Antifungal activity of xenocoumacin 1 from Xenorhabdus nematophilus var. pekingensis against Phytophthora infestans

• DOI: 10.1007/s11274-010-0485-5
• Publication Date: 2010-06-24T05:14:23Z
• Authors: Xiufen Yang; Dewen Qiu; Huaiwen Yang; Zheng Liu; Hongmei Zeng; Jingjing Yuan
• Keywords: Phytophthora infestans; EC50

Potato late blight disease, which is caused by the fungus Phytophthora infestans, results in considerable loss of potato crop yield worldwide. Developing new bio-agents to control this disease is desirable. Xenocoumacin 1 (Xcn1) is an antibacterial substance from the entomopathogenic nematode symbiotic bacterium, Xenorhabdus nematophila var. pekingensis. In this study, we evaluated the antifungal activity of Xcn1, along with its potential activity against Phytophthora infestans, in vitro and in vivo. The results showed that Xcn1 exhibits strong antifungal activity against five species of Phytophthora, with EC50 values ranging from 0.25 to 4.17 μg/mL. Xcn1 not only inhibited mycelial growth of P. infestans, reaching 100% inhibition at 1.5 μg/mL of Xcn1, but also suppressed sporangia production. Xcn1 also showed potent in vivo activity against P. infestans, with 92.63% and 80.27% in detached plants and potted plants, respectively, in comparison with the control. Therefore, Xcn1 has antibiotic activities against P. infestans both in vitro and in vivo.