Publications

TitleAbstractYear
Filter
PMID
Filter
functional characterization of lotp from liberibacter asiaticus.liberibacter asiaticus is an unculturable parasitic bacterium of the alphaproteobacteria group hosted by both citrus plants and a psyllid insect vector (diaphorina citri). in the citrus tree, the bacteria thrive only inside the phloem, causing a systemically incurable and deadly plant disease named citrus greening or huanglongbing. currently, all commercial citrus cultivars in production are susceptible to l. asiaticus, representing a serious threat to the citrus industry worldwide. the technica ...201728378385
new excised-leaf assay method to test inoculativity of asian citrus psyllid (hemiptera: psyllidae) with candidatus liberibacter asiaticus associated with citrus huanglongbing disease.the asian citrus psyllid, diaphorina citri kuwayama (hemiptera: psyllidae), is the primary vector of candidatus liberibacter asiaticus (las) associated with huanglongbing, or citrus greening, the most devastating citrus (citrus spp.) disease worldwide. here, we developed a new "excised-leaf assay" that can speed up las-inoculativity tests on asian citrus psyllid from the current 3-12 mo (when using whole citrus seedlings for inoculation) to only 2-3 wk. young adults of asian citrus psyllid that ...201323448011
costs and benefits of insecticide and foliar nutrient applications to huanglongbing-infected citrus trees.the asian citrus psyllid (acp), diaphorina citri kuwayama (hemiptera: psyllidae), vectors candidatus liberibacter asiaticus, which causes huanglongbing (hlb). in florida, hlb incidence is approaching 100% statewide. yields have decreased and production costs have increased since 2005. despite this, some growers are maintaining a level of production and attribute this in part to aggressive psyllid control and foliar nutrition sprays. however, the value of these practices is debated. a replicated ...201727427170
enhanced acquisition rates of 'candidatus liberibacter asiaticus' by the asian citrus psyllid (hemiptera: liviidae) in the presence of vegetative flush growth in citrus.the asian citrus psyllid preferentially feeds and exclusively reproduces on young, newly emerged flush shoots of citrus. asian citrus psyllid nymphs feed and complete their life stages on these flush shoots. recent studies conducted under greenhouse conditions have shown that the transmission rates of 'candidatus liberibacter asiaticus' (clas), the putative causal agent of huanglongbing disease of citrus, are enhanced when flush shoots are present. however, it is unclear if clas acquisition by m ...201627451998
nucleotides, micro- and macro-nutrients, limonoids, flavonoids, and hydroxycinnamates composition in the phloem sap of sweet orange.currently, the global citrus production is declining due to the spread of huanglongbing (hlb). hlb, otherwise known as citrus greening, is caused by candidatus liberibacter asiaticus (clas) and is transmitted by the asian citrus psyllids (acp), diaphorina citri kuwayama. acp transmits clas bacterium while feeding on the citrus phloem sap. multiplication of clas in the phloem of citrus indicates that the sap contains all the essential nutrients needed for clas. in this study, we investigated the ...201627171979
metabolomic comparative analysis of the phloem sap of curry leaf tree (bergera koenegii), orange jasmine (murraya paniculata), and valencia sweet orange (citrus sinensis) supports their differential responses to huanglongbing.orange jasmine, murraya paniculata and curry leaf tree, bergera koenegii are alternative hosts for diaphorina citri, the vector of candidatus liberibacter asiaticus (clas), the pathogen of huanglongbing (hlb) in citrus. d. citri feeds on the phloem sap where clas grows. it has been shown that orange jasmine was a better host than curry leaf tree to d. citri. in addition, clas can infect orange jasmine but not curry leaf tree. here, we compared the phloem sap composition of these 2 plants to the ...201627763819
phenology of asian citrus psyllid (hemiptera: liviidae) and associated parasitoids on two species of citrus, kinnow mandarin and sweet orange, in punjab pakistan.the population phenology of asian citrus psyllid, diaphorina citri kuwayama, was monitored weekly for 110 wk on two species of citrus, kinnow mandarin and sweet orange, at two different research sites in faisalabad, punjab pakistan. citrus flush growth patterns were monitored and natural enemy surveys were conducted weekly. flush patterns were similar for kinnow and sweet orange. however, flush on sweet orange was consistently more heavily infested with asian citrus psyllid than kinnow flush; de ...201425198345
acquisition, replication and inoculation of candidatus liberibacter asiaticus following various acquisition periods on huanglongbing-infected citrus by nymphs and adults of the asian citrus psyllid.the asian citrus psyllid, diaphorina citri (hemiptera: liviidae), is the primary vector of candidatus liberibacter asiaticus (las) implicated as causative agent of citrus huanglongbing (citrus greening), currently the most serious citrus disease worldwide. las is transmitted by d. citri in a persistent-circulative manner, but the question of replication of this bacterium in its psyllid vector has not been resolved. thus, we studied the effects of the acquisition access period (aap) by nymphs and ...201627441694
