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Cecilia Tamborindeguy - One of the best experts on this subject based on the ideXlab platform.
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Global gene regulation in tomato plant (Solanum lycopersicum) responding to vector (Bactericera cockerelli) feeding and pathogen (‘Candidatus Liberibacter solanacearum’) infection
Plant Molecular Biology, 2018Co-Authors: Ordom Brian Huot, Julien Gad Levy, Cecilia TamborindeguyAbstract:Key message Different responses are elicited in tomato plants by Bactericera cockerelli harboring or not the pathogen ‘ Candidatus Liberibacter solanacearum’. Abstract ‘ Candidatus Liberibacter solanacearum’ (Lso) has emerged as a major pathogen of crops worldwide. This bacterial pathogen is transmitted by Bactericera cockerelli , the tomato psyllid, to solanaceous crops. In this study, the transcriptome profiles of tomato ( Solanum lycopersicum ) exposed to B. cockerelli infestation and Lso infection were evaluated at 1, 2 and 4 weeks following colonization and/or infection. The plant transcriptional responses to Lso-negative B. cockerelli were different than plant responses to Lso-positive B. cockerelli . The comparative transcriptome analyses of plant responses to Lso-negative B. cockerelli revealed the up-regulation of genes associated with plant defenses regardless of the time-point. In contrast, the general responses to Lso-positive B. cockerelli and Lso-infection were temporally different. Infected plants down-regulated defense genes at week one while delayed the up-regulation of the defense genes until weeks two and four, time points in which early signs of disease development were also detected in the transcriptional response. For example, infected plants regulated carbohydrate metabolism genes which could be linked to the disruption of sugar distribution usually associated with Lso infection. Also, infected plants down-regulated photosynthesis-related genes potentially resulting in plant chlorosis, another symptom associated with Lso infection. Overall, this study highlights that tomato plants induce different sets of genes in response to different stages of B. cockerelli infestation and Lso infection. This is the first transcriptome study of tomato responses to B. cockerelli and Lso, a first step in the direction of finding plant defense genes to enhance plant resistance.
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Global gene regulation in tomato plant (Solanum lycopersicum) responding to vector (Bactericera cockerelli) feeding and pathogen ('Candidatus Liberibacter solanacearum') infection.
Plant molecular biology, 2018Co-Authors: Ordom Brian Huot, Julien Gad Levy, Cecilia TamborindeguyAbstract:Different responses are elicited in tomato plants by Bactericera cockerelli harboring or not the pathogen 'Candidatus Liberibacter solanacearum'. 'Candidatus Liberibacter solanacearum' (Lso) has emerged as a major pathogen of crops worldwide. This bacterial pathogen is transmitted by Bactericera cockerelli, the tomato psyllid, to solanaceous crops. In this study, the transcriptome profiles of tomato (Solanum lycopersicum) exposed to B. cockerelli infestation and Lso infection were evaluated at 1, 2 and 4 weeks following colonization and/or infection. The plant transcriptional responses to Lso-negative B. cockerelli were different than plant responses to Lso-positive B. cockerelli. The comparative transcriptome analyses of plant responses to Lso-negative B. cockerelli revealed the up-regulation of genes associated with plant defenses regardless of the time-point. In contrast, the general responses to Lso-positive B. cockerelli and Lso-infection were temporally different. Infected plants down-regulated defense genes at week one while delayed the up-regulation of the defense genes until weeks two and four, time points in which early signs of disease development were also detected in the transcriptional response. For example, infected plants regulated carbohydrate metabolism genes which could be linked to the disruption of sugar distribution usually associated with Lso infection. Also, infected plants down-regulated photosynthesis-related genes potentially resulting in plant chlorosis, another symptom associated with Lso infection. Overall, this study highlights that tomato plants induce different sets of genes in response to different stages of B. cockerelli infestation and Lso infection. This is the first transcriptome study of tomato responses to B. cockerelli and Lso, a first step in the direction of finding plant defense genes to enhance plant resistance.
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Bactericera cockerelli vitellogenin-6 like, a vitellogenin without a direct reproductive function?
