Antifungal Activities of Volatile Secondary Metabolites of Four Diaporthe Strains Isolated from Catharanthus roseus (PDF) (503.5Kb)
Yan, Dong-Hui
Luo, Tushou
Dou, Guiming
Four endophytic fungi were isolated from the medicinal plant, Catharanthus roseus, and were identified as Diaporthe spp. with partial translation elongation factor 1-alpha (TEF1), beta-tubulin (TUB), histone H3 (HIS), calmodulin (CAL) genes, and rDNA internal transcribed spacer (ITS) region (TEF1-TUB-HIS--CAL-ITS) multigene phylogeny suggested for species delimitation in the Diaporthe genus. Each fungus produces a unique mixture of volatile organic compounds (VOCs) with an abundant mixture of terpenoids analyzed by headspace solid-phase microextraction (SPME) fiber-GC/MS. These tentatively-detected terpenes included Î±-muurolene, Î²-phellandrene, Î³-terpinene, and Î±-thujene, as well as other minor terpenoids, including caryophyllene, patchoulene, cedrene, 2-carene, and thujone. The volatile metabolites of each isolate showed antifungal properties against a wide range of plant pathogenic test fungi and oomycetes, including Alternaria alternata, Botrytis cinerea, Colletotrichum gloeosporioides, Fusarium graminearum, and Phytophthora cinnamomi. The growth inhibition of the pathogens varied between 10% and 60% within 72 h of exposure. To our knowledge, the endophytic Diaporthe-like strains are first reported from Catharanthus roseus. VOCs produced by each strain of the endophytic Diaporthe fungi were unique components with dominant monoterpenes comparing to known Diaporthe fungal VOCs. A discussion is presented on the inhibitive bioactivities of secondary metabolites among endophytic Diaporthe fungi and this medicinal plant.
Yan, Dong-Hui, Xiaoyu Song, Hongchang Li, Tushou Luo, Guiming Dou, and Gary Strobel. "Antifungal Activities of Volatile Secondary Metabolites of Four Diaporthe Strains Isolated from Catharanthus roseus." Journal of Fungi 4, no. 2 (May 2018). DOI:10.3390/jof4020065.