scholarly journals A highly infective plant-associated bacterium influences reproductive rates in pea aphids

2016 ◽  
Vol 3 (2) ◽  
pp. 150478 ◽  
Author(s):  
Tory A. Hendry ◽  
Kelley J. Clark ◽  
David A. Baltrus
Keyword(s):  
Pseudomonas Syringae ◽  
Acyrthosiphon Pisum ◽  
Dependent Manner ◽  
Bacterial Cells ◽  
Pea Aphids ◽  
Survival And Reproduction ◽  
Fecundity Compensation ◽  
Reproductive Rates ◽  
High Doses ◽  
Aphid Pathogen

Pea aphids, Acyrthosiphon pisum , have the potential to increase reproduction as a defence against pathogens, though how frequently this occurs or how infection with live pathogens influences this response is not well understood. Here we determine the minimum infective dose of an environmentally common bacterium and possible aphid pathogen, Pseudomonas syringae , to determine the likelihood of pathogenic effects to pea aphids. Additionally, we used P. syringae infection to investigate how live pathogens may alter reproductive rates. We found that oral bacterial exposure decreased subsequent survival of aphids in a dose-dependent manner and we estimate that ingestion of less than 10 bacterial cells is sufficient to increase aphid mortality. Pathogen dose was positively related to aphid reproduction. Aphids exposed to low bacterial doses showed decreased, although statistically indistinguishable, fecundity compared to controls. Aphids exposed to high doses reproduced significantly more than low dose treatments and also more, but not significantly so, than controls. These results are consistent with previous studies suggesting that pea aphids may use fecundity compensation as a response to pathogens. Consequently, even low levels of exposure to a common plant-associated bacterium may therefore have significant effects on pea aphid survival and reproduction.

scholarly journals Fight or Flight? Alternative Defense of the Pea Aphids, Acyrthosiphon pisum on Different Host Plants

Insects ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 614
Author(s):  
Martin John Martin ◽  
Yueming Li ◽  
Li Ma ◽  
Yi Feng ◽  
Zhiqiang Lu
Keyword(s):  
Host Plant ◽  
Host Plants ◽  
Acyrthosiphon Pisum ◽  
Fungal Infections ◽  
Alternative Strategies ◽  
Immunological Responses ◽  
Offspring Production ◽  
Broad Beans ◽  
Pea Aphids ◽  
Fecundity Compensation

Non-immunological responses are important alternative strategies for animals to deal with pathogens. It has long been recognized that fecundity compensation and production of winged offspring are two common non-immunological responses used by aphids when confronted with predators or pathogens. However, the effects of host plant on these responses have received little attention. This study investigated the effects of host plant on non-immunological defense in the pea aphids, Acyrthosiphon pisum, after bacterial and fungal infections. The aphids were raised in two groups, with one group being raised on broad beans and the other group being raised on alfalfa. The secondary symbiont background was examined, and the aphids were then infected with bacteria and fungus to assess fecundity and winged offspring production. We found that aphids that had been fed alfalfa had fewer offspring than those fed broad beans. Alfalfa-fed aphids produced more winged offspring in response to S. aureus and B. bassiana infections. Our findings suggest that the host plant plays a key role in fecundity and winged offspring production in pea aphid colony.

Acute and chronic insecticidal activity of a new mannose-binding lectin from Allium porrum against Acyrthosiphon pisum via an artificial diet

2009 ◽  
Vol 141 (1) ◽  
pp. 95-101 ◽  
Author(s):  
Amin Sadeghi ◽  
J.M. Van Damme ◽  
Katrien Michiels ◽  
Anita Kabera ◽  
Guy Smagghe
Keyword(s):  
Artificial Diet ◽  
Acyrthosiphon Pisum ◽  
Insect Pests ◽  
Integrated Management ◽  
Allium Porrum ◽  
Pea Aphids ◽  
Mannose Binding ◽  
Galanthus Nivalis ◽  
High Doses ◽  
Binding Lectin

AbstractIn view of the increasing use of plant proteins as valuable alternatives to chemical insecticides, the susceptibility of pea aphids, Acyrthosiphon pisum (Harris) (Hemiptera: Aphididae), to three purified mannose-binding plant lectins was determined in an artificial-diet bioassay. The insecticidal activities of a new lectin, APA (Allium porrum L. (Liliaceae) agglutinin) from garden leek, were compared with those of GNA (Galanthus nivalis L. (Liliaceae) agglutinin) from snowdrop and ASA (Allium sativum L. agglutinin) from cultivated garlic. GNA and ASA showed acute toxicity to first-instar nymphs; LC50 values for GNA and ASA were 350 and 700 µg/mL, respectively. With APA, mortality was scored only at high doses. In chronic experiments, however, lower doses significantly reduced survival and fecundity of adults (P < 0.05). Aphids fed a diet containing APA at 100, 500, and 750 µg/mL showed a significant delay in reaching adulthood and no aphids survived beyond 19 days of development. The data support the potential application of APA in the integrated management of insect pests.

