| Title | An endophytic Coniochaeta velutina producing broad spectrum antimycotics |
|---|---|
| Author | Jie Xie1, Gary A. Strobel2*, Tao Feng3, Huishuang Ren1, Morgan T. Mends2, Zeyang Zhou1, and Brad Geary4 |
| Address | 1State Key Laboratory of Silkworm Genome Biology, College of Biotechnology, Southwest University, Chongqing 400715, P. R. China, 2Department of Plant Sciences, Montana State University, Bozeman, Montana, 59717, USA, 3State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, P. R. China, 4Department of Plant and Wildlife Sciences, Brigham Young University, Provo, UT 84602, USA |
| Bibliography | Journal of Microbiology, 53(6),390-397, 2015, |
| DOI | 10.1007/s12275-015-5105-5 |
| Key Words | antimycotics, endophyte, Coniochaeta velutina, bioassays, SEM |
| Abstract | An endophyte (PC27-5) was isolated from stem tissue of Western hemlock (Tsuga heterophylla) in a Pacific Northwest temperate rainforest. Phylogenetic analyses, based on ITS- 5.8S rDNA and 18S rDNA sequence data, combined with cultural and morphological analysis showed that endophyte PC27-5 exhibited all characteristics of a fungus identical to Coniochaeta velutina. Furthermore, wide spectrum antimycotics were produced by this endophyte that were active against such plant pathogens as Sclerotinia sclerotiorum, Pythium ultimum, and Verticillium dahliae and lethal to Phythophthora cinnamomi, Pythium ultimum, and Phytophthora palmivora in plate tests. The bioactive components were purified through organic solvent extraction, followed by silica column chromatography, and finally preparative HPLC. The minimum inhibitory concentration of the active fraction to Pythium ultimum, which was gained from preparative HPLC, was 11 ?/ml. UPLC-HRMS analysis showed there were two similar components in the antimycotic fraction. Their molecular formulae were established as C30H22O11 (compound I) and C30H22O10 (compound II) respectively, and preliminary spectral results indicate that they are anthroquinone glycosides. Other non ?biologically active compounds were identified in culture fluids of this fungus by spectral means as emodin and chrysophanol - anthroquinone derivatives. This is the first report that Coniochaeta velutina as an endophyte produces bioactive antifungal components. |