| 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 ... | 2015 | 26470202 |
| 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 ... | 2015 | 26470150 |
| 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 ... | 2015 | 26470097 |
| 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 ... | 2015 | 26034273 |
| 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 ... | 2015 | 25819961 |
| 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 ... | 2017 | 28282380 |
| 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 ... | 2017 | 28278248 |
| 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 ... | 2015 | 25256398 |
| 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 ... | 2014 | 24769405 |
| rapid, sensitive, and carryover contamination-free loop-mediated isothermal amplification-coupled visual detection method for 'candidatus liberibacter asiaticus'. | huanglongbing is a devastating citrus disease, and 'candidatus liberibacter asiaticus' (las) is the most prevalent huanglongbing-associated bacterium. its field detection remains challenging. in this work, a visual, rapid, sensitive, and carryover contamination-free method was developed for field detection of las. leaf samples were treated with 500 μl of 0.5 m sodium hydroxide solution for 3 min, and 50-fold dilutions were directly amplified by loop-mediated isothermal amplification. then, a nov ... | 2017 | 28858491 |
| huanglongbing impairs the rhizosphere-to-rhizoplane enrichment process of the citrus root-associated microbiome. | roots are the primary site for plant-microbe interactions. among the three root-associated layers (i.e., rhizosphere, rhizoplane, and endorhiza), the rhizoplane is a key component serving a critical gating role that controls microbial entry into plant roots. the microbial communities colonizing the three layers are believed to be gradually enriched from the bulk soil inoculum. however, it is unknown how this enrichment process, particularly the rhizosphere to rhizoplane step, is affected by biot ... | 2017 | 28797279 |
| 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 ... | 2013 | 23955888 |
| 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 ... | 2016 | 27667799 |
| psyllids, it's what's on the inside that counts: community cross talk facilitates prophage interactions. | despite the availability of massive microbial community data sets (e.g., metagenomes), there is still a lack of knowledge on what molecular mechanisms facilitate cross talk between microbes and prophage within a community context. a study published in msphere by jain and colleagues (m. jain, l. a. fleites, and d. w. gabriel, msphere 2:e00171-17, 2017, https://doi.org/10.1128/mspheredirect.00171-17) reports on an intriguing new twist of how a prophage of the bacterium "candidatus liberibacter asi ... | 2017 | 28612849 |
| 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 ... | 2016 | 27418697 |
| 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 ... | 2016 | 27193763 |
| immune tissue print and immune capture-pcr for diagnosis and detection of candidatus liberibacter asiaticus. | 'candidatus liberibacter asiaticus' (calas), associated with citrus huanglongbing (hlb), is a non culturable member of the α-proteobacteria. in this study serologically based methods for the detection of calas were developed. an anti-outer membrane protein a (ompa) polyclonal antibody previously produced (in our laboratory) was highly effective for the detection of calas from citrus tissues in a simple tissue printing format. the antibody was also used to capture bacteria from periwinkle extract ... | 2017 | 28418002 |
| 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. | 2017 | 28408682 |
| 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 ... | 2016 | 26846216 |
| crystal structure analysis in zn(2+)-bound state and biophysical characterization of clas-znua2. | a periplasmic solute binding protein from second of the two gene clusters of znu system in cla (clas-znua2) belong to cluster a1 family of solute binding proteins (sbps). the crystal structures in metal-free, intermediate and metal-bound states, in the previous study, revealed the unusual mechanism of metal binding and release for clas-znua2. although clas-znua2 showed maximum sequence identity to the mn/fe-specific sbps, the mechanistic resemblance seems to be closer to zn-specific sbps of clus ... | 2016 | 27570147 |
| 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 ... | 2015 | 26717484 |
| 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. | 2015 | 26543132 |
| zinc treatment increases the titre of 'candidatus liberibacter asiaticus' in huanglongbing-affected citrus plants while affecting the bacterial microbiomes. | huanglongbing (hlb)-affected citrus often display zinc deficiency symptoms. in this study, supplemental zinc was applied to citrus to determine its effect on candidatus liberibacter asiaticus (las) titre, hlb symptoms, and leaf microbiome. | 2016 | 26909469 |
| 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 ... | 2017 | 26537022 |