Insect molecular biology, 2017Co-Authors: Freddy Ibanez, Xiao-tian Tang, Cecilia TamborindeguyAbstract:Vitellogenin-like proteins are members of the large lipid transfer proteins, a family of proteins involved in reproduction, lipid circulation and immune defences. In this study, we identified a new Bactericera cockerelli vitellogenin-like (Vg-like) transcript, and named it BcVg6-like based on its similarity to Acyrthosiphon pisum Vg6. In silico analyses predicted different conserved domains in BcVg6-like compared with the conventional Ba. cockerelli vitellogenin, BcVg1-like, previously described by our research group. Phylogenetic analyses determined that BcVg6-like clustered with Vg-like-B proteins and not the conventional vitellogenins involved in vitellogenesis. Also, the expression analyses showed differences in BcVg6-like transcript expression between 7-day-old males and 3- and 7-day-old females. BcVg6-like was not upregulated after exogenous application of juvenile hormone III, but its relative expression increased significantly in alimentary canals of adult females exposed to tomato plants infected by the bacterial plant pathogen 'Candidatus Liberibacter solanacearum'. Our results suggest that in Ba. cockerelli, both vitellogenin genes may have different functions: BcVg1-like is a conventional vitellogenin that conserved its ancestral function as an egg yolk precursor whereas BcVg6-like might have acquired a function in lipid and/or other molecule transport, and could potentially play a role in immune defence.
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drought stress affects solanum lycopersicum susceptibility to Bactericera cockerelli colonization
Entomologia Experimentalis Et Applicata, 2017Co-Authors: Ordom Brian Huot, Cecilia TamborindeguyAbstract:Recent outbreaks in plant diseases associated with Liberibacter pathogens have impacted large areas of western and southern North America. The increase in frequency and severity of drought could render plants more susceptible to the colonization by insect vectors. Experiments were conducted in a laboratory setting to evaluate the influence of water scarcity on drought stress of tomato plants, Solanum lycopersicum L. (Solanaceae). Weekly water treatment of 200, 100, and 50 ml resulted in unstressed (control, Ψw = −0.55 MPa), lowly drought‐stressed (LDS, Ψw = −0.70 MPa), and moderately drought‐stressed (MDS, Ψw = −0.87 MPa) plants, respectively. By controlling for both water availability and plant drought stress, the effect of drought stress on S. lycopersicum susceptibility to potato psyllid, Bactericera cockerelli (Sulc) (Hemiptera: Triozidae), was evaluated. In a no‐choice experiment, MDS plants had significantly more B. cockerelli nymphs than control plants. However, plant susceptibility to B. cockerelli colonization was not due to the oviposition preference for MDS, but rather to the higher B. cockerelli nymphal survival on MDS than on control plants. Nymphal survival of B. cockerelli on MDS plants was consistently and significantly higher than on control plants. Throughout all nymphal stages, B. cockerelli had higher survival on MDS plants than on control plants. Drought stress not only enhanced B. cockerelli survival on S. lycopersicum but it also resulted in 60% more adults produced on water‐stressed plants than on control plants. Therefore, as adults can move from plant to plant, drought stress could increase B. cockerelli's dispersion potential. Although plant drought stress improved B. cockerelli survival, it did not affect B. cockerelli oviposition. No difference in number of offspring was found between B. cockerelli adults that developed on MDS vs. control plants. These results might be relevant to B. cockerelli outbreaks and Liberibacter epidemics.
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Identification and expression analyses of vitellogenin in Bactericera cockerelli (Šulc).
Journal of insect physiology, 2016Co-Authors: Freddy Ibanez, Julien Levy, Cecilia TamborindeguyAbstract:Abstract The potato psyllid, Bactericera cockerelli (Sulc) (Hemiptera: Triozidae), is a phloem-feeding insect with preference for Solanaceae. This insect species is vector of the pathogenic bacteria ‘Candidatus Liberibacter solanacearum’ the causative agent of zebra chip, an important disease of commercial potatoes in several countries worldwide. The recent classification of psyllids among the most dangerous vectors has promoted their study, but still many biological processes such as reproduction and vitellogenesis need to be investigated. As a first step towards the elucidation of vitellogenesis in B. cockerelli, one candidate vitellogenin transcript (6622 bases long) was identified and the expression of the transcript and the protein were analyzed in virgin and mated females between 1 and 7 days old. In virgin females, Vg expression increased up to 5 days old; while mating significantly up-regulated Vg expression in 5- and 7-day-old females. To determine the role of juvenile hormone in B. cockerelli Vg expression, topical applications of juvenile hormone III were performed on virgin females, resulting in an up-regulation of Vg expression and an increase in the number of mature oocytes present in female reproductive organs. Overall, this study represents the first step to understand vitellogenesis of B. cockerelli and it highlights the role of JH III in the hormonal regulation of Vg expression and oocyte development.
Joseph E. Munyaneza - One of the best experts on this subject based on the ideXlab platform.