scholarly journals The effect of parasitism by Aphidius ervi on development and reproduction of the pea aphid Acyrthosiphon pisum

2005 ◽  
Vol 58 ◽  
pp. 202-207 ◽  
Author(s):  
X.Z. He ◽  
Q. Wang ◽  
D.A.J. Teulon
Keyword(s):  
Generation Time ◽  
Acyrthosiphon Pisum ◽  
Adult Stage ◽  
Host Population ◽  
Reproductive Period ◽  
Pea Aphid ◽  
Aphidius Ervi ◽  
Survival And Reproduction ◽  
Potential Impact ◽  
Reproductive Rates

The effect of parasitism by Aphidius ervi Haliday (Hymenoptera Aphidiidae) on development survival and reproduction of pea aphid Acyrthosiphon pisum (Harris) (Hemiptera Aphididae) of different ages was studied in the laboratory Aphids parasitised when 1 and 2 days old (1st and 2nd instar) died at the 4th instar However those parasitised when 3 to 6 days old (3rd and 4th instar) could reach the adult stage following parasitism and those that were parasitised after 4 days old (late 3rd instar) were still able to produce progeny In comparison with the unparasitised aphids the parasitised aphids had a significantly shorter reproductive period and produced significantly fewer progeny and thus had significantly lower intrinsic rates of increase net reproductive rates shorter generation time and longer doubling time The potential impact of the parasitoid on host population growth is discussed

scholarly journals Insects as phyllosphere microbiome engineers: effects of aphids on a plant pathogen

2019 ◽  
Author(s):  
Melanie R. Smee ◽  
Imperio Real-Ramirez ◽  
Tory A. Hendry
Keyword(s):  
Pseudomonas Syringae ◽  
Acyrthosiphon Pisum ◽  
Waste Product ◽  
Insect Herbivores ◽  
Epiphytic Bacteria ◽  
Alternative Host ◽  
Associated Bacteria ◽  
Pea Aphids ◽  
Fitness Benefits ◽  
Diverse Plant

AbstractInsect herbivores are common in the phyllosphere, the above-ground parts of plants, and encounter diverse plant-associated bacteria there, yet how these organisms interact remains largely unknown. Strains of the bacterium Pseudomonas syringae grow well epiphytically and have been shown to grow within and kill hemipteran insects like the pea aphid, Acyrthosiphon pisum. Aphids are hypothesized to be an alternative host for these epiphytic bacteria but it is unclear if aphids provide fitness benefits to these bacterial pathogens. To determine if epiphytic bacteria could be adapted for infecting aphids, we characterized 21 strains of P. syringae for epiphytic ability and virulence to pea aphids and found that the two traits were positively correlated. For a subset of strains, we tested if the bacteria derived a fitness benefit from the presence of aphids. Some strains benefited significantly, with up to 18.9% higher population densities when aphids were present, and lower starting population density was predictive of higher benefit from aphid presence. However, further investigation found that honeydew, the sugary waste product of aphids, and not growth in aphids, increased P. syringae growth on leaves. This suggests that aphids may be important microbiome engineers in the phyllosphere, but evolutionarily dead-ends for epiphytic bacteria.

Melatonin actions in the heart; more than a hormone

2018 ◽  
Vol 1 (1) ◽  
pp. 21-26 ◽  
Author(s):  
Darío Acuña-Castroviejo ◽  
Maria T Noguiera-Navarro ◽  
Russel J Reiter ◽  
Germaine Escames
Keyword(s):  
Cell Membranes ◽  
Myocardial Cell ◽  
Rat Tissues ◽  
Dependent Manner ◽  
Broad Distribution ◽  
Multiple Organs ◽  
High Doses ◽  
Extrapineal Melatonin ◽  
Dose Dependent ◽  
Different Doses

