Possible induction of potato plant defences against Potato virus Y by mineral oil application

In recent decades, mineral oil spray has been considered an effective means to reduce aphid-mediated spread of non-persistent viruses such as Potato virus Y (PVY). However, the mechanism by which mineral oil prevents viral outbreaks is not well-characterized. Despite the fact that several studies have investigated the effects of mineral oil on aphid feeding behaviour, vector fitness and virus attachment to vector mouthparts, the effect of oil treatment on the plant response has not been studied. To address this need, the current study has assessed the impact of Vazyl-Y mineral oil on the plant-vector-virus (i.e. potato-aphid-PVY) pathosystem in potato, with a particular focus on the plant response. These results show for the first time that oil treatment induces the expression of plant-virus interaction related genes in both local and systemic non-infected tissues, as well as in PVY-infected plants. Finally, the oil’s elicitation properties in reducing viral infectivity are discussed.