| draft genome sequence of "candidatus liberibacter asiaticus" from a citrus tree in san gabriel, california. | the draft genome sequence of "candidatus liberibacter asiaticus" strain sgca5 from an orange citrus tree in san gabriel, california, is reported here. sgca5 has a genome size of 1,201,445 bp, a g+c content of 36.4%, 1,152 predicted open reading frames (orfs), and 42 rna genes. | 2015 | 26701083 |
| 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 ... | 2015 | 26215595 |
| whole-genome sequence of "candidatus liberibacter asiaticus" from a huanglongbing-affected citrus tree in central florida. | here, we report the draft genome sequence of "candidatus liberibacter asiaticus" strain fl17, isolated from a huanglongbing (hlb)-affected citrus tree in central florida. the fl17 genome comprised 1,227,253 bp, with a g+c content of 36.5%, 1,175 predicted open reading frames, and 53 rna genes. | 2015 | 25792067 |
| 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 ... | 2012 | 22529882 |
| effective antibiotics against 'candidatus liberibacter asiaticus' in hlb-affected citrus plants identified via the graft-based evaluation. | citrus huanglongbing (hlb), caused by three species of fastidious, phloem-limited 'candidatus liberibacter', is one of the most destructive diseases of citrus worldwide. to date, there is no established cure for this century-old and yet, newly emerging disease. as a potential control strategy for citrus hlb, 31 antibiotics were screened for effectiveness and phytotoxicity using the optimized graft-based screening system with 'candidatus liberibacter asiaticus' (las)-infected citrus scions. actid ... | 2014 | 25372135 |
| draft genome sequence of "candidatus liberibacter asiaticus" from california. | we report here the draft genome sequence of "candidatus liberibacter asiaticus" strain hhca, collected from a lemon tree in california. the hhca strain has a genome size of 1,150,620 bp, 36.5% g+c content, 1,119 predicted open reading frames, and 51 rna genes. | 2014 | 25278540 |
| 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 ... | 2012 | 22457628 |
| 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 ... | 2017 | 28624621 |
| whole-genome sequence of "candidatus liberibacter asiaticus" from guangdong, china. | the draft genome sequence of "candidatus liberibacter asiaticus" strain a4, isolated from a mandarin citrus in guangdong, people's republic of china, is reported. the a4 strain has a genome size of 1,208,625 bp, g+c content of 36.4%, 1,107 predicted open reading frames, and 53 rna genes. | 2014 | 24723715 |
| 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 ... | 0 | 28594267 |
| gene regulatory networks elucidating huanglongbing disease mechanisms. | next-generation sequencing was exploited to gain deeper insight into the response to infection by candidatus liberibacter asiaticus (calas), especially the immune disregulation and metabolic dysfunction caused by source-sink disruption. previous fruit transcriptome data were compared with additional rna-seq data in three tissues: immature fruit, and young and mature leaves. four categories of orchard trees were studied: symptomatic, asymptomatic, apparently healthy, and healthy. principal compon ... | 2013 | 24086326 |
| 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 ... | 0 | 28532234 |
| defining the core citrus leaf- and root-associated microbiota: factors associated with community structure and implications for managing huanglongbing (citrus greening) disease. | stable associations between plants and microbes are critical to promoting host health and productivity. the objective of this work was to test the hypothesis that restructuring of the core microbiota may be associated with the progression of huanglongbing (hlb), the devastating citrus disease caused by liberibacter asiaticus, liberibacter americanus, and liberibacter africanus the microbial communities of leaves (n = 94) and roots (n = 79) from citrus trees that varied by hlb symptom severity, c ... | 2017 | 28341678 |
| characterization of the microbial community structure in candidatus liberibacter asiaticus-infected citrus plants treated with antibiotics in the field. | huanglongbing (hlb) is a worldwide devastating disease of citrus. there are no effective control measures for this newly emerging but century-old disease. previously, we reported a combination of penicillin g and streptomycin was effective in eliminating or suppressing the associated bacterium, 'candidatus liberibacter asiaticus' (las). | 2013 | 23701743 |
| identification of the tolfenamic acid binding pocket in prbp from liberibacter asiaticus. | in liberibacter asiaticus, prbp is an important transcriptional accessory protein that was found to regulate gene expression through interactions with the rna polymerase β-subunit and a specific sequence on the promoter region. it was found that inactivation of prbp, using the inhibitor tolfenamic acid, resulted in a significant decrease in the overall transcriptional activity of l. asiaticus, and the suppression of l. asiaticus infection in hlb symptomatic citrus seedlings. the molecular intera ... | 2017 | 28878750 |
