Discovery of murayaquinone from an endophytic bacterium Streptomyces sp. AN140557 as a potent inhibitor of the pine wood nematode, Bursaphelenchus xylophilus.

BACKGROUND: Bursaphelenchus xylophilus, the pine wood nematode (PWN), is responsible for causing pine wilt disease (PWD), leading to significant ecological and economic damage in pine forests. Endophytes are well-known producers of bioactive secondary metabolites, offering potential for environmentally friendly control agents. This study focused on identifying and evaluating nematicidal compounds from pine tree endophytes active against PWN.

RESULTS: A total of 30 endophytes isolated from Korean pine trees were screened for their nematicidal activity and identified as novel nematicidal agents against PWN. Among them, Streptomyces sp. AN140557 showed the highest nematicidal activity. The active compound, murayaquinone, was isolated by nematicidal activity-guided fractionation, and it showed significant dose-dependent nematicidal activity and egg-hatching inhibition against PWN at 3.12, 6.25, 12.5, and 25 μM, respectively. Exposure to 25 μM murayaquinone led to 100% mortality of PWN. Additionally, murayaquinone strongly suppressed egg hatching. In addition, the assessment of the activity against the other four plant parasitic nematodes (Meloidogyne incognita, Ditylenchus destructor, Aphelenchoides subtenuis, and Heterodera trifolii) showed that it has a broad nematicidal spectrum. The greenhouse experiments suggested that the murayaquinone efficiently inhibited the development of PWD in 5-year-old Pinus thunbergii plants.

CONCLUSION: Our results highlight the nematicidal potential of the murayaquinone derived from Streptomyces sp. AN140557. This is the first report of murayaquinone exhibiting biocontrol potential against PWN, suggesting its possibility as a PWD control agent. © 2025 The Author(s). Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.