incidence of candidatus liberibacter asiaticus infection in abandoned citrus occurring in proximity to commercially managed groves.huanglongbing is one of the most devastating diseases of citrus (citrus spp.). one management tactic against huanglongbing is aggressive management of the vector, the asian citrus psyllid (diaphorina citri kuwayama), with insecticide applications. however, d. citri in abandoned groves are not controlled and therefore pose a risk of reinfestation for nearby commercial citrus. these abandoned groves could serve as a reservoir for the vector, as well as a source of the presumed causal agent for hua ...201021309215
asian citrus psyllid expression profiles suggest candidatus liberibacter asiaticus-mediated alteration of adult nutrition and metabolism, and of nymphal development and immunity.the asian citrus psyllid (acp) diaphorina citri kuwayama (hemiptera: psyllidae) is the insect vector of the fastidious bacterium candidatus liberibacter asiaticus (clas), the causal agent of citrus greening disease, or huanglongbing (hlb). the widespread invasiveness of the psyllid vector and hlb in citrus trees worldwide has underscored the need for non-traditional approaches to manage the disease. one tenable solution is through the deployment of rna interference technology to silence protein- ...201526091106
sulfur volatiles from allium spp. affect asian citrus psyllid, diaphorina citri kuwayama (hemiptera: psyllidae), response to citrus volatiles.the asian citrus psyllid, diaphorina citri kuwayama, vectors candidatus liberibacter asiaticus (las) and candidatus liberibacter americanus (lam), the presumed causal agents of huanglongbing. d. citri generally rely on olfaction and vision for detection of host cues. plant volatiles from allium spp. (alliaceae) are known to repel several arthropod species. we examined the effect of garlic chive (a. tuberosum rottl.) and wild onion (a. canadense l.) volatiles on d. citri behaviour in a two-port d ...201120609277
rate, placement and timing of aldicarb applications to control asian citrus psyllid, diaphorina citri kuwayama (hemiptera: psyllidae), in oranges.the asian citrus psyllid (acp), diaphorina citri kuwayama (hemiptera: psyllidae), is a cosmopolitan insect pest of citrus and vectors the bacterium candidatus liberibacter asiaticus, a suspected causal organism of citrus greening or 'huanglongbing' disease. aldicarb 150 g kg(-1) gr (temik((r)) 15 g) was evaluated at three rates, two placements and three timings for acp control in orange trees.200818537108
citrus huanglongbing in são paulo state, brazil: pcr detection of the 'candidatus' liberibacter species associated with the disease.symptoms of huanglongbing (hlb), one of the most serious diseases of citrus in asia and africa, have been noticed in march 2004 in the araraquara region of são paulo state, brazil. hlb has not been reported previously from america. the causal hlb bacteria, candidatus liberibacter africanus in africa and candidatus liberibacter asiaticus in asia, can be detected in symptomatic citrus leaves by pcr amplification of their 16s rdna with previously described primers. when this technique was applied t ...200515797817
incidence of invasive diaphorina citri (hemiptera: psyllidae) and its introduced parasitoid tamarixia radiata (hymenoptera: eulophidae) in florida citrus.diaphorina citri kuwayama (hemiptera: psyllidae), vectors the bacterium candidatus liberibacter asiaticus, one of the causal organisms of the devastating citrus disease "huanglongbing" or citrus greening. in the united states, d. citri was first discovered in florida, in 1998. tamarixia radiata waterston (hymenoptera: eulophidae) was imported from asia and released in florida in 1999-2001 to improve biological control of d. citri before citrus greening was detected in florida in 2005. florida ci ...200919253643
establishment of asian citrus psyllid (diaphorina citri) primary cultures.the asian citrus psyllid (ascp), diaphorina citri kuwayama (hemiptera: psyllidae), is a highly competent vector of the phloem-inhabiting bacterium candidatus liberibacter asiaticus associated with the citrus disease huanglongbing (hlb). commonly referred to as citrus greening disease in the usa, hlb causes reduced fruit yields, quality, and ultimately tree death and is considered the most serious citrus disease. hlb has become a major limiting factor to the production of citrus worldwide. studie ...200919440802
effect of sucrose octanoate on survival of nymphal and adult diaphorina citri (homoptera: psyllidae).asian citrus psylla, diaphorina citri kuwayama (homoptera: psyllidae) was detected for the first time in the united states near delray beach, fl, on 2 june 1998 and is continuing to spread and multiply throughout southern florida. this psyllid is the vector of liberobacter asiaticum, a phloem-limited bacterium that causes citrus greening disease. this pathogen has not been found in the western hemisphere to date. furthermore, high infestation levels of d. citri can impact citrus plant health, fr ...200415279280
inter-population variability of endosymbiont densities in the asian citrus psyllid (diaphorina citri kuwayama).the asian citrus psyllid (diaphorina citri kuwayama) is an insect pest capable of transmitting candidatus liberibacter asiaticus (clas), the causal agent of citrus greening in north america. d. citri also harbors three endosymbionts, wolbachia, candidatus carsonella ruddii, and candidatus profftella armatura, which may influence d. citri physiology and fitness. although genomic researches on these bacteria have been conducted, much remains unclear regarding their ecology and inter-population var ...201626846216