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Role of ‘Candidatus Liberibacter solanacearum’ and Bactericera cockerelli Haplotypes in Zebra Chip Incidence and Symptom Severity
American Journal of Potato Research, 2018Co-Authors: Kylie D. Swisher Grimm, Tariq Mustafa, W. Rodney Cooper, Joseph E. MunyanezaAbstract:Dos haplotipos del patógeno “ Candidatus liberibacter solanacearum ” (Lso) y cuatro haplotipos del insecto vector, Bactericera cockerelli , están asociados con la enfermedad de la papa rayada. Lo que es la severidad de la enfermedad o la incidencia, y si están influenciadas por el haplotipo del patógeno o del insecto, esta pobremente entendido. Se analizó el papel de Lso “A” y “B”, transmitido por tres haplotipos de B. cockerelli en la severidad e incidencia de la enfermedad en ocho variedades de papa. Ambos haplotipos de Lso indujeron síntomas en el tubérculo. En general, Lso B causó mayor incidencia de síntomas y mayor reducción en tubérculos en comparación con Lso A. Lso B se asoció con síntomas más severos de tubérculo, produciendo pocos síntomas ligeros o moderados. Lso A se asoció con síntomas menos severos de tubérculo, a pesar de ser capaz de inducir síntomas severos. La incidencia de la enfermedad, el rendimiento de tubérculo y las calificaciones de severidad de síntomas no dependieron del haplotipo del psylido transmisor del patógeno, lo cual sugiere que el patógeno, no el haplotipo del insecto, afecta la transmisión del Lso. Two haplotypes of the pathogen, ‘ Candidatus Liberibacter solanacearum,’ (Lso) and four haplotypes of the insect vector, Bactericera cockerelli, are associated with zebra chip disease of potato. Whether disease severity or incidence is influenced by pathogen or insect haplotype is poorly understood. The role of Lso ‘A’ and ‘B,’ transmitted by three haplotypes of B. cockerelli, on disease severity and incidence in eight potato cultivars was analyzed. Both haplotypes of Lso induced tuber symptoms. In general, Lso B caused higher incidence of symptoms, and greater reduction in tubers compared with Lso A. Lso B was associated with more severe tuber symptoms, producing fewer mild or moderate tuber symptoms. Lso A was associated with less severe tuber symptoms, despite being able to induce severe symptoms. Disease incidence, tuber yield, and symptom severity ratings were not dependent upon the psyllid haplotype transmitting the pathogen, suggesting that pathogen, not insect haplotype affects Lso transmission.
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Role of ‘ Candidatus Liberibacter solanacearum’ and Bactericera cockerelli Haplotypes in Zebra Chip Incidence and Symptom Severity
American Journal of Potato Research, 2018Co-Authors: Kylie D. Swisher Grimm, W. Rodney Cooper, Tariq Mustafa, Joseph E. MunyanezaAbstract:Two haplotypes of the pathogen, ‘Candidatus Liberibacter solanacearum,’ (Lso) and four haplotypes of the insect vector, Bactericera cockerelli, are associated with zebra chip disease of potato. Whether disease severity or incidence is influenced by pathogen or insect haplotype is poorly understood. The role of Lso ‘A’ and ‘B,’ transmitted by three haplotypes of B. cockerelli, on disease severity and incidence in eight potato cultivars was analyzed. Both haplotypes of Lso induced tuber symptoms. In general, Lso B caused higher incidence of symptoms, and greater reduction in tubers compared with Lso A. Lso B was associated with more severe tuber symptoms, producing fewer mild or moderate tuber symptoms. Lso A was associated with less severe tuber symptoms, despite being able to induce severe symptoms. Disease incidence, tuber yield, and symptom severity ratings were not dependent upon the psyllid haplotype transmitting the pathogen, suggesting that pathogen, not insect haplotype affects Lso transmission.
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role of candidatus liberibacter solanacearum and Bactericera cockerelli haplotypes in zebra chip incidence and symptom severity
American Journal of Potato Research, 2018Co-Authors: Kylie Swisher D Grimm, Rodney W Cooper, Tariq Mustafa, Joseph E. MunyanezaAbstract:Two haplotypes of the pathogen, ‘Candidatus Liberibacter solanacearum,’ (Lso) and four haplotypes of the insect vector, Bactericera cockerelli, are associated with zebra chip disease of potato. Whether disease severity or incidence is influenced by pathogen or insect haplotype is poorly understood. The role of Lso ‘A’ and ‘B,’ transmitted by three haplotypes of B. cockerelli, on disease severity and incidence in eight potato cultivars was analyzed. Both haplotypes of Lso induced tuber symptoms. In general, Lso B caused higher incidence of symptoms, and greater reduction in tubers compared with Lso A. Lso B was associated with more severe tuber symptoms, producing fewer mild or moderate tuber symptoms. Lso A was associated with less severe tuber symptoms, despite being able to induce severe symptoms. Disease incidence, tuber yield, and symptom severity ratings were not dependent upon the psyllid haplotype transmitting the pathogen, suggesting that pathogen, not insect haplotype affects Lso transmission.
