|CHO, GYEONGJUN - Gyeongsang National University
|KIM, JUNHEON - National Institute For Agricultural Science & Technology
|PARK, CHUNG GYOO - Gyeongsang National University
|NISLOW, COREY - University Of British Columbia
|KWAK, YOUN-SIG - Gyeongsang National University
Submitted to: The Open Biology Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/28/2017
Publication Date: 5/1/2018
Citation: Cho, G., Kim, J., Park, C., Nislow, C., Kwak, Y., Weller, D.M. 2018. Caryolan-1-ol, an antifungal volatile produced by Streptomyces spp., inhibits the endomembrane system of fungi. The Open Biology Journal. 7:170075.
Interpretive Summary: Streptomyces spp. are soil dwelling bacteria that are well-known for their ability to produce a very wide range of antibiotics and to suppress soilborne pathogens. Antibiotic production is often the mechanism of biocontrol by Streptomyces spp. This study focused on identifying unique volatile secondary metabolites produced by Streptomyces and their ability to inhibit plant pathogens. Volatiles are especially interesting because they diffuse through the air and can inhibit a target pathogen that is physically separated from the Streptomyces. The volatiles identified in this study had broad spectrum activity and were especially effective at suppressing the fungal pathogen Botrytis cinerea on strawberry. This fungus has one of the broadest range of hosts of any know pathogen.
Technical Abstract: Streptomyces spp. have the ability to produce a wide variety of secondary metabolites that interact with the environment. This study aimed to discover antifungal volatiles from the genus Streptomyces and to determine the mechanisms of inhibition. Volatiles identified from Streptomyces spp. included three major terpenes, geosmin, caryolan-1-ol and an unknown sesquiterpene. antiSMASH and KEGG predicted that the volatile terpene synthase gene clusters occur in the Streptomyces genome. Growth inhibition was observed when fungi were exposed to the volatiles. Biological activity of caryolan-1-ol has previously not been investigated. Fungal growth was inhibited in a dose-dependent manner by a mixture of the main volatiles, caryolan-1-ol and the unknown sesquiterpene, from Streptomyces sp. S4–7. Furthermore, synthesized caryolan-1-ol showed similar antifungal activity. Results of chemical-genomics profiling assays showed that caryolan-1-ol affected the endomembrane system by disrupting sphingolipid synthesis and normal vesicle trafficking in the fungi.