Credit: K. MAUCK

Proc. Natl Acad. Sci. USA doi:10.1073/pnas.0907191107 (2010)

Many insect-borne plant pathogens alter the plants they infect in ways that enhance the pathogens' spread from plant to plant. Unlike some plant viruses, which are best transmitted if their insect carriers feed for a long time on the plant, the aphid-borne cucumber mosaic virus (CMV) is transmitted effectively only if aphids rapidly disperse to new susceptible plants.

To explore the interaction between CMV, its carriers and infected plants, Mark Mescher and his colleagues at Pennsylvania State University in University Park looked at how the virus affects the squash plant Cucurbita pepo and its interactions with two aphid carriers — Myzus persicae (pictured above) and Aphis gossypii.

The team discovered that the virus causes infected plants to release higher levels of volatile compounds than uninfected plants, thus attracting more aphids. The aphids then emigrate from the infected plants more quickly than from healthy plants, so increasing the chance of virus spread.