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Wolbachia Infection Differs Among Divergent Mitochondrial Haplotypes of Bactericera cockerelli (Hemiptera: Triozidae)
Annals of the Entomological Society of America, 2015Co-Authors: W. Rodney Cooper, Kylie D. Swisher, Joseph E. Munyaneza, Stephen F. Garczynski, Tariq Mustafa, David R. HortonAbstract:ABSTRACT Four mitochondrial (cytrochrome oxidase I) haplotypes of the potato psyllid, Bactericera cockerelli (Sulc) (Hemiptera: Triozidae), have been identified in North America: western, central, northwestern, and southwestern. A recent study found that females of the northwestern haplotype mated by males of the western or central haplotypes failed to produce viable eggs. Our goal was to determine whether these patterns in reproductive incompatibility are associated with differences among haplotypes in the presence of cytoplasmic incompatibility-inducing bacteria, Wolbachia or Cardinium. Polymerase chain reaction (PCR) revealed that psyllids of the western and central haplotypes were both simultaneously infected with two strains of Wolbachia, but Wolbachia was not detected in psyllids of the northwestern haplotype. PCR using archived DNA from field-collected psyllids confirmed patterns in Wolbachia infection among the western, central, and northwestern haplotypes, and also indicated that Wolbachia was no...
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Characterization and Correlation of EPG Waveforms of Bactericera cockerelli (Hemiptera: Triozidae): Variability in Waveform Appearance in Relation to Applied Signal
Annals of the Entomological Society of America, 2014Co-Authors: Cole C. Pearson, Elaine A. Backus, Holly J. Shugart, Joseph E. MunyanezaAbstract:ABSTRACT The tomato-potato psyllid, Bactericera cockerelli (Sulc) (Hemiptera: Triozidae), was recently shown to be a vector of “Candidatus Liberibacter solanacearum” (Lso), a phloem-limited bacterium that is the putative causal agent of “zebra chip” in potato and unnamed diseases in other solanaceous species. Despite its importance, very little is known about B. cockerelli stylet probing behaviors that control transmission of Lso to its host plants. Herein, we report the first study characterizing the electrical penetration graph waveforms representing stylet penetration behaviors of the B. cockerelli feeding on potato. Waveforms produced by adult B. cockerelli on potato were also correlated using light microscopy of salivary sheath termini in plant tissue after probes were artificially terminated during the identified waveforms. In addition, behavioral activities were inferred based on electrical origins of waveforms as well as similarities in waveform appearances with those of other psyllids, aphids, an...
John T Trumble - One of the best experts on this subject based on the ideXlab platform.
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Factors influencing host plant choice and larval performance in Bactericera cockerelli.
PloS one, 2014Co-Authors: Sean M. Prager, Isaac Esquivel, John T TrumbleAbstract:Among the many topics of interest to ecologists studying associations between phytophagous insects and their host plants are the influence of natal host plant on future oviposition decisions and the mechanisms of generalist versus specialist host selection behavior. In this study, we examined the oviposition preferences, behavior and larval development of the tomato/potato psyllid, Bactericera cockerelli. By rearing psyllids with two distinct geographically-linked haplotypes on different host plants, we were able to examine the role of natal host plant and potential local adaptation on host plant usage. Choice bioassays among three host species demonstrated that psyllids from California had clear preferences that were influenced by natal plant. We further found that patterns in choice bioassays corresponded to observed feeding and movement responses. No-choice bioassays demonstrated that there is little to no association between development and host-plant choice for oviposition, while also indicating that host choice varies between haplotypes. These findings support the concept that mothers do not always choose oviposition sites optimally and also add support for the controversial Hopkins' host selection principle.
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a binomial sequential sampling plan for Bactericera cockerelli hemiptera triozidae in solanum lycopersicum solanales solanacea
Journal of Economic Entomology, 2014Co-Authors: Sean M. Prager, Casey D. Butler, John T TrumbleAbstract:ABSTRACT The tomato—potato psyllid Bactericera cockerelli (Sulc) (Hemiptera: Triozidae) is a pest of many solanaceous plants, including tomato (Solanum lycopersicum L.) and potato (Solanum tuberosum L.). In tomato, feeding by nymphs is associated with “psyllid yellows.” B. cockerelli also vectors “Candidatus Liberibacter psyllaurous,” an infectious bacterium that causes “vein greening” disease. Decisions about management action are much more effective when guided by robust sampling. However, there are few previous studies of potato psyllid spatial distribution in tomato fields, and no published sequential sampling plans for the pest in tomato. We studied B. cockerelli in various tomato fields in California and used these data to generate a sequential sampling plan. We found that juvenile B. cockerelli in tomato fields exhibit an edge effect, an aggregated distribution, and individuals are primarily located on the bottom of leaves. Psyllids were concentrated in the upper segments of plants, but this change...
