Antiviral activity and tobacco-induced resistance, mediated by essential oil nano-emulsions from Zataria multiflora and Satureja bakhtiarica

There has been a growing interest in extracting essential oils from aromatic plants as potential sources of biorational pesticides. In the present study, essential oil emulsions of Satureja bakhtiarica (SEO), Oliveria decumbens (OEO), Trachyspermum ammi (TEO) and Zataria multiflora (ZEO) were prepared. Their major chemical compositions were characterized and their antiviral effects were evaluated against two important plant viruses: Cucumber mosaic virus (CMV) and Tobacco mosaic virus (TMV). SEO and ZEO indicated higher antiviral activity in comparison with OEO and TEO (p < 0.05). In systemic bioassay, the pre-treatment test of ZEO and SEO showed a reduced level of TMV accumulation in TMV-infected tobacco, with rates of 26.75% and 23.97%, respectively. Also, the two essential oils had mechanisms by which plant resistance acted against plant viruses. These mechanisms involved the activities of several defense-related enzymes (PAL and POD) and genes (ICS1, NPR1, and PR-1a). These results indicate that the essential oils of Zataria multiflora and Satureja bakhtiarica have the potential to be used as sources of effective antiviral agents and eco-friendly pesticide.