characterization of a recombinant cathepsin b-like cysteine peptidase from diaphorina citri kuwayama (hemiptera: liviidae): a putative target for control of citrus huanglongbing.huanglonbing (hlb) is one of the most destructive disease affecting citrus plants. the causal agent is associated with the phloem-limited bacterium candidatus liberibacter asiaticus (clas) and the psyllid diaphorina citri, vector of disease, that transmits the bacterium associated with hlb. the control of disease can be achieved by suppressing either the bacterium or the vector. among the control strategies for hlb disease, one of the widely used consists in controlling the enzymes of the diseas ...201526717484
draft genome sequence of "candidatus liberibacter asiaticus" from diaphorina citri in guangdong, china.the draft genome sequence of "candidatus liberibacter asiaticus" strain ycpsy from an asian citrus psyllid (diaphorina citri) in guangdong, china, is reported here. the ycpsy strain has a genome size of 1,233,647 bp, 36.5% g+c content, 1,171 open reading frames (orfs), and 53 rnas.201526543132
characterization of the voltage-gated sodium channel of the asian citrus psyllid, diaphorina citri.the asian citrus psyllid, diaphorina citri kuwayama (hemiptera: liviidae), is an important insect pest of citrus. it is the vector of 'candidatus' liberibacter asiaticus, a phloem-limited bacterium that infects citrus, resulting in the disease huanglongbing (hlb). disease management relies heavily on suppression of d. citri populations with insecticides, including pyrethroids. in recent annual surveys to monitor insecticide resistance, reduced susceptibility to fenpropathrin was identified in se ...201726537022
better together: association with 'candidatus liberibacter asiaticus' increases the reproductive fitness of its insect vector, diaphorina citri (hemiptera: liviidae).the duration of the evolutionary association between a pathogen and vector can be inferred based on the strength of their mutualistic interactions. a well-adapted pathogen is likely to confer some benefit or, at a minimum, exhibit low pathogenicity toward its host vector. coevolution of the two toward a mutually beneficial association appears to have occurred between the citrus greening disease pathogen, candidatus liberibacter asiaticus (las), and its insect vector, the asian citrus psyllid, di ...201627418697
comparative proteomic analysis of hemolymph from uninfected and candidatus liberibacter asiaticus-infected diaphorina citri.hemolymph was characterized from diaphorina citri adults infected with the phytopathogen, candidatus liberibacter asiaticus (clas), and compared with that from uninfected psyllids. this study identified 5531 and 3220 peptides within infected and uninfected hemolymph using nano-lc-ms/ms. a reduced number of proteins were detected for d. citri and all known endosymbionts within infected hemolymph as compared to uninfected hemolymph. a large number of immune defense proteins were absent from d. cit ...201727990558
disruption of vector host preference with plant volatiles may reduce spread of insect-transmitted plant pathogens.plant pathogens can manipulate the odor of their host; the odor of an infected plant is often attractive to the plant pathogen vector. it has been suggested that this odor-mediated manipulation attracts vectors and may contribute to spread of disease; however, this requires further broad demonstration among vector-pathogen systems. in addition, disruption of this indirect chemical communication between the pathogen and the vector has not been attempted. we present a model that demonstrates how a ...201627193763
diaphorina citri (hemiptera: liviidae) vector competence for the citrus greening pathogen 'candidatus liberibacter asiaticus'.characterizing the vector competence of diaphorina citri kuwayama for 'candidatus liberibacter asiaticus,' the pathogen causing citrus greening, is essential for understanding the epidemiology of this disease that is threatening the u.s. citrus industry. vector competence studies have been difficult because of the biology of d. citri, the inability to culture the pathogen, and the available diagnostic methods used to detect the bacteria in plant and insect tissues. the methods employed in many s ...201526470202
effect of cyantraniliprole, a novel insecticide, on the inoculation of candidatus liberibacter asiaticus associated with citrus huanglongbing by the asian citrus psyllid (hemiptera: liviidae).the asian citrus psyllid (diaphorina citri kuwayama) is the principal vector of 'candidatus liberibacter asiaticus' (clas) associated with huanglongbing (hlb), the most serious citrus disease worldwide. new control measures including pesticides are urgently needed to combat hlb, especially to protect young or newly planted citrus trees from clas-inoculation by vector psyllids. here, we tested clas-inoculation by d. citri adults (clas-exposed, reared on infected plants) by feeding them for 7 d on ...201526470150
seasonal movement patterns and long-range dispersal of asian citrus psyllid in florida citrus.the asian citrus psyllid, diaphorina citri kuwayama, is the vector of the bacterial pathogen, candidatus liberibacter asiaticus, which is the causal agent of huanglongbing (hlb) in the united states. both short-range and long-range dispersal of d. citri adults affect the spread of hlb; however, little is known about the long-range dispersal capabilities of d. citri in the field or the seasonality of flight behavior. in the present study, an in situ protein marking technique was used to determine ...201526470097
