Project description:The pea aphid, Acyrthosiphon pisum, can host different facultative symbionts (FS), which may provide various benefits to the host, including adaptation to the host plant and resistance to heat or natural enemies (fungi, bacteria, parasitoid wasps). Here, we searched whether and how the presence of some FS could affect a key component of insect innate immunity, the phenoloxidase, under normal and stressed conditions. For this, we used A. pisum clones of different genetic background (LL01, YR2 and T3-8V1) and harboring or not FS (Regiella insecticola (Ri), Hamiltonella defensa (Hd) or Serratia symbiotica (Ss)). Proteomic analysis of aphid hemolymph and PCR indicated that the two A. pisum phenoloxidases, PO1 and PO2, are expressed and translated into protein. They seem mainly secreted as circulating enzymes in the hemolymph and a proteolytic cleavage was not necessary for their activation. PO genes expression was dependent upon the aphid genotypes as well as the amount of PO proteins and activity in the total hemolymph (T3-8V1-Amp > LL01 = YR2-Amp). The presence in YR2 and T3-8V1 clones of Hd or Ri, but not Ss, caused a sharp decrease in PO activity by interfering with both transcription and translation. Microinjection of different types of stressors (yeast, E. coli, latex beads) in YR2 lines affected the survival rate of aphids and in most cases, it also decreases the PO genes expression after 24h, whereas the amount and activity of the proteins varied differently depending on the FS and the stressor, regardless of the genes expression. These data provide new hypothesis on the mechanism by which some facultative symbionts act on the pea aphid immunity.

2024-04-29 | PXD018826 | Pride

Cuticular structure proteomics analyses of the pea aphid Acyrthosiphon pisum

Project description:Aphids are sap-feeding insects with piercing-sucking mouthparts. They are serious pests in agriculture and provoke significant losses, with a formidable capacity to transmit numerous plant viruses causing diseases in almost all important crops. The majority of viruses are acquired after feeding on an infected plant, retained on the aphid’s stylet and inoculated to healthy ones with a single probing puncture, promoting viral outbreaks. We have recently discovered the acrostyle, an organ located at the tip of aphid maxillary stylets, that harbors the receptors for Cauliflower Mosaic Virus (CaMV), and likely those for numerous other viruses. To our opinion, establishing an exhaustive inventory of the cuticular proteins composing the acrostyle, defining the peptide motifs accessible at the surface, identifying virus receptors among these proteins, will contribute to better understand virus/vector and plant/insect interactions at different scales including the molecular level. In this manuscript, we identify proteins or peptides at the surface of aphid stylets that might play a key role in plant virus binding. This may help to pave the way for future alternative “environmentally safe” strategies to control viral spread and aphid infestation in important crops worldwide.

2020-01-29 | PXD016517 | Pride

Phenotypic plasticity in the pea aphid Acyrthosiphon pisum: miRNA sequencing

Project description:Bioinformatic prediction, deep sequencing of microRNA and expression analysis during phenotypic plasticity in the pea aphid acyrthosiphon pisum We developed high throughput Solexa sequencing and bioinformatic analyses of the genome of the pea aphid Acyrthosiphon pisum in order to identify the first miRNAs from a hemipteran insect. By combining these methods we identified 155 miRNAs including 56 conserved and 99 new miRNAs. Moreover, we investigated the regulation of these miRNAs in different alternative morphs of the pea aphid by analysing the expression of miRNAs across the switch of reproduction mode.

2010-03-01 | GSE20107 | GEO

Phenotypic plasticity in the pea aphid Acyrthosiphon pisum: miRNA expression

Project description:We developed high throughput Solexa sequencing and bioinformatic analyses of the genome of the pea aphid Acyrthosiphon pisum in order to identify the first miRNAs from a hemipteran insect. By combining these methods we identified 155 miRNAs including 56 conserved and 99 new miRNAs. Moreover, we investigated the regulation of these miRNAs in different alternative morphs of the pea aphid by analysing the expression of miRNAs across the switch of reproduction mode.

2010-03-01 | GSE20106 | GEO