Antifungal activity of 8-methoxynaphthalen-1-ol isolated from the endophytic fungus Diatrype palmicola MFLUCC 17-0313 against the plant pathogenic fungus Athelia rolfsii on tomatoes

Abstract

Thirty-four endophytic fungal isolates were obtained from the leaves of the medicinal plant Polyscias fruticosa, and their antagonistic activities against the growth of the common tomatoes plant pathogenic fungus Athelia rolfsii were initially screened using a dual culture assay. The endophytic fungus MFLUCC 17-0313, which was later molecularly identified as Diatrype palmicola, displayed the highest inhibition percentage (49.98%) in comparison to the others. This fungus was then chosen for further evaluation. Its culture broth and mycelia from a 10 L scale were separated and extracted using ethyl acetate, methanol, and hexane. Each extract was tested for antifungal activity against the same pathogen using a disc diffusion assay. Only the crude hexane extract of fungal mycelium showed antifungal activity. The hexane extract was fractioned using sephadex gel filtration chromatography and each fraction was tested for antifungal activity until the one with the highest inhibition percentage was obtained. The bioactive compound was identified as 8-methoxynaphthalen-1-ol using nuclear magnetic resonance spectroscopy and mass spectrometry. The minimum inhibition concentration of 8-methoxynaphthalen-1-ol was demonstrated at 250 µg/mL against the selected pathogen. Using the leaf assay, the solution of 8-methoxynapthalen-1-ol was tested for phytotoxic activity against A. rolfsii and was found to have no phytotoxic effects. These results showed that 8-methoxynaphthalen-1-ol has the potential for controlling the growth of A. rolfsii, the cause of Southern blight disease on tomatoes. This study may provide the foundation for future use of this compound as a biofungicide.

In vitro and in vivo antifungal activity of Cuminum cyminum essential oil against Aspergillus aculeatus causing bunch rot of postharvest grapes

“…In addition, the species level of isolated fungus was identified using molecular technique. The genomic DNA of isolated fungus was also extracted using a method of Tanapichatsakul et al [ 24 ]. obtained sequences were compared to all sequences deposited in the National Center for Biotechnology Information database.…”

Antifungal properties of volatile organic compounds produced by Daldinia eschscholtzii MFLUCC 19-0493 isolated from Barleria prionitis leaves against Colletotrichum acutatum and its post-harvest infections on strawberry fruits

“…The aerial mycelium of C. acutatum isolate was scraped from the PDA surface and pulverized with a mortar and pestle to achieve a mycelium pulp. The genomic DNA was extracted following a protocol described by Tanapichatsakul et al (2020). The internal transcribed spacer (ITS) region was amplified using ITS5/ITS4 primers (Tanapichatsakul et al, 2020).…”

“…The genomic DNA was extracted following a protocol described by Tanapichatsakul et al (2020). The internal transcribed spacer (ITS) region was amplified using ITS5/ITS4 primers (Tanapichatsakul et al, 2020). Polymerase chain reactions (PCR) were performed following a protocol described by Tanapichatsakul et al (2020).…”

“…The internal transcribed spacer (ITS) region was amplified using ITS5/ITS4 primers (Tanapichatsakul et al, 2020). Polymerase chain reactions (PCR) were performed following a protocol described by Tanapichatsakul et al (2020). The sequence similarity of isolated fungi from BLAST result was 100% to C. acutatum.…”

“…Genomic DNA of endophytic isolate BP11 was extracted using a Genomic DNA Extraction Mini-Kit following the method of Tanapichatsakul et al (2020). DNA loci including ITS, LSU, and RPB2 regions were amplified by PCR following the protocol of Samarakoon et al (2019).…”