肽类化合物对牡丹病原真菌具有较好的抑制作用。在前期工作基础上，继续对药用牡丹根皮中的内生细菌进行分离，采用功能基因定向筛选技术探讨内生菌株合成新型聚酮类和非核糖体肽类化合物的能力；根据功能基因转录组表达水平优化目标菌株发酵条件；利用现代色谱和波谱技术，分离、纯化并鉴定活性代谢产物的结构；生物活性追踪其抗菌抗肿瘤活性。研究结果将为抗菌抗肿瘤药物提供产生菌及其结构新颖的候选化合物，并为探讨微生物功能基因与微生物次生代谢产物间的相关性研究奠定基础。

Polyketides（PKs) and nonribosomal peptides (NRPs) secondary metabolites with diverse bioactivities are produced by plant endophytes. The polyketide synthases (PKSs) and nonribosomal peptide synthetases (NRPSs) gene-based molecular approach can be applied to efficient screening of endophyte-derived novel bioactive natural products. The root of medicinal tree peony contains many kinds of pharmacological compounds, such as anti-microbial, anti-inflammatory and anti-tumor activities compound. Preliminary results indicated that many endophytic bacteria existed in tree peony root, and the nonribosomal peptide compounds produced by some bacteria exhibited inhibitory activity on mycelium growth of peony pathogenic fungi. In this study, endophytic bacteria will be isolated further from medicinal tree peony root. The novel bioactive peptide and polyketide-producing capability of endophytic bacteria will be assessed based on approach of polymerase chain reaction (PCR) screening of function gene associated with the PKS and NRPS. The transcriptional expression levels of PKS and NRPS gene will be studied to determine the optimal fermentation conditions of the aimed strains. The bioactive compounds will be isolated and purified from the active strains by thin layer chromatography (TLC) and high performance liquid chromatography (HPLC) methods. The structures of these compounds will be elucidated by means of spectroscopic methods, and the compounds will be evaluated for their antimicrobial and antitumor activities. The microorganism resources and new natural active compounds with particular function and potential application will be obtained through this research. This study will lay the foundation for the correlation between microbial functional gene and microbial secondary metabolites.