Investigation of antifungal activities of myrcene on Fusarium reference strains

Abstract

Antifungal efects of myrcene, the plant-based naturel compound, were investigated on Fusarium graminearum PH-1 and Fusarium culmorum FcUK99 references, for the first time. Minimum inhibitory concentration (MIC) and half of MIC (MIC50) of both Fusarium strains against myrcene were found as 25µg/µl and 12.5µg/µl, respectively. MIC50 application decreased the cell viabilities in the ratios of 34.90% and 33.91% in PH-1 and FcUK99, respectively (p <0.01). The signifcantly increased catalase (CAT) activity was recorded in MIC50 treated strains (p<0.01). Apoptosis-like process and cellular oxidative stress were also monitored with acridine orange/ethidium bromide (Ao/Eb) dual staining and 2′,7′-dichlorodihydrofuorescein diacetate (DCF-DA) staining. The genomic template stability (GTS) percentages were calculated as 79% for PH-1 and 71% for FcUK99 via random amplifed polymorphic DNA (RAPD). Methylation polymorphism values were calculated as 53.8% and 50.6% in PH-1 and 40.4% and 39% in FcUK99 for HapII and MspI, respectively by coupled restriction enzyme digestion-random amplifcation (CRED-RA). Methylation-sensitive amplifed polymorphism (MSAP) revealed that myrcene caused both type I and type III epigenetic modifcations in both genomes. MIC50 dose caused up to 13.86±0.42-fold changes in the expressions of cat, mst20, and stuA, whereas downregulation in tri5 was recorded. Myrcene application did not change the retrotransposon movement in both species by the amplifying of idiomorphic retrotransposon patterns through inter-retrotransposon polymorphism-polymerase chain reaction (IRAP-PCR). This study demonstrated that myrcene is an efective compound in the management of phytopathogenic Fusarium species by causing morphological, genetic, epigenetic, and cellular alterations, and has a potential to utilize as an antifungal agent.