effects of candidatus liberibacter asiaticus on the fitness of the vector diaphorina citri.the asian citrus psyllid (acp), diaphorina citri kuwayama transmits the bacterium 'candidatus liberibacter asiaticus' (las), which causes citrus huanglongbing (hlb) disease. although many studies have been conducted on the biology of acp on different host plants, few have taken the plant, las bacteria and the vector insect within one context to evaluate the effects of las on the fitness of acp under field conditions. understanding the relationship between las and acp is critical for both acp and ...201627667799
asymptomatic spread of huanglongbing and implications for disease control.huanglongbing (hlb) is a bacterial infection of citrus trees transmitted by the asian citrus psyllid diaphorina citri. mitigation of hlb has focused on spraying of insecticides to reduce the psyllid population and removal of trees when they first show symptoms of the disease. these interventions have been only marginally effective, because symptoms of hlb do not appear on leaves for months to years after initial infection. limited knowledge about disease spread during the asymptomatic phase is e ...201526034273
a plant bacterial pathogen manipulates its insect vector's energy metabolism.insect-transmitted plant-pathogenic bacteria may alter their vectors' fitness, survival, behavior, and metabolism. because these pathogens interact with their vectors on the cellular and organismal levels, potential changes at the biochemical level might occur. "candidatus liberibacter asiaticus" (clas) is transmitted in a persistent, circulative, and propagative manner. the genome of clas revealed the presence of an atp translocase that mediates the uptake of atp and other nucleotides from medi ...201728039132
oral delivery of double-stranded rnas induces mortality in nymphs and adults of the asian citrus psyllid, diaphorina citri.the asian citrus psyllid (acp), diaphorina citri kuwayama, is one of the most important citrus pests. acp is the vector of the phloem-limited bacteria candidatus liberibacter americanus and candidatus liberibacter asiaticus, the causal agents of the devastating citrus disease huanglongbing (hlb). the management of hlb is based on the use of healthy young plants, eradication of infected plants and chemical control of the vector. rna interference (rnai) has proven to be a promising tool to control ...201728282380
sclerenchymatous ring as a barrier to phloem feeding by asian citrus psyllid: evidence from electrical penetration graph and visualization of stylet pathways.asian citrus psyllid (diaphorina citri) feeding behaviors play a significant role in the transmission of the phloem-limited candidatus liberibacter asiaticus (clas) bacterium that causes the economically devastating citrus greening disease. sustained phloem ingestion by d. citri on clas infected plants is required for pathogen acquisition and transmission. recent studies have shown a fibrous ring of thick-walled sclerenchyma around the phloem in mature, fully expanded citrus leaves that is more ...201728278248
the push-pull strategy for citrus psyllid control.the asian citrus psyllid (acp), diaphorina citri kuwayama (hemiptera: psyllidae), is the only natural vector of candidatus liberibacter asiaticus that causes citrus huanglongbing (hlb), a most destructive disease of citrus. currently, no remedial therapy exists for the disease, and so effective control of acp is very important in curbing the transmission of the disease. the push-pull strategy should be thoroughly explored as an approach to acp management. this mini-review summarises the current ...201525256398
nested-quantitative pcr approach with improved sensitivity for the detection of low titer levels of candidatus liberibacter asiaticus in the asian citrus psyllid, diaphorina citri kuwayama.candidatus liberibacter asiaticus (clas) is a phloem-limited bacterium transmitted by the asian citrus psyllid, diaphorina citri, and the presumptive causal agent of citrus greening disease. the current method of detection for clas within plant and insect samples is by a presence/absence qpcr assay using the clas 16s rdna gene target. although qpcr is highly sensitive, low bacterial titers or suboptimal qpcr conditions can result in false-negatives. using a nested qpcr assay, we determined the f ...201424769405
chemical and behavioral analysis of the cuticular hydrocarbons from asian citrus psyllid, diaphorina citri.huanglongbing (hlb) is the most destructive disease of citrus worldwide. the asian citrus psyllid, diaphorina citri kuwayama (hemiptera: psyllidae), is the vector of the phloem-inhabiting bacterium, candidatus liberibacter asiaticus, which is presumed to cause hlb in florida citrus. laboratory and field studies were conducted to examine the behavioral responses of male and female d. citri to their cuticular extracts. in olfactometer assays, more male d. citri were attracted to one, five, or 10 f ...201323955888