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A Global Comparison of Bactericera cockerelli (Hemiptera: Triozidae) Microbial Communities
Environmental entomology, 2014Co-Authors: Alex P. Arp, James M. Crosslin, John T Trumble, Joseph E. Munyaneza, Blake BextineAbstract:The potato psyllid (Bactericera cockerelli Sulc) is an economically important insect pest of solanaceous crops such as potato, tomato, pepper, and tobacco. Historically, the potato psyllid's range included central United States, Mexico, and California; more recently, populations of this insect have been reported in Central America, the Pacific Northwest, and New Zealand. Like most phytophagous insects, potato psyllids require symbiotic bacteria to compensate for nutritional deficiencies in their diet. Potato psyllids harbor the primary symbiont, Candidatus Carsonella ruddii, and may also harbor many secondary symbionts such as Wolbachia sp., Sodalis sp., Pseudomonas sp., and others. These secondary symbionts can have an effect on reproduction, nutrition, immune response, and resistances to heat or pesticides. To identify regional differences in potato psyllid bacterial symbionts, 454 pyrosequencing was performed using generic 16S rRNA gene primers. Analysis was performed using the Qiime 1.6.0 software suite, ARB Silva, and R. Operational taxonomic units were then grouped at 97% identity. Representative sequences were classified to genus using the ARB SILVA database. Potato psyllids collected in California contained a less diverse microbial community than those collected in the central United States and Central America. The crop variety, collection year, and haplotype did not seem to affect the microbial community in potato psyllids. The primary difference between psyllids in different regions was the presence and overall bacterial community composition of Candidatus Carsonella ruddii and Wolbachia.
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Considerations for the use of neonicotinoid pesticides in management of Bactericera cockerelli (Šulk) (Hemiptera: Triozidae)
Crop Protection, 2013Co-Authors: Sean M. Prager, Frank J. Byrne, Beatriz G. Vindiola, Gregory S Kund, John T TrumbleAbstract:Abstract Bactericera cockerelli is a pest on multiple solanaceous crop plants and is the sole vector for the bacteria Candidatus Liberibacter psyllaurous. When the pathogen is present, feeding by these psyllids results in ‘vein greening’ disease in peppers and tomatoes, and “zebra chip” disease in potatoes. Currently, management is based entirely on the application of pesticides, including two neonicotinoid compounds. Populations of B. cockerelli collected in southern Texas in 2006 and 2012 were examined for reduced susceptibility and behavioral responses to imidacloprid. Tests comparing imidacloprid and thiamethoxam demonstrated that both can reduce nymph numbers in the field, but retention and effective periods vary among application methods and compounds. In addition, imidacloprid and thiamethoxam are both sensitive to the amount of water applied during irrigation. Collectedly, these results suggest that imidacloprid is unlikely to be effective in controlling B. cockerelli in south Texas. Moreover, its use needs to be carefully considered in other locations even where resistance has not yet been detected. Finally, thiamethoxam may be useful, but careful attention must be paid to irrigation and rainfall level, application method, and timing of application.
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Identification and Impact of Natural Enemies of Bactericera cockerelli (Hemiptera: Triozidae) in Southern California
Journal of economic entomology, 2012Co-Authors: Casey D. Butler, John T TrumbleAbstract:ABSTRACT Bactericera cockerelli (Sulc) (Hemiptera: Triozidae) is a major pest of potato, (Solanum tuberosum L.), tomato (Solanum lycopersicum L.), and peppers (Capsicum spp.). The purpose of our research was to identify and determine the impact of natural enemies on B. cockerelli population dynamics. Through 2 yr of field studies (2009–2010) at four different sites and laboratory feeding tests, we identified minute pirate bug, Orius tristicolor (White) (Hemiptera: Anthocoridae); western bigeyed bug, Geocoris pallens Stal (Hemiptera: Geocoridae), and convergent lady beetle, Hippodamia convergent Guerin-Meneville (Coleoptera: Coccinellidae) as key natural enemies of B. cockerelli in southern California potatoes, tomatoes, and bell peppers. In natural enemy exclusion cage experiments in the potato crop and in American nightshade, Solanum americanum Miller, the number of B. cockerelli surviving was significantly greater in the closed cage treatments, thus confirming the affect natural enemies can have on B. c...
Freddy Ibanez - One of the best experts on this subject based on the ideXlab platform.
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Bactericera cockerelli vitellogenin-6 like, a vitellogenin without a direct reproductive function?
