Ethylene signaling mediates potyvirus spread by aphid vectors.

Plant pathogens can influence host characteristics such as volatile emissions, nutrient composition or plant color, modulating vector and non-vector insect dynamics in the ecosystem. While previous research has focused on insect attraction and dispersal to infected plants, little is known about mechanisms mediating these interactions. Here, we investigate the role of ethylene in green peach aphid (Myzus persicae) attraction to potyvirus-infected plants. In our experiments, we utilized two different potyviruses, Potato virus Y (PVY) and Turnip mosaic virus, in lab and field experiments. Consistent with previous studies, we show that greater numbers of aphids settle on potyvirus-infected plants in the lab and greater numbers of aphids are found in PVY-infected potato (Solanum tuberosum) fields compared to controls. In laboratory experiments, inhibition of ethylene signaling in plants either chemically or genetically prevented aphids from preferentially settling on potyvirus-infected plants. Virus spread was reduced in lab arenas by over 80% when ethylene signaling was inhibited chemically. Despite this, ethylene inhibition had no significant impact on virus spread in field mesocosms. Our results indicate that induction of ethylene signaling by potyviruses mediates aphid attraction to infected plants and virus spread; however, additional factors may contribute to plant-vector dynamics in complex communities. Specific components of ethylene signaling may be important targets for future management of vector-borne viruses and research on mechanisms mediating plant-vector-virus interactions.