herbivory by the insect diaphorina citri induces greater change in citrus plant volatile profile than does infection by the bacterium, candidatus liberibacter asiaticus.the volatile organic compound (voc) profile in plant leaves often changes after biotic and abiotic stresses. monitoring changes in vocs in plant leaves could provide valuable information about multitrophic interactions. in the current study, we investigated the effect of asian citrus psyllid (acp) infestation, citrus greening pathogen (candidatus liberibacter asiaticus [clas]) infection, and simultaneous attack by acp and clas on the voc content of citrus leaves. leaf volatiles were extracted us ...201323857364
rna interference of carboxyesterases causes nymph mortality in the asian citrus psyllid, diaphorina citri.asian citrus psyllid, diaphorina citri kuwayama (hemiptera: liviidae), is an important pest of citrus. in addition, d. citri is the vector of huanglongbing, a destructive disease in citrus, also known as citrus greening disease caused by candidatus liberibacter asiaticus. huanglongbing causes huge losses for citrus industries. insecticide application for d. citri is the major strategy to prevent disease spread. the heavy use of insecticides causes development of insecticide resistance. we used r ...201728195667
silencing abnormal wing disc gene of the asian citrus psyllid, diaphorina citri disrupts adult wing development and increases nymph mortality.huanglongbing (hlb) causes considerable economic losses to citrus industries worldwide. its management depends on controlling of the asian citrus psyllid (acp), the vector of the bacterium, candidatus liberibacter asiaticus (clas), the causal agent of hlb. silencing genes by rna interference (rnai) is a promising tool to explore gene functions as well as control pests. in the current study, abnormal wing disc (awd) gene associated with wing development in insects is used to interfere with the fl ...201323734251
double-stranded rna delivery through soaking mediates silencing of the muscle protein 20 and increases mortality to the asian citrus psyllid, diaphorina citri.asian citrus psyllid, diaphorina citri kuwayama, is the most important economic pest of citrus because it transmits candidatus liberibacter asiaticus (clas), the causal agent of huanglongbing (hlb). silencing genes by rna interference (rnai) is a promising approach for controlling d. citri. rnai-based insect management strategies depend on the selection of suitable target genes.201728195429
candidate gene markers for candidatus liberibacter asiaticus for detecting citrus greening disease.citrus huanglongbing (hlb) also known as citrus greening is one of the most devastating diseases of citrus worldwide. the disease is caused by candidatus liberibacter bacterium, vectored by the psyllid diaphorina citri kuwayama and trioza erytreae del guercio. citrus plants infected by the hlb bacterium may not show visible symptoms sometimes for years following infection. the aim of this study was to develop effective gene-specific primer pairs for polymerase chain reaction based method for qui ...201323660656
stylet morphometrics and citrus leaf vein structure in relation to feeding behavior of the asian citrus psyllid diaphorina citri, vector of citrus huanglongbing bacterium.the asian citrus psyllid (acp), diaphorina citri (hemiptera: psyllidae), is the primary vector of the phloem-limited bacterium candidatus liberibacter asiaticus (las) associated with huanglongbing (hlb, citrus greening), considered the world's most serious disease of citrus. stylet morphometrics of acp nymphs and adults were studied in relation to citrus vein structure and to their putative (histologically verified) feeding sites on valencia orange leaves. acp nymphs preferred to settle and feed ...201323555830
global gene expression changes in candidatus liberibacter asiaticus during the transmission in distinct hosts between plant and insect.huanglongbing (hlb) or citrus greening disease is a destructive disease of citrus worldwide, which is associated with candidatus liberibacter asiaticus. this phloem-limited fastidious pathogen is transmitted by the asian citrus psyllid, diaphorina citri, and appears to be an intracellular pathogen that maintains an intimate association with the psyllid or the plant throughout its life cycle. the molecular basis of the interaction of this pathogen with its hosts is not well understood. we hypothe ...201323336388
biology and management of asian citrus psyllid, vector of the huanglongbing pathogens.the asian citrus psyllid, diaphorina citri kuwayama (hemiptera: psyllidae), is the most important pest of citrus worldwide because it serves as a vector of "candidatus liberibacter" species (alphaproteobacteria) that cause huanglongbing (citrus greening disease). all commercially cultivated citrus is susceptible and varieties tolerant to disease expression are not yet available. onset of disease occurs following a long latent period after inoculation, and thus the pathogen can spread widely prio ...201323317046
morphological abnormalities and cell death in the asian citrus psyllid (diaphorina citri) midgut associated with candidatus liberibacter asiaticus.candidatus liberibacter asiaticus (clas) is a phloem-limited, gram-negative, fastidious bacterium that is associated with the development of citrus greening disease, also known as huanglongbing (hlb). clas is transmitted by the asian citrus psyllid (acp) diaphorina citri, in a circulative manner. two major barriers to transmission within the insect are the midgut and the salivary glands. we performed a thorough microscopic analysis within the insect midgut following exposure to clas-infected cit ...201627630042
