The Phytopathogen Dickeya dadantii (Erwinia chrysanthemi 3937) Is a Pathogen of the Pea Aphid

ABSTRACT Dickeya dadantii (Erwinia chrysanthemi) is a phytopathogenic bacterium causing soft rot diseases on many crops. The sequencing of its genome identified four genes encoding homologues of the Cyt family of insecticidal toxins from Bacillus thuringiensis, which are not present in the close relative Pectobacterium carotovorum subsp. atrosepticum. The pathogenicity of D. dadantii was tested on the pea aphid Acyrthosiphon pisum, and the bacterium was shown to be highly virulent for this insect, either by septic injury or by oral infection. The lethal inoculum dose was calculated to be as low as 10 ingested bacterial cells. A D. dadantii mutant with the four cytotoxin genes deleted showed a reduced per os virulence for A. pisum, highlighting the potential role of at least one of these genes in pathogenicity. Since only one bacterial pathogen of aphids has been previously described (Erwinia aphidicola), other species from the same bacterial group were tested. The pathogenic trait for aphids was shown to be widespread, albeit variable, within the phytopathogens, with no link to phylogenetic positioning in the Enterobacteriaceae. Previously characterized gut symbionts from thrips (Erwinia/Pantoea group) were also highly pathogenic to the aphid, whereas the potent entomopathogen Photorhabdus luminescens was not. D. dadantii is not a generalist insect pathogen, since it has low pathogenicity for three other insect species (Drosophila melanogaster, Sitophilus oryzae, and Spodoptera littoralis). D. dadantii was one of the most virulent aphid pathogens in our screening, and it was active on most aphid instars, except for the first one, probably due to anatomical filtering. The observed difference in virulence toward apterous and winged aphids may have an ecological impact, and this deserves specific attention in future research.

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Rickettsia Symbiont in the Pea Aphid Acyrthosiphon pisum: Novel Cellular Tropism, Effect on Host Fitness, and Interaction with the Essential Symbiont Buchnera

Applied and Environmental Microbiology ◽

10.1128/aem.71.7.4069-4075.2005 ◽

2005 ◽

Vol 71 (7) ◽

pp. 4069-4075 ◽

Cited By ~ 170

Author(s):

Makiko Sakurai ◽

Ryuichi Koga ◽

Tsutomu Tsuchida ◽

Xian-Ying Meng ◽

Takema Fukatsu

Keyword(s):

Acyrthosiphon Pisum ◽

Natural Populations ◽

Pea Aphid ◽

Host Cells ◽

Pcr Analysis ◽

Bacterial Cells ◽

Host Fitness ◽

Host Aphid ◽

Sheath Cells

ABSTRACT In natural populations of the pea aphid Acyrthosiphon pisum, a facultative bacterial symbiont of the genus Rickettsia has been detected at considerable infection frequencies worldwide. We investigated the effects of the Rickettsia symbiont on the host aphid and also on the coexisting essential symbiont Buchnera. In situ hybridization revealed that the Rickettsia symbiont was specifically localized in two types of host cells specialized for endosymbiosis: secondary mycetocytes and sheath cells. Electron microscopy identified bacterial rods, about 2 μm long and 0.5 μm thick, in sheath cells of Rickettsia-infected aphids. Virus-like particles were sometimes observed in association with the bacterial cells. By an antibiotic treatment, we generated Rickettsia-infected and Rickettsia-eliminated aphid strains with an identical genetic background. Comparison of these strains revealed that Rickettsia infection negatively affected some components of the host fitness. Quantitative PCR analysis of the bacterial population dynamics identified a remarkable interaction between the coexisting symbionts: Buchnera population was significantly suppressed in the presence of Rickettsia, particularly at the young adult stage, when the aphid most actively reproduces. On the basis of these results, we discussed the possible mechanisms that enable the prevalence of Rickettsia infection in natural host populations in spite of the negative fitness effects observed in the laboratory.

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Population Behavior Analysis of dspE and pelD Regulation in Erwinia chrysanthemi 3937

Molecular Plant-Microbe Interactions ◽

10.1094/mpmi-19-0451 ◽

2006 ◽

Vol 19 (4) ◽

pp. 451-457 ◽

Cited By ~ 29

Author(s):

Quan Peng ◽

Shihui Yang ◽

Amy O. Charkowski ◽

Mee-Ngan Yap ◽

Douglas A. Steeber ◽

...