Due to the broad distribution of extrapineal melatonin in multiple organs and tissues, we analyzed the presence and subcellular distribution of the indoleamine in the heart of rats. Groups of sham-operated and pinealectomized rats were sacrificed at different times along the day, and the melatonin content in myocardial cell membranes, cytosol, nuclei and mitochondria, were measured. Other groups of control animals were treated with different doses of melatonin to monitor its intracellular distribution. The results show that melatonin levels in the cell membrane, cytosol, nucleus, and mitochondria vary along the day, without showing a circadian rhythm. Pinealectomized animals trend to show higher values than sham-operated rats. Exogenous administration of melatonin yields its accumulation in a dose-dependent manner in all subcellular compartments analyzed, with maximal concentrations found in cell membranes at doses of 200 mg/kg bw melatonin. Interestingly, at dose of 40 mg/kg b.w, maximal concentration of melatonin was reached in the nucleus and mitochondrion. The results confirm previous data in other rat tissues including liver and brain, and support that melatonin is not uniformly distributed in the cell, whereas high doses of melatonin may be required for therapeutic purposes.

scholarly journals Decrease post-transplant relapse using donor-derived expanded NK-cells

Leukemia ◽  
2021 ◽  
Author(s):  
Stefan O. Ciurea ◽  
Piyanuch Kongtim ◽  
Doris Soebbing ◽  
Prashant Trikha ◽  
Gregory Behbehani ◽  
...  
Keyword(s):  
Nk Cells ◽  
Nk Cell ◽  
Ex Vivo ◽  
Disease Free Survival ◽  
Dependent Manner ◽  
Post Transplant ◽  
Haploidentical Transplantation ◽  
High Doses ◽  
High Level

AbstractIn this phase I/II clinical trial, we investigated the safety and efficacy of high doses of mb-IL21 ex vivo expanded donor-derived NK cells to decrease relapse in 25 patients with myeloid malignancies receiving haploidentical stem-cell transplantation (HSCT). Three doses of donor NK cells (1 × 105–1 × 108 cells/kg/dose) were administered on days −2, +7, and +28. Results were compared with an independent contemporaneously treated case-matched cohort of 160 patients from the CIBMTR database.After a median follow-up of 24 months, the 2-year relapse rate was 4% vs. 38% (p = 0.014), and disease-free survival (DFS) was 66% vs. 44% (p = 0.1) in the cases and controls, respectively. Only one relapse occurred in the study group, in a patient with the high level of donor-specific anti-HLA antibodies (DSA) presented before transplantation. The 2-year relapse and DFS in patients without DSA was 0% vs. 40% and 72% vs. 44%, respectively with HR for DFS in controls of 2.64 (p = 0.029). NK cells in recipient blood were increased at day +30 in a dose-dependent manner compared with historical controls, and had a proliferating, mature, highly cytotoxic, NKG2C+/KIR+ phenotype.Administration of donor-derived expanded NK cells after haploidentical transplantation was safe, associated with NK cell-dominant immune reconstitution early post-transplant, preserved T-cell reconstitution, and improved relapse and DFS. TRIAL REGISTRATION: NCT01904136 (https://clinicaltrials.gov/ct2/show/NCT01904136).

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

2006 ◽  
Vol 72 (3) ◽  
pp. 1956-1965 ◽  
Author(s):  
Anne-Marie Grenier ◽  
Gabrielle Duport ◽  
Sylvie Pagès ◽  
Guy Condemine ◽  
Yvan Rahbé
Keyword(s):  
Acyrthosiphon Pisum ◽  
Ecological Impact ◽  
Sitophilus Oryzae ◽  
Pea Aphid ◽  
Erwinia Chrysanthemi ◽  
Future Research ◽  
Close Relative ◽  
Bacterial Cells ◽  
Dickeya Dadantii ◽  
Phytopathogenic Bacterium

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.

Viability and respiratory activity ofPseudomonas syringaecells starved in buffer

1995 ◽  
Vol 41 (4-5) ◽  
pp. 372-377 ◽  
Author(s):  
João P. S. Cabral
Keyword(s):  
Oxygen Consumption ◽  
Electron Transport ◽  
Pseudomonas Syringae ◽  
Respiratory Activity ◽  
Bacterial Cells ◽  
Intact Cells ◽  
Rate Of Oxygen Consumption ◽  
Metabolic Activities ◽  
Different Levels ◽  
Number Of Cells

