烟草内生真菌多样性及其细胞毒活性初步研究

The Biodiversity of Endophytic Fungi in Nicotiana Tabacum and Their Cytotoxicity

为研究烟草内生真菌的生物多样性,揭示其在烟草中的分布规律及种群结构,对烟草栽培种的内生真菌进行了系统的分离和鉴定,并对其发酵粗提物进行了初步的细胞毒活性筛选。结果发现,采用组织分离法从健康烟株的根、茎、叶中共分离纯化到62株内生真菌,形态学和分子生物学鉴定为4目7科9属。发现叶部内生真菌的分离率最高,其次为茎,根部最少。采用CCK-8法对内生真菌的体外细胞毒活性进行筛选,发现多数菌株对人肾癌Caki-1细胞和人肝癌Hep G2细胞均具有不同程度的抑制活性,菌株TE-6L的PDB发酵液及大米发酵物对Caki-1细胞48 h内的IC50分别为13.28和0.36μg/m L。结合形态学特征和分子生物学鉴定TE-6L菌株为Fusarium sambucinum。研究表明,烟草中蕴含丰富的具有细胞毒活性的内生真菌资源,为寻找细胞毒活性物质新来源、开发新型抗肿瘤药物提供了新的途径。

To investigate the biodiversity,distribution,and the microbial community structure of the endophytic fungi in Nicotiana tabacum,the endophytic fungi in different cultispecies were systematically isolated and identified.The preliminary screening of the cytotoxic activities was also performed.As a result,a total of62strains of the endophytic fungi were isolated and purified from the healthy tissues(roots,stems,and leaves)of tobacco using the tissue isolation method.The isolated strains were identified to belong to4orders,7families,and9genera based on their morphological and molecular characteristics.More species and strains were isolated from the leaves,followed by the stems,and those in the roots were the least.The cytotoxicity of the crude extracts was determined by CCK-8assay.The results indicated that most of the strains were found to have some inhibitory activities on Caki-1and HepG2cell lines.The IC50s of the strain TE-6L to Caki-1at24h and48h were13.28and0.36μg/mL,respectively.Combined with morphological characteristics and molecular analysis,this strain was identified as Fusarium sambucinum.The results from this study indicated that the tobacco possess abundant endophytic fungi,which provides a new path for searching for novel antitumor resources.