Keyword(s):

Fluorescent Protein ◽

Erwinia Chrysanthemi ◽

Green Fluorescent Protein Gene ◽

Similar Proportion ◽

Bacterial Cells ◽

Potato Tubers ◽

Phytopathogenic Bacterium ◽

T3ss Effector ◽

Quantitative Results ◽

Green Fluorescent

Erwinia chrysanthemi 3937 (Ech3937) is a phytopathogenic bacterium with a wide host range. The pectinolytic enzymes secreted by the bacterium and the type III secretion system (T3SS) are essential for full virulence. We used the green fluorescent protein gene as a reporter to investigate the expression of dspE (a putative T3SS effector) and pelD (a major pectin-degrading enzyme) in populations of Ech3937 under different conditions. Gene expression was analyzed by measuring the fluorescence intensity of individual cells with a fluorescence-activated cell sorter. Ech3937 dspE was induced in minimal medium (MM) with only a portion of Ech3937 cells (43.03%) expressing dspE after 12 h of culture. The nutrient-rich King's medium B did not fully eliminate the expression of dspE; a small percentage of Ech3937 cells (5.55%) was able to express dspE after 12 h of culture in this medium. In all, 68.95% of Ech3937 cells expressed pelD after 12 h of culture in MM supplemented with polygalacturonic acid (PGA). However, 96.34% of Ech131 cells (an hrpL deletion mutant of Ech3937) expressed pelD after 12 h of culture in MM supplemented with PGA. In potato tubers, 6.32% of the bacterial cells expressed dspE 2 h after inoculation, whereas only 0.25% of the cells expressed pelD. However, after 24 h, the percentage of cells expressing pelD (68.48%) was approximately 3.5 times that of cells expressing dspE (19.39%). In contrast to potato tubers, similar proportion of Ech3937 cells expressing dspE (39.34%) and pelD (40.30%) were observed in Chinese cabbage 24 h after inoculation. From promoter activity and real-time quantitative results, the expression of pelD in Ech3937 was demonstrated to be downregulated by HrpL in MM supplemented with PGA.

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Dickeya dadantii, a Plant Pathogenic Bacterium Producing Cyt-Like Entomotoxins, Causes Septicemia in the Pea Aphid Acyrthosiphon pisum

PLoS ONE ◽

10.1371/journal.pone.0030702 ◽

2012 ◽

Vol 7 (1) ◽

pp. e30702 ◽

Cited By ~ 24

Author(s):

Denis Costechareyre ◽

Séverine Balmand ◽

Guy Condemine ◽

Yvan Rahbé

Keyword(s):

Acyrthosiphon Pisum ◽

Pathogenic Bacterium ◽

Pea Aphid ◽

Plant Pathogenic Bacterium ◽

Dickeya Dadantii

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Mechanical stimulation from plant contact and wind negatively impact pea aphids (Hemiptera: Aphididae) indirectly through host plants

The Canadian Entomologist ◽

10.4039/tce.2019.56 ◽

2019 ◽

Vol 151 (6) ◽

pp. 768-776

Author(s):

Tyler J. Follman ◽

Aleix Valls ◽

Katherine C. Kral-O’Brien ◽

Jason P. Harmon

Keyword(s):

Mechanical Stimulation ◽

Indirect Effects ◽

Acyrthosiphon Pisum ◽

Abiotic Factors ◽

Pea Aphid ◽

Future Research ◽

Global Changes ◽

Pea Aphids ◽

Aphid Fecundity ◽

Wind Patterns

AbstractGlobal change research has shown how altering factors like temperature and precipitation can impact insect ecology. However, despite global changes in wind patterns, the effects of altering wind have been relatively unexplored, and even less is understood about indirect effects on insects. To better understand indirect effects of wind on pea aphids (Acyrthosiphon pisum (Harris); Hemiptera: Aphididae), we performed two experiments using different techniques for simulating mechanical stimulation effects from wind. First, we used either a brush or leaf to simulate plant-to-plant contact caused by wind. Then we tested the indirect effects of wind by distinguishing between wind and wind plus plant contact produced by adjacent plants. In the first experiment, aphid fecundity was reduced on plants with the leaf-to-plant treatment compared to the control. In the second experiment, wind treatments reduced pea aphid fecundity, but wind did not interact with plant density. Our results further the idea that altering wind patterns can influence plant–insect interactions. We also show that more research is necessary to disentangle how and why wind indirectly influences herbivores. Future research should focus on how pea aphid responses to wind change due to the methodology of wind exposure and interactions with additional biotic and abiotic factors.

