Plant Virus and Insect Virus Connive for Greater Infestation

Aphids and the plant viruses they spread cause billions of dollars worth of crop damage globally every year. Scientists at the USDA Agricultural Research Service and Boyce Thompson Institute (BTI) are investigating this relationship at the molecular level with an objective of finding new ways to control the pests. Their findings are published in Phytobiomes Journal.

The researchers developed small RNA sequencing techniques to understand the relationship between plant viruses and aphids. They found a plant virus and an insect virus working together to increase the likelihood that both viruses will spread to other plant and aphid hosts. This relationship could be the first reported example of cooperation between a plant virus and an insect virus.

The study is centered on green peach aphid (Myzus persicae), which feeds on several crops such as peaches, tomatoes, potatoes, cabbage, corn, and many others, and has the capacity to transmit over a hundred plant viruses. There is high attention towards potato leafroll virus (PLRV) because it can cause up to 50% yield damage or 20 million tons of global yield losses in a year. They found that PLRV suppressed the aphid's immune system, and this suppression was mediated by a single virus protein (P0). P0 is a PLRV protein expressed in the plant tissue and not in the aphids. While P0 had been previously shown to suppress plants' immune systems, the protein's impact on the insect's immune system was a surprise to the researchers.

Read more results in Phytobiomes Journal and from BTI.