蛇足石杉内生真菌多样性及产AChEI真菌在宿主中分布规律

Acetylcholinesterase inhibitors (AChEI) are promising and effective medications for Alzheimer's disease (AD) in clinical setting at present, which have prompted researchers from various countries to pay high attention to bioprospecting novel AChEI and broaden its new approach. Endophytic fungi was a large microbial population with abundance in biodiversity, it has been found to produce similar chemical compounds to those produced by its host and also has been recognized as a repository of novel compounds of immense value in medicine. Previous studies we found that the distribution of these AChEI-producing endophytic fungi in Huperzia serrata may be some correlation to the content of huperzine A (HupA) in host tissues. In this study, we devote oneself to base on culture-dependent and culture-independent methods to systematicly investigate the diversity of endophytic fungi in H. serrata, also to screen the endophytic AChEI-producing fungi residing in the tissues of H. serrata. Then we try to probing into the correlation between content of HupA during different seasons, tissues in host and the distribution of AChEI-producing endophytic fungi in H. serrata. Base on the results of this study we can not only systematicly investigate the diversity, population dynamics of endophytic fungi in H. serrata, construct endophytic fungi natural resources pool, exposit the correlation between content of HupA in host and the distribution of AChEI-producing endophytic fungi in H. serrata, but also can lay the foundation for high throughput screening AChEI-producing endophytic fungi and broaden AChEI new approach.

乙酰胆碱酯酶抑制剂（AChEI）是目前临床上治疗阿尔茨海默氏病（AD）最具前景的药物之一，勘探新型AChEI并拓宽其药源途径一直是该领域研究的热点。植物内生真菌多样性极为丰富并可产生与宿主相同或相似的药用活性化合物，是当前生物勘探新型天然药用活性化合物的重要资源。课题组的前期研究发现产AChEI蛇足石杉内生真菌的分布极有可能与宿主石杉碱甲（HupA）含量相关。本项目采用培养法和免培养法相结合，系统开展药用蕨类植物蛇足石杉内生真菌菌群多样性研究，并筛选产AChEI真菌。在此基础上，探讨不同季节植株不同组织中HupA含量与产AChEI内生真菌分布的相关性。本研究不但能系统阐明蛇足石杉内生真菌菌群多样性及结构动态规律，建立产AChEI内生真菌资源库，揭示植株HupA含量与产AChEI内生真菌分布的相关性，而且能为高通量筛选高产AChEI内生真菌、拓宽当前AChEI的来源途径奠定基础。

植物内生真菌多样性极为丰富并可产生与宿主相同或相似的药用活性化合物，是当前生物勘探新型天然药用活性化合物的重要资源。乙酰胆碱酯酶抑制剂（AChEI）是目前临床上治疗阿尔茨海默氏病（AD）最具前景的药物之一，勘探新型AChEI并拓宽其药源途径一直是该领域研究的热点。本项目采用培养法和免培养法相结合，系统开展药用蕨类植物蛇足石杉内生真菌菌群多样性研究，并筛选产AChEI真菌。同时，测定植株不同组织部位中石杉碱甲（HupA）的含量，在此基础上，探讨蛇足石杉植株不同组织中HupA的含量高低与产AChEI内生真菌分布的相关性，试图揭示产AChEI内生真菌在蛇足石杉中分布的规律。结果表明，蛇足石杉中蕴藏着种类繁多，种属多样的内生真菌种群。其中可培养内生真菌分属于56个属，还有32个分类单元未能鉴定到种属，Arthrobotrys sp.、Botryosphaeria sp.等31个属为首次从蛇足石杉中分离报道的内生真菌，而采用MiSeq高通量测序分析共计检测到264个属内生真菌。茎和叶中内生真菌的种属组成较为相似，分离获得的内生真菌的数量也较根中的多。蛇足石杉植株的地上部分（茎和叶）中的HupA含量高于地下部分（根）的含量，植株中HupA含量呈现时空动态变化，且在12月达到最高，为325.9 μg·g-1。分离筛选获得300余株产AChEI的内生真菌，且其在植株不同组织中的分离率高低与组织中HupA含量的高低没有相关性。本研究不仅阐明了蛇足石杉内生真菌菌群多样性和菌株分布特性，建立了产AChEI内生真菌资源库，掌握了蛇足石杉植株中HupA含量的动态变化规律，而且能为高通量筛选高产AChEI内生真菌、拓宽当前AChEI的来源途径奠定基础。