survey of endosymbionts in the diaphorina citri metagenome and assembly of a wolbachia wdi draft genome.diaphorina citri (hemiptera: psyllidae), the asian citrus psyllid, is the insect vector of ca. liberibacter asiaticus, the causal agent of citrus greening disease. sequencing of the d. citri metagenome has been initiated to gain better understanding of the biology of this organism and the potential roles of its bacterial endosymbionts. to corroborate candidate endosymbionts previously identified by rdna amplification, raw reads from the d. citri metagenome sequence were mapped to reference genom ...201223166822
annotation of the asian citrus psyllid genome reveals a reduced innate immune system.citrus production worldwide is currently facing significant losses due to citrus greening disease, also known as huanglongbing. the citrus greening bacteria, candidatus liberibacter asiaticus (clas), is a persistent propagative pathogen transmitted by the asian citrus psyllid, diaphorina citri kuwayama (hemiptera: liviidae). hemipterans characterized to date lack a number of insect immune genes, including those associated with the imd pathway targeting gram-negative bacteria. the d. citri draft ...201627965582
effects of soil-applied imidacloprid on asian citrus psyllid (hemiptera: psyllidae) feeding behavior.the asian citrus psyllid, diaphorina citri kuwayama (hemiptera: psyllidae), is one of the most important pests of citrus (citrus spp.) because of its status as a vector of candidatus liberibacter asiaticus (las), the bacterium associated with citrus greening disease. the use of insecticides for vector control is the primary method of managing the spread of this pathogen. imidacloprid is an insecticide commonly applied to the root zone of young citrus trees to provide systemic protection from pes ...201223156142
sexual transmission of a plant pathogenic bacterium, candidatus liberibacter asiaticus, between conspecific insect vectors during mating.candidatus liberibacter asiaticus is a fastidious, phloem-inhabiting, gram-negative bacterium transmitted by asian citrus psyllid, diaphorina citri kuwayama (hemiptera: psyllidae). the bacterium is the presumed causal agent of huanglongbing (hlb), one of the most destructive and economically important diseases of citrus. we investigated whether las is transmitted between infected and uninfected d. citri adults during courtship. our results indicate that las was sexually transmitted from las-infe ...201122216209
Characterization of five CYP4 genes from Asian citrus psyllid and their expression levels in Candidatus Liberibacter asiaticus-infected and uninfected psyllids.Previously, we reported that Candidatus Liberibacter asiaticus (Las)-infected Diaphorina citri are characterized by lower levels of cytochrome P450 monooxygenases than uninfected counterparts. In the present study, we investigated expression levels of family 4 cytochrome P450 (CYP4) genes in Las-infected and uninfected D.citri adults. Five novel CYP4 genes (CYP4C67, CYP4DA1, CYP4C68, CYP4DB1 and CYP4G70) were identified. Four of the five CYP4 genes were expressed at significantly higher levels i ...201121919983
oral delivery of double-stranded rnas and sirnas induces rnai effects in the potato/tomato psyllid, bactericerca cockerelli.the potato/tomato psyllid, bactericerca cockerelli (b. cockerelli), and the asian citrus psyllid, diaphorina citri (d. citri), are very important plant pests, but they are also vectors of phloem-limited bacteria that are associated with two devastating plant diseases. b. cockerelli is the vector of candidatus liberibacter psyllaurous (solanacearum), which is associated with zebra chip disease of potatoes, and d. citri is the vector of ca. liberibacter asiaticus, which is associated with the huan ...201122110747
effects of buprofezin and diflubenzuron on various developmental stages of asian citrus psyllid, diaphorina citri.diaphorina citri populations in florida are developing resistance to commonly used neurotoxic insecticides. alternatives to neurotoxins, such as insect growth regulators, are needed to control this season-long subtropical pest to prevent or delay development of insecticide resistance. in the present investigation, two insect growth regulators (igrs), buprofezin and diflubenzuron, were evaluated against various developmental stages of d. citri.201222653617
characterization of the relative abundance of the citrus pathogen ca. liberibacter asiaticus in the microbiome of its insect vector, diaphorina citri, using high throughput 16s rrna sequencing.the relationship between the causal agent of huanglongbing (hlb), ca. liberibacter asiaticus(las), and the naturally occurring endosymbiotic community of its insect vector, the asian citrus psyllid (acp), diaphorina citri, was studied. variation was observed in the titer of las within an acp population feeding on the same material. the cause of this disparity is unknown, and has implications for las transmission and the spread of hlb. this study utilizes culture independent methods to establish ...201222529882
induced release of a plant-defense volatile 'deceptively' attracts insect vectors to plants infected with a bacterial pathogen.transmission of plant pathogens by insect vectors is a complex biological process involving interactions between the plant, insect, and pathogen. pathogen-induced plant responses can include changes in volatile and nonvolatile secondary metabolites as well as major plant nutrients. experiments were conducted to understand how a plant pathogenic bacterium, candidatus liberibacter asiaticus (las), affects host preference behavior of its psyllid (diaphorina citri kuwayama) vector. d. citri were att ...201222457628
