title: Production of antifungal and antiinsectan metabolites by the Picea endophyte Diaporthe maritima sp. nov.
abstract: The genus Diaporthe comprises close to 800 species, with around 2000 names attributed to it and its asexual morphs previously recognized in Phomopsis. Diaporthe species are common plant associates, including saprotrophs, pathogens, and endophytes affiliated with a diverse range of hosts worldwide. In this study, an unknown Diaporthe sp. was frequently isolated as an endophyte from healthy Picea mariana and Picea rubens needles in the Acadian forest of Eastern Canada. Morphological observations and the application of the genealogical concordance phylogenetic species recognition concept using four unlinked loci (internal transcribed spacer (ITS), DNA-lyase (Apn2), translation elongation factor 1-α (EF1-α), and beta-tubulin (TUB)) support the distinctiveness of this species, described here as Diaporthe maritima. Crude liquid culture extracts from this new species showed potent antifungal activity towards the biotrophic pathogen Microbotryum violaceum in a screening assay necessitating an investigation of its natural products. Three dihydropyrones, phomopsolides A (1), B (2), and C (3), and a stable alpha-pyrone (4), were characterized by mass spectrometry and spectroscopic techniques. All isolated metabolites individually demonstrated in vitro antifungal and antibiotic activity towards Bacillus subtilis. The Acadian forest has proven to be a rich source of biodiversity that has the potential to deliver environmentally sustainable pest management tools.
authors.affiliation: Agriculture and Agri-Food Canada, Ottawa Research and Development Centre, 960 Carling Avenue, Ottawa, ON K1A 0C6, Canada; Department of Chemistry, Carleton University, 1125 Colonel By Drive, Ottawa, ON K1S 5B6, Canada. Electronic address: joey.tanney@agr.gc.ca.
authors.forename: Joey B
authors.initials: JB
authors.lastname: Tanney
authors.affiliation: Department of Chemistry, Carleton University, 1125 Colonel By Drive, Ottawa, ON K1S 5B6, Canada.
authors.forename: David R
authors.initials: DR
authors.lastname: McMullin
authors.affiliation: Department of Chemistry, Carleton University, 1125 Colonel By Drive, Ottawa, ON K1S 5B6, Canada.
authors.forename: Blake D
authors.initials: BD
authors.lastname: Green
authors.affiliation: Department of Chemistry, Carleton University, 1125 Colonel By Drive, Ottawa, ON K1S 5B6, Canada.
authors.forename: J David
authors.initials: JD
authors.lastname: Miller
authors.affiliation: Agriculture and Agri-Food Canada, Ottawa Research and Development Centre, 960 Carling Avenue, Ottawa, ON K1A 0C6, Canada.
authors.forename: Keith A
authors.initials: KA
authors.lastname: Seifert
mesh_terms: D000818:Animals; D000935:Antifungal Agents / Q000737:chemistry / Q000378:metabolism* / Q000494:pharmacology; D001203:Ascomycota / Q000737:chemistry* / Q000145:classification / Q000302:isolation & purification* / Q000378:metabolism; D060026:Endophytes / Q000737:chemistry* / Q000145:classification / Q000302:isolation & purification* / Q000378:metabolism; D007313:Insecta / Q000187:drug effects; D007306:Insecticides / Q000737:chemistry / Q000378:metabolism* / Q000494:pharmacology; D015394:Molecular Structure; D010802:Phylogeny; D028222:Picea / Q000382:microbiology*
chemical_list: D000935:Antifungal Agents; D007306:Insecticides
keywords: Diaporthales; GCPSR; Natural products; Phomopsis; Phomopsolides; Phylogenetic species