Volatile organic compounds (VOCs) produced by bacteria have significant potential to control phytopathogens. In this study, the VOCs produced by endofungal bacteria Pseudomonas sp. Bi1, Bacillus sp. De3, Pantoea sp. Ma3 and Pseudomonas sp. De1 isolated from wild growing mushrooms were evaluated in vitro for their antagonistic activity against Pseudomonas tolaasii Pt18, the causal agent of mushroom brown blotch disease. The gas chromatography–mass spectrometry (GC–MS) analysis revealed that strains Pseudomonas sp. Bi1, Pseudomonas sp. De1, Bacillus sp. De3 and Pantoea sp. Ma3 produced eight, sixteen, nine, and twelve VOCs, respectively. All antagonistic endofungal bacteria produced VOCs which significantly reduced brown blotch symptoms on mushroom caps and inhibited the growth of P. tolaasii Pt18 at the varying levels. Scanning electron microscopy revealed severe morphological changes in cells of P. tolaasii Pt18 following exposure to the VOCs of Pseudomonas sp. Bi1 and De1. Furthermore, The VOCs produced by endofungal bacteria significantly reduced swarming, swimming, twitching, chemotaxis motility and biofilm formation by P. tolaasii Pt18 cells, which are essential contributors to pathogenicity. This is to first report about the inhibition effects of VOCs produced by antagonistic bacteria on virulence traits of P. tolaasii. Our findings provide new insights regarding the potential of antibacterial VOCs as a safe fumigant to control mushroom brown blotch disease.

细菌产生的挥发性有机化合物（VOC）具有控制植物病原体的巨大潜力。在这项研究中，由真菌内细菌假单胞菌（Pseudomonas sp。）产生的VOC 。Bi1，芽孢杆菌属。De3，Pantoea sp。Ma3和假单胞菌sp。从野生蘑菇中分离出的De1在体外评估了其对蘑菇褐斑病的病原体假单胞菌Pt18的拮抗活性。气相色谱-质谱（GC-MS）分析表明，菌株假单胞菌属（Pseudomonas sp。）。Bi1，假单胞菌属sp。De1，芽孢杆菌属。De3和Pantoeasp。Ma3分别产生了8、16、9和12个VOC。所有拮抗性真菌内细菌均产生VOC，可显着减少蘑菇帽上的棕色斑点症状，并在不同水平上抑制tolaasii Pt18的生长。扫描电子显微镜显示，暴露于假单胞菌属的挥发性有机化合物后，tolaasii Pt18细胞的形态发生了严重变化。Bi1和De1 。此外，由真菌内细菌产生的挥发性有机化合物显着减少了斑节对虾的群聚，游泳，抽搐，趋化运动和生物膜形成。Pt18细胞是致病性的重要因素。这是首次报道拮抗细菌产生的挥发性有机化合物对Tolaasii毒力特性的抑制作用。我们的发现提供了有关抗菌VOC作为控制蘑菇褐斑病的安全熏蒸剂潜力的新见解。