diaphorina citri induces huanglongbing-infected citrus plant volatiles to repel and reduce the performance of propylaea japonica.transmission of plant pathogens through insect vectors is a complex biological process involving interactions between the host plants, insects, and pathogens. simultaneous impact of the insect damage and pathogenic bacteria in infected host plants induce volatiles that modify not only the behavior of its insect vector but also of their natural enemies, such as parasitoid wasps. therefore, it is essential to understand how insects such as the predator ladybird beetle responds to volatiles emitted ...201628083006
infection density dynamics of the citrus greening bacterium "candidatus liberibacter asiaticus" in field populations of the psyllid diaphorina citri and its relevance to the efficiency of pathogen transmission to citrus plants.huanglongbing, or citrus greening, is a devastating disease of citrus plants recently spreading worldwide, which is caused by an uncultivable bacterial pathogen, "candidatus liberibacter asiaticus," and vectored by a phloem-sucking insect, diaphorina citri. we investigated the infection density dynamics of "ca. liberibacter asiaticus" in field populations of d. citri with experiments using field-collected insects to address how "ca. liberibacter asiaticus" infection density in the vector insect ...201525819961
citrus tristeza virus-based rnai in citrus plants induces gene silencing in diaphorina citri, a phloem-sap sucking insect vector of citrus greening disease (huanglongbing).a transient expression vector based on citrus tristeza virus (ctv) is unusually stable. because of its stability it is being considered for use in the field to control huanglongbing (hlb), which is caused by candidatus liberibacter asiaticus (clas) and vectored by asian citrus psyllid, diaphorina citri. in the absence of effective control strategies for clas, emphasis has been on control of d. citri. coincident cohabitation in phloem tissue by clas, d. citri and ctv was exploited to develop a no ...201424572372
transmission parameters for candidatus liberibacter asiaticus by asian citrus psyllid (hemiptera: psyllidae).the purpose of this investigation was to evaluate acquisition and inoculation (together, transmission) efficiency of candidatus liberibacter asiaticus (las), the pathogen associated with citrus huanglongbing (hlb) by the asian citrus psyllid, diaphorina citri (kuwayama) (hemiptera: psyllidae). in laboratory studies, nymphs reared on las infected plants were more likely to acquire the bacterium than adults. acquisition by nymphs ranged from 60 to 100%, whereas acquisition by adults only reached 4 ...201021061950
infection of an insect vector with a bacterial plant pathogen increases its propensity for dispersal.the spread of vector-transmitted pathogens relies on complex interactions between host, vector and pathogen. in sessile plant pathosystems, the spread of a pathogen highly depends on the movement and mobility of the vector. however, questions remain as to whether and how pathogen-induced vector manipulations may affect the spread of a plant pathogen. here we report for the first time that infection with a bacterial plant pathogen increases the probability of vector dispersal, and that such movem ...201526083763
quantitative real-time pcr for detection and identification of candidatus liberibacter species associated with citrus huanglongbing.citrus huanglongbing (hlb, ex greening) is one of the most serious diseases of citrus. different forms of the disease are caused by different candidatus liberobacter species, candidatus liberibacter asiaticus (las), ca. l. africanus (laf) and ca. l. americanus (lam). the pathogen is transmitted by psyllid insects and by budding with contaminated plant materials. the vector psyllid diaphorina citri can transmit both las and lam. establishment of this vector into florida, reports of lam and las in ...200616414133
innate immune system capabilities of the asian citrus psyllid, diaphorina citri.citrus production worldwide is currently threatened by huanglongbing, or citrus greening disease. the associated pathogen, candidatus liberibacter asiaticus (clas), is transmitted by the asian citrus psyllid, diaphorina citri. annotation of the d. citri genome revealed a reduced innate immune system lacking a number of antimicrobial peptides and the imd pathway associated with defense against gram-negative bacteria. we characterized this apparent immune reduction in survival assays in which d. c ...201728624621
effects of pymetrozine, an antifeedant of hemiptera, on asian citrus psyllid, diaphorina citri, feeding behavior, survival and transmission of candidatus liberibacter asiaticus.vector-borne plant disease management can be enhanced by deployment of antifeedants in addition to the use of broad-spectrum neurotoxic insecticides. the effects of pymetrozine on asian citrus psyllid (acp), diaphorina citri kuwayama, feeding behaviour, survival and transmission of candidatus liberibacter asiaticus (las), the presumed causal pathogen of huanglongbing, were investigated.201020960465
