The Sanya Institute of the Nanjing Agricultural University, Jiangsu Provincial Key Lab for Solid Organic Waste Utilization, Jiangsu Collaborative Innovation Center of Solid Organic Wastes, Educational Ministry Engineering Center of Resource-Saving Fertilizers, Nanjing Agricultural University, Nanjing, Jiangsu, 210095, China.
Ecology and Biodiversity Group, Department of Biology, Institute of Environmental Biology, Utrecht University, Padualaan 8, 3584 CH, Utrecht, The Netherlands.
Microbiome. 2024 Oct 28;12(1):221. doi: 10.1186/s40168-024-01947-1.
Fertilization practices control bacterial wilt-causing Ralstonia solanacearum by shaping the soil microbiome. This microbiome is the start of food webs, in which nematodes act as major microbiome predators. However, the multitrophic links between nematodes and the performance of R. solanacearum and plant health, and how these links are affected by fertilization practices, remain unknown.
Here, we performed a field experiment under no-, chemical-, and bio-organic-fertilization regimes to investigate the potential role of nematodes in suppressing tomato bacterial wilt. We found that bio-organic fertilizers changed nematode community composition and increased abundances of bacterivorous nematodes (e.g., Protorhabditis spp.). We also observed that pathogen-antagonistic bacteria, such as Bacillus spp., positively correlated with abundances of bacterivorous nematodes. In subsequent laboratory and greenhouse experiments, we demonstrated that bacterivorous nematodes preferentially preyed on non-pathogen-antagonistic bacteria over Bacillus. These changes increased the performance of pathogen-antagonistic bacteria that subsequently suppressed R. solanacearum.
Overall, bacterivorous nematodes can reduce the abundance of plant pathogens, which might provide a novel protection strategy to promote plant health. Video Abstract.
受精实践通过塑造土壤微生物组来控制引起细菌性枯萎病的罗尔斯顿氏菌。这个微生物组是食物网的起点，其中线虫作为主要的微生物组捕食者。然而，线虫与罗尔斯顿氏菌和植物健康的多营养联系，以及这些联系如何受到受精实践的影响，仍然未知。
在这里，我们在无、化学和生物有机施肥制度下进行了田间实验，以研究线虫在抑制番茄细菌性枯萎病方面的潜在作用。我们发现，生物有机肥料改变了线虫群落组成，并增加了食细菌线虫（例如，Protorhabditis 属）的丰度。我们还观察到，病原菌拮抗细菌，如芽孢杆菌，与食细菌线虫的丰度呈正相关。在随后的实验室和温室实验中，我们证明了食细菌线虫优先捕食非病原菌拮抗细菌而不是芽孢杆菌。这些变化增加了病原菌拮抗细菌的性能，随后抑制了罗尔斯顿氏菌。
总的来说，食细菌线虫可以减少植物病原体的丰度，这可能为促进植物健康提供一种新的保护策略。视频摘要。
