scholarly journals The aphid BCR4 structure and activity uncover a new defensin peptide superfamily

2021 ◽  
Author(s):  
Karine Loth ◽  
Nicolas Parisot ◽  
Francoise Paquet ◽  
Catherine Sivignon ◽  
Isabelle Rahioui ◽  
...  
Keyword(s):  
Acyrthosiphon Pisum ◽  
3D Structure ◽  
Pea Aphid ◽  
Symbiotic Bacteria ◽  
Structural Class ◽  
New Class ◽  
Agricultural Plants ◽  
Nymphal Growth ◽  
Structure And Activity ◽  
Potential Use

Aphids (Hemiptera: Aphidoidea) are among the most injuring insects for agricultural plants and their management is a great challenge in agronomical research. A new class of proteins, called Bacteriocyte-specific Cysteine-Rich (BCR), provides an alternative to chemical insecticides for pest control. BCRs have been initially identified in the pea aphid Acyrthosiphon pisum. They are small disulfide bond-rich proteins expressed exclusively in aphid bacteriocytes, the insect derived cells that host intracellular symbiotic bacteria. Here, we show that one out of the A. pisum BCRs, BCR4, displays an outstanding insecticidal activity against the pea aphid, impairing insect survival and nymphal growth, providing evidence for its potential use as a new biopesticides. Our comparative genomics and phylogenetic analysis indicate that BCRs seem restricted to the aphid lineage. The 3D structure of the BCR4 reveals that this peptide belongs to a yet unknown structural class of peptides and defines a new superfamily of defensins.

scholarly journals Infection Dynamic of Symbiotic Bacteria in the Pea Aphid Acyrthosiphon pisum Gut and Host Immune Response at the Early Steps in the Infection Process

PLoS ONE ◽  
2015 ◽  
Vol 10 (3) ◽  
pp. e0122099 ◽  
Author(s):  
François Renoz ◽  
Christine Noël ◽  
Abdelmounaim Errachid ◽  
Vincent Foray ◽  
Thierry Hance
Keyword(s):  
Immune Response ◽  
Acyrthosiphon Pisum ◽  
Host Immune Response ◽  
Infection Process ◽  
Pea Aphid ◽  
Symbiotic Bacteria ◽  
Infection Dynamic

scholarly journals Evidence for specificity in symbiont-conferred protection against parasitoids

2015 ◽  
Vol 282 (1811) ◽  
pp. 20150977 ◽  
Author(s):  
Ailsa H. C. McLean ◽  
H. Charles J. Godfray
Keyword(s):  
Genetic Diversity ◽  
Host Plants ◽  
Acyrthosiphon Pisum ◽  
Pea Aphid ◽  
Aphidius Ervi ◽  
Symbiotic Bacteria ◽  
Parasitoid Wasps ◽  
Bacterial Symbionts ◽  
Wasp Species ◽  
Hamiltonella Defensa

Many insects harbour facultative symbiotic bacteria, some of which have been shown to provide resistance against natural enemies. One of the best-known protective symbionts is Hamiltonella defensa , which in pea aphid ( Acyrthosiphon pisum ) confers resistance against attack by parasitoid wasps in the genus Aphidius (Braconidae). We asked (i) whether this symbiont also confers protection against a phylogenetically distant group of parasitoids (Aphelinidae) and (ii) whether there are consistent differences in the effects of bacteria found in pea aphid biotypes adapted to different host plants. We found that some H. defensa strains do provide protection against an aphelinid parasitoid Aphelinus abdominalis. Hamiltonella defensa from the Lotus biotype provided high resistance to A. abdominalis and moderate to low resistance to Aphidius ervi , while the reverse was seen from Medicago biotype isolates. Aphids from Ononis showed no evidence of symbiont-mediated protection against either wasp species and were relatively vulnerable to both. Our results may reflect the different selection pressures exerted by the parasitoid community on aphids feeding on different host plants, and could help explain the maintenance of genetic diversity in bacterial symbionts.

scholarly journals The reproductive system of the male and oviparous female of a model organism—the pea aphid, Acyrthosiphon pisum (Hemiptera, Aphididae)

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e7573 ◽  
Author(s):  
Karina Wieczorek ◽  
Mariusz Kanturski ◽  
Cezary Sempruch ◽  
Piotr Świątek
Keyword(s):  
Epithelial Cells ◽  
Reproductive System ◽  
Acyrthosiphon Pisum ◽  
Fluorescent Microscopy ◽  
Ejaculatory Duct ◽  
Pea Aphid ◽  
Cultivated Plants ◽  
Symbiotic Bacteria ◽  
Accessory Glands ◽  
Sexual Generation

The structure of the reproductive system of the sexual generation—males and oviparous females—of the pea aphid Acyrthosiphon pisum (Harris) (Hemiptera, Aphididae), a serious pest of cultivated plants of Fabaceae, was investigated. For the first time we describe the morphology, histology and ultrastructure of the reproductive system in both morphs of the sexual generation of aphids within one species, using light and fluorescent microscopy, as well as transmission and scanning electron microscopy. The results revealed that males have testes composed of three follicles fused by the upper ends of the vasa efferentia, the vasa deferentia run independently, the accessory glands are asymmetric and the ejaculatory duct shortened. Oviparous females have ovaries composed of seven ovarioles each. The lateral oviducts join to a short common oviduct connected with the unpaired spermatheca and paired accessory glands. Yolky eggs with an aggregation of symbiotic bacteria at the posterior pole are produced. Histologically, the components of genital tracts are broadly similar: the epithelial cells of the walls of the vasa deferentia and accessory glands of the male and oviparous female have secretory functions which correlate with the age of the studied morphs. We also found symbiotic bacteria within the vasa deferentia epithelial cells in males and within the cells of the lateral oviducts of females. Because the pea aphid is listed among the 14 species that are of the greatest economic importance, our results will be useful for managing aphid populations, protecting plants and ensuring global food security.

