Yang Fuzhen, Zhang Ruyang, Wu Xianyu, Xu Tianjun, Ahmad Shahbaz, Zhang Xiaoxia, Zhao Jiuran, Liu Yang
School of Chemistry and Biological Engineering, University of Science and Technology Beijing, Beijing, 100083, China.
Maize Research Center, Beijing Academy of Agriculture and Forestry Sciences, Beijing, 100097, China.
Microb Pathog. 2020 Feb 24;142:104074. doi: 10.1016/j.micpath.2020.104074.
Plant endophytes are microbes that colonize plant internal tissues and are ubiquitously associated with plants. In this study, seven endophytic bacterial strains, 665L2, 725L2, 725R2, 92R2, 728R3, 728R4 and 2416T3, were isolated from seeds of five healthy maize varieties (Zea mays L.) and all identified as Bacillus velezensis by polyphasic taxonomy based on 16S rRNA and gyrA gene phylogenetic analysis. In addition, according to the genotyping results from random amplified polymorphic DNA (RAPD), 665L2, 725L2, 725R2 and 92R2 belonged to the same strain, while 728R3 and 2416T3 belonged to another strain. Pathogenic fungal strains 4, 5 and 6 were isolated from three diseased maize varieties (Zea mays L.), and they were identified as Talaromyces funiculosus, Penicillium oxalicum and Fusarium verticillioides, respectively, by polyphasic taxonomy based on morphological identification, ITS rDNA and bio-control gene phylogenetic analyses. Seven endophytic bacterial Bacillus velezensis strains had favourable antagonistic activity, and antagonistic testing was carried out against the three pathogenic strains, Talaromyces funiculosus 4, Penicillium oxalicum 5 and Fusarium verticillioides 6. Biological control lipopeptide antibiotic genes (bioA, bmyB, ituC, fenD, srfAA, srfAB, yngG and yndJ) were amplified using specific primers, and they were found in the seven endophytic bacterial Bacillus velezensis strains. This study provides a scientific basis for future research on the use of resistant endophytic bacterial resources to enhance crop production.
植物内生菌是定殖于植物内部组织且普遍与植物相关联的微生物。在本研究中，从五个健康玉米品种（玉米）的种子中分离出七株内生细菌菌株，分别为665L2、725L2、725R2、92R2、728R3、728R4和2416T3，通过基于16S rRNA和gyrA基因系统发育分析的多相分类法，均鉴定为贝莱斯芽孢杆菌。此外，根据随机扩增多态性DNA（RAPD）的基因分型结果，665L2、725L2、725R2和92R2属于同一菌株，而728R3和2416T3属于另一菌株。从三个患病玉米品种（玉米）中分离出致病真菌菌株4、5和6，通过基于形态鉴定、ITS rDNA和生物防治基因系统发育分析的多相分类法，分别鉴定为绳状青霉、草酸青霉和轮枝镰孢菌。七株内生贝莱斯芽孢杆菌菌株具有良好的拮抗活性，并对三种致病菌株绳状青霉4、草酸青霉5和轮枝镰孢菌6进行了拮抗试验。使用特异性引物扩增生物防治脂肽抗生素基因（bioA、bmyB、ituC、fenD、srfAA、srfAB、yngG和yndJ），发现它们存在于七株内生贝莱斯芽孢杆菌菌株中。本研究为未来利用抗性内生细菌资源提高作物产量的研究提供了科学依据。
