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,
<[www.isaaa.org]
load/biotech-crop-annual-update-maize-2018.pdf> 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.

[apsjournals.apsnet.org]