Pseudomonas syringae cells starved in buffer released orcinol-reactive molecules and materials that absorbed ultraviolet light. The number of cells culturable in nutrient medium decreased more rapidly than the number of intact particles determined by microscopy. The results suggested that starvation resulted in the lysis of an increasing number of cells, and that a fraction of the intact particles were not culturable. Starvation also resulted in a decrease in the rate of oxygen consumption with acetate, glycerol, and succinate, but at different levels. Whereas the respiration of acetate and glycerol decreased concomitantly with culturability, the respiration of succinate decreased to levels similar to the concentration of intact cells, suggesting that all intact particles respired the succinate, but only the culturable cells respired the acetate and glycerol. The results suggest that measuring the activity of the electron-transport system can overestimate the viability of starved bacterial cells, and that complex metabolic activities such as the respiration of acetate and glycerol are probably better suited for the evaluation of this parameter.Key words: Pseudomonas syringae, starvation, culturability, viability, respiration.

scholarly journals Effects of atmospheric conditions on ice nucleation activity of <i>Pseudomonas</i>

2012 ◽  
Vol 12 (22) ◽  
pp. 10667-10677 ◽  
Author(s):  
E. Attard ◽  
H. Yang ◽  
A.-M. Delort ◽  
P. Amato ◽  
U. Pöschl ◽  
...  
Keyword(s):  
Environmental Factors ◽  
Pseudomonas Syringae ◽  
Ice Nucleation ◽  
Acidic Ph ◽  
Bacterial Cells ◽  
Atmospheric Conditions ◽  
Ice Nucleation Protein ◽  
Ice Melt ◽  
Nucleation Activity ◽  
Ice Nucleation Activity

Abstract. Although ice nuclei from bacterial origin are known to be efficient at the highest temperatures known for ice catalysts, quantitative data are still needed to assess their role in cloud processes. Here we studied the effects of three typical cloud conditions (i) acidic pH (ii) NO2 and O3 exposure and (iii) UV-A exposure on the ice nucleation activity (INA) of four Pseudomonas strains. Three of the Pseudomonas syringae strains were isolated from cloud water and the phyllosphere and Pseudomonas fluorescens strain CGina-01 was isolated from Antarctic glacier ice melt. Among the three conditions tested, acidic pH caused the most significant effects on INA likely due to denaturation of the ice nucleation protein complex. Exposure to NO2 and O3 gases had no significant or only weak effects on the INA of two P. syringae strains whereas the INA of P. fluorescens CGina-01 was significantly affected. The INA of the third P. syringae strain showed variable responses to NO2 and O3 exposure. These differences in the INA of different Pseudomonas suggest that the response to atmospheric conditions could be strain-specific. After UV-A exposure, a substantial loss of viability of all four strains was observed whereas their INA decreased only slightly. This corroborates the notion that under certain conditions dead bacterial cells can maintain their INA. Overall, the negative effects of the three environmental factors on INA were more significant at the warmer temperatures. Our results suggest that in clouds where temperatures are near 0 °C, the importance of bacterial ice nucleation in precipitation processes could be reduced by some environmental factors.

Intracerebroventricular injection of prostaglandin E2 increases splenic sympathetic nerve activity in rats

1995 ◽  
Vol 269 (3) ◽  
pp. R662-R668 ◽  
Author(s):  
T. Ando ◽  
T. Ichijo ◽  
T. Katafuchi ◽  
T. Hori
Keyword(s):  
Prostaglandin E2 ◽  
Sympathetic Nerve ◽  
Time Course ◽  
Sympathetic Nerve Activity ◽  
Dependent Manner ◽  
Central Administration ◽  
Nerve Activity ◽  
High Doses ◽  
Alpha Chloralose ◽  
Dose Dependent

The effects of central administration of prostaglandin E2 (PGE2) and its selective agonists on splenic sympathetic nerve activity (SNA) were investigated in urethan- and alpha-chloralose-anesthetized rats. An intra-third-cerebroventricular (13V) injection of PGE2 (0.1-10 nmol/kg) increased splenic SNA in a dose-dependent manner. An I3V injection of an EP1 agonist, 17-phenyl-omega-trinor PGE2 (1-30 nmol/kg), also resulted in a dose-dependent increase in splenic SNA, with a time course similar to that of PGE2-induced responses. In contrast, EP2 agonists, butaprost (10-100 nmol/kg I3V) and 11-deoxy-PGE1 (10-100 nmol/kg I3V), had no effect on splenic SNA. An I3V injection of M & B-28767 (an EP3/EP1 agonist, EP3 >> EP1) increased splenic SNA only at high doses (10-100 nmol/kg). Pretreatment with an EP1 antagonist, SC-19220 (200 and 500 nmol/kg), completely blocked the responses of splenic SNA to PGE2 (0.1 nmol/kg) and M & B-28767 (10 nmol/kg), respectively. These findings indicate that brain PGE2 increases splenic SNA through its action on EP1 receptors.

Sign in / Sign up

Export Citation Format

Share Document