The potato aphid transcriptome and salivary secretome

The potato aphid, Macrosiphum euphorbiae, is an insect pest of plants mainly from the solanaceae family including potato and tomato. This aphid is a close relative of the pea aphid, Acyrthosiphon pisum, with a sequenced genome. In addition, resistance to this aphid is conferred by the tomato gene Mi-1, a member of the largest plant resistance protein family encoding CC-NBS-LRR. To characterize the tomato-potato aphid interactions, we developed transcriptome resources for this aphid. We used the Illumina’s next generation sequencing technology to profile the potato aphid transcriptome. Several mRNA-Seq libraries were generated from mixed developmental stages of the aphid exposed to susceptible or resistant tomato plants or subjected to starvation. These libraries were sequenced on Illumina’s GAII instrument using 76 base paired-end sequencing runs. Two main approaches were employed to generate a draft assembly of the potato aphid transcriptome. First, a de novo assembly was performed with the Velvet/Oases software. Second, the raw read-pairs were aligned to the pea aphid transcriptome. The consensus contigs obtained from both approaches were annotated by translated BLAST searches against the UniProt database. We used the potato aphid transcriptome database and mass spectrometry of potato aphid saliva to identify the aphid secretome. Currently, we are analyzing the functional roles of a subset of these secreted proteins.