Insect molecular biology, 2017Co-Authors: Freddy Ibanez, Xiao-tian Tang, Cecilia TamborindeguyAbstract:Vitellogenin-like proteins are members of the large lipid transfer proteins, a family of proteins involved in reproduction, lipid circulation and immune defences. In this study, we identified a new Bactericera cockerelli vitellogenin-like (Vg-like) transcript, and named it BcVg6-like based on its similarity to Acyrthosiphon pisum Vg6. In silico analyses predicted different conserved domains in BcVg6-like compared with the conventional Ba. cockerelli vitellogenin, BcVg1-like, previously described by our research group. Phylogenetic analyses determined that BcVg6-like clustered with Vg-like-B proteins and not the conventional vitellogenins involved in vitellogenesis. Also, the expression analyses showed differences in BcVg6-like transcript expression between 7-day-old males and 3- and 7-day-old females. BcVg6-like was not upregulated after exogenous application of juvenile hormone III, but its relative expression increased significantly in alimentary canals of adult females exposed to tomato plants infected by the bacterial plant pathogen 'Candidatus Liberibacter solanacearum'. Our results suggest that in Ba. cockerelli, both vitellogenin genes may have different functions: BcVg1-like is a conventional vitellogenin that conserved its ancestral function as an egg yolk precursor whereas BcVg6-like might have acquired a function in lipid and/or other molecule transport, and could potentially play a role in immune defence.
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Identification and expression analyses of vitellogenin in Bactericera cockerelli (Šulc).
Journal of insect physiology, 2016Co-Authors: Freddy Ibanez, Julien Levy, Cecilia TamborindeguyAbstract:Abstract The potato psyllid, Bactericera cockerelli (Sulc) (Hemiptera: Triozidae), is a phloem-feeding insect with preference for Solanaceae. This insect species is vector of the pathogenic bacteria ‘Candidatus Liberibacter solanacearum’ the causative agent of zebra chip, an important disease of commercial potatoes in several countries worldwide. The recent classification of psyllids among the most dangerous vectors has promoted their study, but still many biological processes such as reproduction and vitellogenesis need to be investigated. As a first step towards the elucidation of vitellogenesis in B. cockerelli, one candidate vitellogenin transcript (6622 bases long) was identified and the expression of the transcript and the protein were analyzed in virgin and mated females between 1 and 7 days old. In virgin females, Vg expression increased up to 5 days old; while mating significantly up-regulated Vg expression in 5- and 7-day-old females. To determine the role of juvenile hormone in B. cockerelli Vg expression, topical applications of juvenile hormone III were performed on virgin females, resulting in an up-regulation of Vg expression and an increase in the number of mature oocytes present in female reproductive organs. Overall, this study represents the first step to understand vitellogenesis of B. cockerelli and it highlights the role of JH III in the hormonal regulation of Vg expression and oocyte development.
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Interactions "Candidatus Liberibacter solanacearum"-Bactericera cockerelli: Haplotype Effect on Vector Fitness and Gene Expression Analyses.
Frontiers in cellular and infection microbiology, 2016Co-Authors: Jianxiu Yao, Freddy Ibanez, Julien Levy, Ordom Brian Huot, Panatda Saenkham, Christophe Noroy, Azucena Mendoza, Damien F. Meyer, Cecilia TamborindeguyAbstract:‘Candidatus Liberibacter solanacearum’ (Lso) has emerged as a serious threat world-wide. Five Lso haplotypes have been identified so far. Haplotypes A and B are present in the Americas and/or New Zealand, where they are vectored to solanaceous plants by the potato psyllid, Bactericera cockerelli (Sulc) (Hemiptera: Triozidae). The fastidious nature of these pathogens has hindered the study of the interactions with their eukaryotic hosts (vector and plant). To understand the strategies used by these pathogens to infect their vector, the effects of each Lso haplotype (A or B) on psyllid fitness was investigated, and genome-wide transcriptomic and RT-qPCR analyses were performed to evaluate Lso gene expression in association with its vector. Results showed that psyllids infected with haplotype B had significantly lower percentage of nymphal survival compared to psyllids infected with haplotype A. Although overall gene expression across Lso genome was similar between the two Lso haplotypes, differences in the expression of key candidate genes were found. Among the 16 putative type IV effector genes tested, four of them were differentially expressed between Lso haplotypes, while no differences in gene expression were measured by qPCR or transcriptomic analysis for the rest of the genes. This study provides new information regarding the pathogenesis of Lso haplotypes in their insect vector.
