Zheng Yanfen, Han Xiaobin, Zhao Donglin, Wei Keke, Yuan Yuan, Li Yiqiang, Liu Minghong, Zhang Cheng-Sheng
Pest Integrated Management Key Laboratory of China Tobacco, Tobacco Research Institute of Chinese Academy of Agricultural Sciences, Qingdao, China.
Biological Organic Fertilizer Engineering Technology Center of China Tobacco, Zunyi Branch of Guizhou Tobacco Company, Zunyi, China.
Front Plant Sci. 2021 Mar 19;12:655673. doi: 10.3389/fpls.2021.655673. eCollection 2021.
Recent studies have observed differing microbiomes between disease-suppressive and disease-conducive soils. However, it remains unclear whether the microbial keystone taxa in suppressive soil are critical for the suppression of diseases. Bacterial wilt is a common soil-borne disease caused by that affects tobacco plants. In this study, two contrasting tobacco fields with bacterial wilt disease incidences of 0% (disease suppressive) and 100% (disease conducive) were observed. Through amplicon sequencing, as expected, a high abundance of was found in the disease-conducive soil, while large amounts of potential beneficial bacteria were found in the disease-suppressive soil. In the fungal community, an abundance of the genus, which contains species that cause wilt, showed a positive correlation ( < 0.001) with the abundance of . Network analysis revealed that the healthy plants had more complex bacterial networks than the diseased plants. A total of 9 and 13 bacterial keystone taxa were identified from the disease-suppressive soil and healthy root, respectively. Accumulated abundance of these bacterial keystones showed a negative correlation ( < 0.001) with the abundance of . To complement network analysis, culturable strains were isolated, and three species belonging to showed high 16S rRNA gene similarity (98.4-100%) with keystone taxa. These strains displayed strong inhibition on pathogens and reduced the incidence of bacterial wilt disease in greenhouse condition. This study highlighted the importance of keystone species in the protection of crops against pathogen infection and proposed an approach to obtain beneficial bacteria through identifying keystone species, avoiding large-scale bacterial isolation and cultivation.
最近的研究观察到了抑病土壤和感病土壤之间存在不同的微生物群落。然而，尚不清楚抑病土壤中的微生物关键类群对病害抑制是否至关重要。青枯病是一种由[具体病原体未给出]引起的常见土传病害，会影响烟草植株。在本研究中，观察了两个对比鲜明的烟草田，青枯病发病率分别为0%（抑病）和100%（感病）。通过扩增子测序，正如预期的那样，在感病土壤中发现了高丰度的[具体微生物未给出]，而在抑病土壤中发现了大量潜在的有益细菌。在真菌群落中，大量含有导致青枯病的物种的[具体真菌属未给出]属与[具体微生物未给出]的丰度呈正相关（<0.001）。网络分析表明，健康植株的细菌网络比患病植株更复杂。分别从抑病土壤和健康根系中鉴定出9个和13个细菌关键类群。这些细菌关键类群的累积丰度与[具体微生物未给出]的丰度呈负相关（<0.001）。为补充网络分析，分离了可培养菌株，属于[具体属未给出]的三个物种与关键类群的16S rRNA基因相似度很高（98.4 - 100%）。这些菌株对病原体表现出强烈的抑制作用，并降低了温室条件下青枯病的发病率。本研究强调了关键物种在保护作物免受病原体感染方面的重要性，并提出了一种通过鉴定关键物种来获取有益细菌的方法，避免了大规模的细菌分离和培养。
