Chen Yi-Huang, Zhang Jia-Xing, Min Yan, Liu Yang, Wang Jian-Ming, Bai Lin-Quan, Luo Xiao-Xia
State Key Laboratory Incubation Base for Conservation and Utilization of Bio-Resource in Tarim Basin, Alar, Xinjiang Uygur Autonomous Region, 843300, China.
School of Life Science and Technology, Tarim University, Alar, Xinjiang Uygur Autonomous Region, 843300, China.
BMC Microbiol. 2024 Dec 31;24(1):550. doi: 10.1186/s12866-024-03609-6.
Pear black spot is caused by Alternaria tenuissima. It is one of the diseases of concern limiting pear production worldwide. Existing cultivation methods and fungicides are not sufficient to control early blight. Therefore, the aim of this study was to isolate and characterize two strains of Streptomyces and evaluate their potential for biological control of crop diseases caused by Alternaria tenuissima while promoting plant growth. It enriches the resources of biocontrol strains.
In this study, the genetic background of the strain was elucidated through 16S rRNA gene analysis and multiphase taxonomic identification methods. The metabolic potential of the strain was assessed using a variety of approaches, including antiSMASH, COG, and KEGG databases, RGI tools, as well as the scanning of CAZY and plant-promoting genes. The biocontrol potential of the strain was further substantiated through a combination of plate experiments, gene cluster biopathway resolution and mass spectrometry validation of metabolites. Finally, the biocontrol efficacy of the strain was confirmed through fruit control experiments.
The study identified the potential new species status of the strains. Strain TRM 76130 exhibited a gene size of 5.94 Mbp and a G + C content of 73.65%, while strain TRM 76172 had a gene size of 8.30 Mbp and a G + C content of 71.38%. Both strains contained genes related to amino acid transport and metabolism, along with several CAZY genes and 19 plant growth factors. The resistance genes of strain TRM 76172 were classified as macrolides, and genomic prediction revealed the biosynthetic pathway of the active compound Candidin. Mass spectrometry analysis indicated that strains TRM 76172 and TRM 76130 contained the active compounds amphotericin A and daptomycin, respectively. The pear assays demonstrated that both strains of Streptomyces were capable of reducing the symptoms of pear black spot.
The present study concludes that strains TRM76172 and TRM76130 possess significant potential to control Alternaria tenuissima and promote plant growth, thereby enriching the biocontrol fungal library.
梨黑斑病由细极链格孢引起。它是限制全球梨产量的重要病害之一。现有的栽培方法和杀菌剂不足以控制早疫病。因此，本研究的目的是分离和鉴定两株链霉菌菌株，评估它们对由细极链格孢引起的作物病害的生物防治潜力，同时促进植物生长。这丰富了生物防治菌株的资源。
在本研究中，通过16S rRNA基因分析和多相分类鉴定方法阐明了菌株的遗传背景。使用多种方法评估了菌株的代谢潜力，包括antiSMASH、COG和KEGG数据库、RGI工具，以及对CAZY和植物促生基因的扫描。通过平板实验、基因簇生物途径解析和代谢产物的质谱验证相结合，进一步证实了菌株的生物防治潜力。最后，通过果实防治实验证实了菌株的生物防治效果。
该研究确定了这些菌株潜在的新物种地位。菌株TRM 76130的基因大小为5.94 Mbp，G + C含量为73.65%，而菌株TRM 76172的基因大小为8.30 Mbp，G + C含量为71.38%。两株菌株都含有与氨基酸转运和代谢相关的基因，以及几个CAZY基因和19种植物生长因子。菌株TRM 76172的抗性基因被归类为大环内酯类，基因组预测揭示了活性化合物杀假丝菌素的生物合成途径。质谱分析表明，菌株TRM 76172和TRM 76130分别含有活性化合物两性霉素A和达托霉素。梨试验表明，两株链霉菌菌株都能够减轻梨黑斑病的症状。
本研究得出结论，菌株TRM76172和TRM76130在控制细极链格孢和促进植物生长方面具有显著潜力，从而丰富了生物防治真菌库。