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Selection of reference genes for expression analysis in the potato psyllid, Bactericera cockerelli
Insect molecular biology, 2016Co-Authors: Freddy Ibanez, Cecilia TamborindeguyAbstract:The selection of reference genes is a crucial step for quantitative real-time PCR analyses and increasingly the use of more than one reference gene for accurate and reliable normalization is being recommended. In this study, a set of six genes was selected and their stability was assessed in different life stages and female organs of Bactericera cockerelli harbouring or not the bacterial pathogen 'Candidatus Liberibacter solanacearum' (Lso) haplotype B. The stability of each gene was determined using the BestKeeper, NormFinder and GeNorm programs. These analyses identified elongation factor-1a, ribosomal protein subunit L5 and ribosomal protein subunit 18 as the most stable genes to analyse gene expression during the insect life stages irrespective of Lso presence; Lso haplotype B only affected their respective ranking. By contrast, a common set of normalizers could not be found amongst the different female organs tested (bacteriomes, alimentary canals and reproductive organs).
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Interactions “Candidatus Liberibacter solanacearum”—Bactericera cockerelli: haplotype effect on vector fitness and gene expression analyses
Frontiers in Cellular and Infection Microbiology, 2016Co-Authors: Jianxiu Yao, Freddy Ibanez, Julien Levy, Panatda Saenkham, Christophe Noroy, Azucena Mendoza, Ordom Huot, Damien Meyer, Cecilia TamborindeguyAbstract:Candidatus Liberibacter solanacearum" (Lso) has emerged as a serious threat world-wide. Five Lso haplotypes have been identified so far. Haplotypes A and B are present in the Americas and/or New Zealand, where they are vectored to solanaceous plants by the potato psyllid, Bactericera cockerelli (Sulc) (Hemiptera: Triozidae). The fastidious nature of these pathogens has hindered the study of the interactions with their eukaryotic hosts (vector and plant). To understand the strategies used by these pathogens to infect their vector, the effects of each Lso haplotype (A or B) on psyllid fitness was investigated, and genome-wide transcriptomic and RT-qPCR analyses were performed to evaluate Lso gene expression in association with its vector. Results showed that psyllids infected with haplotype B had significantly lower percentage of nymphal survival compared to psyllids infected with haplotype A. Although overall gene expression across Lso genome was similar between the two Lso haplotypes, differences in the expression of key candidate genes were found. Among the 16 putative type IV effector genes tested, four of them were differentially expressed between Lso haplotypes, while no differences in gene expression were measured by qPCR or transcriptomic analysis for the rest of the genes. This study provides new information regarding the pathogenesis of Lso haplotypes in their insect vector.
Julien Levy - One of the best experts on this subject based on the ideXlab platform.
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Identification and expression analyses of vitellogenin in Bactericera cockerelli (Šulc).
Journal of insect physiology, 2016Co-Authors: Freddy Ibanez, Julien Levy, Cecilia TamborindeguyAbstract:Abstract The potato psyllid, Bactericera cockerelli (Sulc) (Hemiptera: Triozidae), is a phloem-feeding insect with preference for Solanaceae. This insect species is vector of the pathogenic bacteria ‘Candidatus Liberibacter solanacearum’ the causative agent of zebra chip, an important disease of commercial potatoes in several countries worldwide. The recent classification of psyllids among the most dangerous vectors has promoted their study, but still many biological processes such as reproduction and vitellogenesis need to be investigated. As a first step towards the elucidation of vitellogenesis in B. cockerelli, one candidate vitellogenin transcript (6622 bases long) was identified and the expression of the transcript and the protein were analyzed in virgin and mated females between 1 and 7 days old. In virgin females, Vg expression increased up to 5 days old; while mating significantly up-regulated Vg expression in 5- and 7-day-old females. To determine the role of juvenile hormone in B. cockerelli Vg expression, topical applications of juvenile hormone III were performed on virgin females, resulting in an up-regulation of Vg expression and an increase in the number of mature oocytes present in female reproductive organs. Overall, this study represents the first step to understand vitellogenesis of B. cockerelli and it highlights the role of JH III in the hormonal regulation of Vg expression and oocyte development.
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Interactions "Candidatus Liberibacter solanacearum"-Bactericera cockerelli: Haplotype Effect on Vector Fitness and Gene Expression Analyses.