Honeydew sugars and osmoregulation in the pea aphid Acyrthosiphon pisum

1997 ◽  
Vol 200 (15) ◽  
pp. 2137-2143 ◽  
Author(s):  
T Wilkinson ◽  
D Ashford ◽  
J Pritchard ◽  
A Douglas
Keyword(s):  
Osmotic Pressure ◽  
Vicia Faba ◽  
Acyrthosiphon Pisum ◽  
Sucrose Concentration ◽  
Pea Aphid ◽  
Symbiotic Bacteria ◽  
Low Concentrations ◽  
Pea Aphids ◽  
High Concentrations ◽  
Aphid Honeydew

Pea aphids, Acyrthosiphon pisum, containing their symbiotic bacteria (untreated aphids) and experimentally deprived of their bacteria by treatment with the antibiotic rifampicin (antibiotic-treated aphids) were reared on the plant Vicia faba. The sugars in the honeydew produced by untreated aphids comprised predominantly the monosaccharides glucose and fructose, while the honeydew of antibiotic-treated aphids contained considerable amounts of oligosaccharides of up to 16 hexose units. The honeydew and haemolymph of the aphids were iso-osmotic, and their osmotic pressure was significantly lower in untreated aphids (0.91­0.95 MPa) than in antibiotic-treated aphids (1.01­1.05 MPa) (P<0.05). For insects reared on chemically defined diets containing 0.15­1.0 mol l-1 sucrose (osmotic pressure 1.1­4.0 MPa), the osmotic pressure of the aphid haemolymph did not vary with dietary osmotic pressure, but was regulated to approximately 1.0 MPa in untreated and 1.3 MPa in antibiotic-treated aphids. The sugars in the aphid honeydew varied with dietary sucrose concentration; with monosaccharides dominant at low concentrations and oligosaccharides dominant at high concentrations of dietary sucrose. The lowest dietary sucrose concentration at which honeydew oligosaccharides were detected was 0.2 mol l-1 for the antibiotic-treated aphids and 0.3 mol l-1 for untreated aphids. These data indicate that the aphid, and not its associated microbiota, mediates the synthesis of oligosaccharides when the osmotic pressure of the ingesta is high.

scholarly journals Repellent Effect of Basil (<em>Ocimum</em> spp) on Pea Aphid (<em>Acyrthosiphon pisum</em> Harris) and Potential Use in Crops

2021 ◽  
Author(s):  
Boni Barthélémy YAROU ◽  
Thomas Bawin ◽  
Françoise Assogba-Komlan ◽  
Armel G. C. Mensah ◽  
Frédéric Francis
Keyword(s):  
Acyrthosiphon Pisum ◽  
Pea Aphid ◽  
Repellent Effect ◽  
Potential Use

scholarly journals Trehalose and glucose levels regulate feeding behavior of the phloem-feeding insect, the pea aphid Acyrthosiphon pisum Harris

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Guang Wang ◽  
Jing-Jiang Zhou ◽  
Yan Li ◽  
Yuping Gou ◽  
Peter Quandahor ◽  
...  
Keyword(s):  
Feeding Behavior ◽  
Growth And Development ◽  
Acyrthosiphon Pisum ◽  
Pea Aphid ◽  
Feeding Time ◽  
Electrical Penetration Graph ◽  
Glucose Content ◽  
Glucose Levels ◽  
Phloem Feeding ◽  
Trehalose Content

AbstractTrehalose serves multifarious roles in growth and development of insects. In this study, we demonstrated that the high trehalose diet increased the glucose content, and high glucose diet increased the glucose content but decreased the trehalose content of Acyrthosiphon pisum. RNA interference (RNAi) of trehalose-6-phosphate synthase gene (ApTPS) decreased while RNAi of trehalase gene (ApTRE) increased the trehalose and glucose contents. In the electrical penetration graph experiment, RNAi of ApTPS increased the percentage of E2 waveform and decreased the percentage of F and G waveforms. The high trehalose and glucose diets increased the percentage of E2 waveform of A. pisum red biotype. The correlation between feeding behavior and sugar contents indicated that the percentage of E1 and E2 waveforms were increased but np, C, F and G waveforms were decreased in low trehalose and glucose contents. The percentage of np, E1 and E2 waveforms were reduced but C, F and G waveforms were elevated in high trehalose and glucose contents. The results suggest that the A. pisum with high trehalose and glucose contents spent less feeding time during non-probing phase and phloem feeding phase, but had an increased feeding time during probing phase, stylet work phase and xylem feeding phase.

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