effect of candidatus liberibacter asiaticus infection on susceptibility of asian citrus psyllid, diaphorina citri, to selected insecticides.in the present investigation, the effect of candidatus liberibacter asiaticus (las), a bacterium considered to be responsible for causing huanglongbing (hlb) disease in citrus, on the physiology of its vector, the asian citrus psyllid (acp) diaphorina citri kuwayama, was determined. specifically, the effects of las infection on the susceptibility of acp to selected insecticides were determined. furthermore, total protein content and general esterase activity were quantified in las-infected and u ...201020960471
analyses of mitogenome sequences revealed that asian citrus psyllids (diaphorina citri) from california were related to those from florida.asian citrus psyllid (acp, diaphorina citri kuwayama) transmits "candidatus liberibacter asiaticus" (clas), an unculturable alpha-proteobacterium associated with citrus huanglongbing (hlb). clas has recently been found in california. understanding acp population diversity is necessary for hlb regulatory practices aimed at reducing clas spread. in this study, two circular acp mitogenome sequences from california (mt-capsy, ~15,027 bp) and florida (mt-flpsy, ~15,012 bp), usa, were acquired. each m ...201728860662
combining 'omics and microscopy to visualize interactions between the asian citrus psyllid vector and the huanglongbing pathogen candidatus liberibacter asiaticus in the insect gut.huanglongbing, or citrus greening disease, is an economically devastating bacterial disease of citrus. it is associated with infection by the gram-negative bacterium candidatus liberibacter asiaticus (clas). clas is transmitted by diaphorina citri, the asian citrus psyllid (acp). for insect transmission to occur, clas must be ingested during feeding on infected phloem sap and cross the gut barrier to gain entry into the insect vector. to investigate the effects of clas exposure at the gut-pathog ...201728632769
comprehensive meta-analysis, co-expression, and mirna nested network analysis identifies gene candidates in citrus against huanglongbing disease.huanglongbing (hlb), the most devastating disease of citrus, is associated with infection by candidatus liberibacter asiaticus (calas) and is vectored by the asian citrus psyllid (acp). recently, the molecular basis of citrus-hlb interactions has been examined using transcriptome analyses, and these analyses have identified many probe sets and pathways modulated by calas infection among different citrus cultivars. however, lack of consistency among reported findings indicates that an integrative ...201526215595
a small wolbachia protein directly represses phage lytic cycle genes in "candidatus liberibacter asiaticus" within psyllids.huanglongbing (hlb) is a severe disease of citrus caused by an uncultured alphaproteobacterium "candidatus liberibacter asiaticus" and transmitted by asian citrus psyllids (diaphorina citri). two prophage genomes, sc1 and sc2, integrated in "ca. liberibacter asiaticus" strain uf506 were described previously, and very similar prophages are found resident in the majority of "ca. liberibacter asiaticus" strains described worldwide. the sc1 lytic cycle is marked by upregulation of prophage late gene ...201728608866
draft whole-genome sequence of "candidatus liberibacter asiaticus" strain tx2351 isolated from asian citrus psyllids in texas, usa.we report here the draft genome sequence of "candidatus liberibacter asiaticus" strain tx2351, collected from asian citrus psyllids in south texas, usa. the tx2351 genome has a size of 1,252,043 bp, a g+c content of 36.5%, 1,184 predicted open reading frames, and 52 rna genes.201728408682
ldtr is a master regulator of gene expression in liberibacter asiaticus.huanglongbing or citrus greening disease is causing devastation to the citrus industry. liberibacter asiaticus, an obligate intracellular pathogen of citrus, is one the causative agents of the disease. most of the knowledge about this bacterium has been deduced from the in silico exploration of its genomic sequence. l. asiaticus differentially expresses genes during its transmission from the psyllid vector, diaphorina citri, to the plant. however, the regulatory mechanisms for the adaptation of ...201728503858
occurrence of free fatty acids in the phloem sap of different citrus varieties.candidatus liberibacter asiaticus is a phloem restricted bacterium causes citrus greening disease or huanglongbing (hlb), a major treat to commercial citrus production in florida. it is transmitted by the asian citrus psyllid, a phloem sap-feeding insect. studies conducted on the composition of citrus phloem sap revealed the presence amino acids, organic acids and sugars and of low amounts of free fatty acids. in the present study, the phloem sap of twelve citrus varieties with different degrees ...028532234
a plant pathogenic bacterium exploits the tricarboxylic acid cycle metabolic pathway of its insect vector.huanglongbing in citrus is caused by a phloem-limited, uncultivable, gram-negative α-proteobacterium, candidatus liberibacter asiaticus (clas). clas is transmitted by the phloem-sucking insect, diaphorina citri (hemiptera: liviidae), in a persistent, circulative, and propagative manner. in this study, we investigated the metabolomic and respiration rates changes in d. citri upon infection with clas using gas chromatography-mass spectrometry (gc-ms) and gas exchange analysis. the level of glycine ...028594267
Displaying items 1 - 69 of 69