Frontiers in cellular and infection microbiology, 2016Co-Authors: Jianxiu Yao, Freddy Ibanez, Julien Levy, Ordom Brian Huot, Panatda Saenkham, Christophe Noroy, Azucena Mendoza, Damien F. Meyer, Cecilia TamborindeguyAbstract:‘Candidatus Liberibacter solanacearum’ (Lso) has emerged as a serious threat world-wide. Five Lso haplotypes have been identified so far. Haplotypes A and B are present in the Americas and/or New Zealand, where they are vectored to solanaceous plants by the potato psyllid, Bactericera cockerelli (Sulc) (Hemiptera: Triozidae). The fastidious nature of these pathogens has hindered the study of the interactions with their eukaryotic hosts (vector and plant). To understand the strategies used by these pathogens to infect their vector, the effects of each Lso haplotype (A or B) on psyllid fitness was investigated, and genome-wide transcriptomic and RT-qPCR analyses were performed to evaluate Lso gene expression in association with its vector. Results showed that psyllids infected with haplotype B had significantly lower percentage of nymphal survival compared to psyllids infected with haplotype A. Although overall gene expression across Lso genome was similar between the two Lso haplotypes, differences in the expression of key candidate genes were found. Among the 16 putative type IV effector genes tested, four of them were differentially expressed between Lso haplotypes, while no differences in gene expression were measured by qPCR or transcriptomic analysis for the rest of the genes. This study provides new information regarding the pathogenesis of Lso haplotypes in their insect vector.
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Interactions “Candidatus Liberibacter solanacearum”—Bactericera cockerelli: haplotype effect on vector fitness and gene expression analyses
Frontiers in Cellular and Infection Microbiology, 2016Co-Authors: Jianxiu Yao, Freddy Ibanez, Julien Levy, Panatda Saenkham, Christophe Noroy, Azucena Mendoza, Ordom Huot, Damien Meyer, Cecilia TamborindeguyAbstract:Candidatus Liberibacter solanacearum" (Lso) has emerged as a serious threat world-wide. Five Lso haplotypes have been identified so far. Haplotypes A and B are present in the Americas and/or New Zealand, where they are vectored to solanaceous plants by the potato psyllid, Bactericera cockerelli (Sulc) (Hemiptera: Triozidae). The fastidious nature of these pathogens has hindered the study of the interactions with their eukaryotic hosts (vector and plant). To understand the strategies used by these pathogens to infect their vector, the effects of each Lso haplotype (A or B) on psyllid fitness was investigated, and genome-wide transcriptomic and RT-qPCR analyses were performed to evaluate Lso gene expression in association with its vector. Results showed that psyllids infected with haplotype B had significantly lower percentage of nymphal survival compared to psyllids infected with haplotype A. Although overall gene expression across Lso genome was similar between the two Lso haplotypes, differences in the expression of key candidate genes were found. Among the 16 putative type IV effector genes tested, four of them were differentially expressed between Lso haplotypes, while no differences in gene expression were measured by qPCR or transcriptomic analysis for the rest of the genes. This study provides new information regarding the pathogenesis of Lso haplotypes in their insect vector.
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Transcriptome analysis of "Candidatus Liberibacter solanacearum" in its psyllid vector, Bactericera cockerelli.
PloS one, 2014Co-Authors: Freddy Ibanez, Julien Levy, Cecilia TamborindeguyAbstract:“Candidatus Liberibacter solanacearum” (Lso) is an emergent pathogen of carrots in Europe and solanaceous plants in North and Central America and New Zealand. This bacterium is closely related to other pathogenic Candidatus Liberibacter spp., all vectored by psyllids. In order to understand the molecular interaction of this pathogen and its psyllid vector, Bactericera cockerelli, Illumina sequencing of psyllid harboring Lso was performed to determine if this approach could be used to assess the bacterial transcriptome in this association. Prior to sequencing, psyllid RNA was purified and insect and bacterial rRNA were removed. Mapping of reads to Lso genome revealed that over 92% of the bacterial genes were expressed in the vector, and that the COG categories Translation and Post-translational modification, protein turnover, chaperone functions were the most expressed functional categories. Expression levels of selected Lso genes were confirmed by RT-qPCR. The transcriptomic analysis also helped correct Lso genome annotation by identifying the expression of genes that were not predicted in the genome sequencing effort.
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Solanum habrochaites, a potential source of resistance against Bactericera cockerelli (Hemiptera: Triozidae) and "Candidatus Liberibacter solanacearum".
Journal of economic entomology, 2014Co-Authors: Julien Levy, Cecilia TamborindeguyAbstract:ABSTRACT The potato psyllid, Bactericera cockerelli Sulc, also known as tomato psyllid, is a serious pest of solanaceous plants. Its host selection criteria are poorly understood. In this study, we tested whether the Solanum habrochaites (PI127826), a wild solanaceous plant known for its property to repel whiteflies, was repellent to potato psyllids. Using a combination of nonchoice assays and choice assays on different psyllid stages, we demonstrated that S. habrochaites is both repelling and toxic to potato psyllids compared with Solanum lycopersicum. However, those properties were not sufficient to avoid transmission of the plant bacterial pathogen “Candidatus Liberibacter solanacearum” vectored by potato psyllids, the causative agent of potato zebra chip disease. However, a lower bacterial transmission rate to S. habrochaites was observed compared with S. lycopersicum.
