Transcriptomic analysis of intestinal genes following acquisition of pea enation mosaic virus by the pea aphid Acyrthosiphon pisum

Abstract

Viruses in the family Luteoviridae are strictly transmitted by aphids in a non-propagative, circulative and persistent mode. Virions ingested by aphids successively cross the gut and the accessory salivary gland epithelia before being released, together with saliva, into the plant vasculature. Virion transport through aphid cells occurs by a transcytosis mechanism. This study conducted a transcriptomic analysis of intestinal genes of the pea aphid Acyrthosiphon pisum following uptake of pea enation mosaic virus. Among the 7166 transcripts analysed, 128 were significantly regulated (105 genes downregulated and 23 upregulated). Of these genes, 5% were involved in intracellular trafficking, endocytosis and signal transduction, three important steps in the internalization and transport of virions. The limited levels of downregulation (maximum of 3.45-fold) and upregulation (maximum of 1.37-fold) suggest that the virus hijacks a constitutive endocytosis–exocytosis mechanism without heavily perturbing cell metabolism. Although limited to about 20% of the pea aphid genes, this work represents the first large-scale analysis of aphid gene regulation following virus acquisition. A better knowledge of this virus–vector interaction will be possible only when tools representing the complete genomic capacity of the aphid become available.