植物内生菌G-1菌株的鉴定及其拮抗物质的初步研究  

Preliminary study on identification of plant endophytic bacteria G-1 and its antagonistic function

作　　者：郭洁心 马超 朱洪磊 张宝俊[1] Guo Jiexin;Ma Chao;Zhu Honglei;Zhang Baojun(College of Agriculture,Shanxi Agricultural University,Taigu 030801,China)

机构地区：[1]山西农业大学农学院

出　　处：《山西农业大学学报（自然科学版）》2020年第1期59-65,共7页Journal of Shanxi Agricultural University(Natural Science Edition)

基　　金：山西省科技基础条件平台项目(201605D121024)

摘　　要：[目的]G-1菌株为1株对多种病原真菌具有拮抗活性的植物内生细菌,本研究旨在明确G-1菌株的分类地位及其抗菌物质的主要类型。[方法]首先,采用平板对峙法分析其抑菌谱,然后通过形态学观测与分子检测相结合界定G-1菌株的分类地位,再进行理化性质测定的同时通过脂肽类抗生素编码基因簇分析,进一步研究该菌株代谢物中抗菌物质的主要类型。[结果]G-1菌株具有较强的抑菌活性(抑菌率69.1%~83.14%),是较广的抗菌谱(对9种病原菌均有抑制作用)。在形态分析的基础上,综合16SrDNA、gyr A和gyr B基因数据集分析,发现G-1菌株与甲基营养型芽孢杆菌(Bacillus methylotrophicus)的相似度最高,达91%。菌株的理化特性分析发现,G-1菌株抗菌粗提物在热稳定性、酸碱稳定性及抗紫外辐射方面都有较好的表现,如121℃处理30 min后对番茄灰霉病菌的抑菌率为81.76%,与对照相比仍保持其86.7%的活性。特异引物扩增分析发现,G-1菌株拥有分泌itu A、fen A、srf C的能力,表明G-1菌株可能是通过分泌抗菌脂肽类物质达到抑菌的作用。[结论]菌株G-1为1株具有开发潜力的拮抗菌株,研究结果可为后期生防菌制剂的研发奠定基础和数据支撑。[Objective]A new plant endophytic bacteria strain G-1 isolated from clover tree stems is of antifungal activity against various pathogenic fungi.This study aimed to clarify the taxonomic status of G-1 and identify the antifungal substances produced by G-1.[Methods]The fungi static spectrum of G-1 was analyzed using dual culture assay,and the taxonomic status of G-1 was defined by the combination of morphological observation and molecular detection analysis.Coupled with physical and chemical properties determination,the major antifungal substances in the metabolites of G-1 were investigated by the analysis of lipopeptide antibiotic coding gene cluster.[Results]The results showed that strain G-1 possessed high antifungal activity and wide antifungal spectrum,and the inhibitory activities against nine pathogenic fungi were ranged between 69.1%and 83.14%.Based on the morphological analysis,16SrDNA,gyrA and gyrB gene data set analysis was conducted and the results revealed a high similarity of G-1(up to 91%)to Bacillus methylotrophicus.Analysis of the physical and chemical properties of the strain G-1 indicated that the crude extract of strain G-1 demonstrated antifungal activity,good thermal stability,acid and basic stability and anti-ultraviolet radiation activity of metabolites produced by G-1.For example,G-1 crude extract maintained the inhibitory activity against Botrytis cinereaup to 81.7%after heat treatment at 121℃for 30 min,which was at 86.7%of non-heat treatment control group.Primer specific amplification analysis results indicated that the strain G-1 could secrete itu A,fen A,and srf C genes,which indicated that strain G-1 may have inhibitory effect by producing antimicrobial lipopeptide substances.[Conclusion]Strain G-1 is of potential to be developed as an newly antagonistic agent,and our study provided a scientific support for the further development of this strain.

关 键 词：拮抗菌 甲基营养型芽孢杆菌 抗菌脂肽 理化性质 

分 类 号：S476[农业科学—农业昆虫与害虫防治]