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

Scientific Reports ◽

10.1038/s41598-021-95390-z ◽

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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Efficacy of Botanical Insecticides against the Pea Aphid, Acyrthosiphon pisum (Harris) and Effect on Some of Its Natural Enemies on Field Pea in South Central Ethiopia

Science Technology and Arts Research Journal ◽

10.4314/star.v4i2.7 ◽

2016 ◽

Vol 4 (2) ◽

pp. 53 ◽

Cited By ~ 1

Author(s):

Lemmessa Gemmeda ◽

Gashawbeza Ayalew

Keyword(s):

Natural Enemies ◽

Acyrthosiphon Pisum ◽

Field Pea ◽

Pea Aphid ◽

Botanical Insecticides ◽

Central Ethiopia ◽

South Central

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Further evidence that mechanisms of host/symbiont integration are dissimilar in the maternal versus embryonic Acyrthosiphon pisum bacteriome

EvoDevo ◽

10.1186/s13227-020-00168-5 ◽

2020 ◽

Vol 11 (1) ◽

Author(s):

Celeste R. Banfill ◽

Alex C. C. Wilson ◽

Hsiao-ling Lu

Keyword(s):

Amino Acids ◽

Amino Acid ◽

Acyrthosiphon Pisum ◽

Essential Amino Acids ◽

Developmental Time ◽

Follicular Epithelium ◽

Future Research ◽

Buchnera Aphidicola ◽

Bacterial Endosymbionts ◽

Asexual Embryogenesis

Abstract Background Host/symbiont integration is a signature of evolutionarily ancient, obligate endosymbioses. However, little is known about the cellular and developmental mechanisms of host/symbiont integration at the molecular level. Many insects possess obligate bacterial endosymbionts that provide essential nutrients. To advance understanding of the developmental and metabolic integration of hosts and endosymbionts, we track the localization of a non-essential amino acid transporter, ApNEAAT1, across asexual embryogenesis in the aphid, Acyrthosiphon pisum. Previous work in adult bacteriomes revealed that ApNEAAT1 functions to exchange non-essential amino acids at the A. pisum/Buchnera aphidicola symbiotic interface. Driven by amino acid concentration gradients, ApNEAAT1 moves proline, serine, and alanine from A. pisum to Buchnera and cysteine from Buchnera to A. pisum. Here, we test the hypothesis that ApNEAAT1 is localized to the symbiotic interface during asexual embryogenesis. Results During A. pisum asexual embryogenesis, ApNEAAT1 does not localize to the symbiotic interface. We observed ApNEAAT1 localization to the maternal follicular epithelium, the germline, and, in late-stage embryos, to anterior neural structures and insect immune cells (hemocytes). We predict that ApNEAAT1 provisions non-essential amino acids to developing oocytes and embryos, as well as to the brain and related neural structures. Additionally, ApNEAAT1 may perform roles related to host immunity. Conclusions Our work provides further evidence that the embryonic and adult bacteriomes of asexual A. pisum are not equivalent. Future research is needed to elucidate the developmental time point at which the bacteriome reaches maturity.

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CORNICLE LENGTH AS A CRITERION FOR SEPARATING FIELD-COLLECTED NYMPHAL INSTARS OF THE PEA APHID, ACYRTHOSIPHON PISUM (HOMOPTERA: APHIDIDAE)

The Canadian Entomologist ◽

10.4039/ent1151615-12 ◽

1983 ◽

Vol 115 (12) ◽

pp. 1615-1619 ◽

Cited By ~ 7

Author(s):

William D. Hutchison ◽

David B. Hogg

Keyword(s):

Acyrthosiphon Pisum ◽

Pea Aphid ◽

Field Sample ◽

Rearing Temperature ◽

Multimodal Analysis

AbstractCornicle length measuremetns of Acyrthosiphon pisum (Harris) nymphs reared in the laboratory were instar-specific and unaffected by rearing temperature. A multimodal analysis of cornicle lengths of field-collected aphids clearly detected four distribution peaks (i.e., instars) in five different field populations, and there was generaaly little overlap between successive instar distributions. However, third and fourth instars in the spring field sample could not be separated accurately due to the shorter cornicle length of nymphs that developed from overwintered eggs. Cornicle length proved to be a useful criterion for separating virginoparous A. pisum instars in samples collected in southern Wisconsin.

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