| 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 ... | 2017 | 28860662 |
| messa: meta-server for protein sequence analysis. | computational sequence analysis, that is, prediction of local sequence properties, homologs, spatial structure and function from the sequence of a protein, offers an efficient way to obtain needed information about proteins under study. since reliable prediction is usually based on the consensus of many computer programs, meta-severs have been developed to fit such needs. most meta-servers focus on one aspect of sequence analysis, while others incorporate more information, such as predictprotein ... | 2012 | 23031578 |
| sensitive and robust detection of citrus greening (huanglongbing) bacterium "candidatus liberibacter asiaticus" by dna amplification with new 16s rdna-specific primers. | citrus greening disease is caused by "candidatus liberibacter spp.," including "candidatus liberibacter asiaticus (las)." for detecting this disease, we designed new primers from the las 16s rdna and used a very small dna template for pcr. more las-infected tissues were detected with our primers than with the common primers. | 2012 | 22728344 |
| bacterial phytopathogen infection disrupts belowground plant indirect defense mediated by tritrophic cascade. | plants can defend themselves against herbivores through activation of defensive pathways and attraction of third-trophic-level predators and parasites. trophic cascades that mediate interactions in the phytobiome are part of a larger dynamic including the pathogens of the plant itself, which are known to greatly influence plant defenses. as such, we investigated the impact of a phloem-limited bacterial pathogen, candidatus liberibacter asiaticus (clas), in cultivated citrus rootstock on a well-s ... | 2017 | 28690813 |
| 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 ... | 2017 | 28632769 |
| 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 ... | 2013 | 23857364 |
| 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 ... | 2013 | 23734251 |
| 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 ... | 2013 | 23660656 |
| 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 ... | 2013 | 23555830 |
| 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 ... | 2013 | 23336388 |
| 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 ... | 2017 | 28608866 |
| 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 ... | 2013 | 23317046 |
| 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 ... | 2017 | 28503858 |
| characterization of a bacterioferritin comigratory protein family 1-cys peroxiredoxin from candidatus liberibacter asiaticus. | to defend against the lethality of the reactive oxygen species (ros), nature has armed microorganisms with a range of antioxidant proteins. these include peroxiredoxin (prx) super family proteins which are ubiquitous cysteine-based non-heme peroxidases. the phytopathogenic bacterium candidatus liberibacter asiaticus (cla), an etiological agent of citrus plants diseases, posses many genes for defense against oxidative stress. the bacterioferritin comigratory protein (bcp), a member of prxs, is pa ... | 2017 | 27987036 |
| transient expression of candidatus liberibacter asiaticus effector induces cell death in nicotiana benthamiana. | candidatus liberibacter asiaticus "las" is a phloem-limited bacterial plant pathogen, and the most prevalent species of liberibacter associated with citrus huanglongbing (hlb), a devastating disease of citrus worldwide. although, the complete sequence of the las genome provides the basis for studying functional genomics of las and molecular mechanisms of las-plant interactions, the functional characterization of las effectors remains a slow process since remains to be cultured. like other plant ... | 2016 | 27458468 |
| identification of the genes required for the culture of liberibacter crescens, the closest cultured relative of the liberibacter plant pathogens. | here tn5 random transposon mutagenesis was used to identify the essential elements for culturing liberibacter crescens bt-1 that can serve as antimicrobial targets for the closely related pathogens of citrus, candidatus liberibacter asiaticus (las) and tomato and potato, candidatus liberibacter solanacearum (lso). in order to gain insight on the virulence, metabolism, and culturability of the pathogens within the genus liberibacter, a mini-tn5 transposon derivative system consisting of a gene sp ... | 2016 | 27148230 |
| predominance of single prophage carrying a crispr/cas system in "candidatus liberibacter asiaticus" strains in southern china. | "candidatus liberibacter asiaticus" (clas) is an uncultureable α-proteobacterium associated with citrus huanglongbing (hlb, yellow shoot disease), a highly destructive disease affecting citrus production worldwide. hlb was observed in guangdong province of china over a hundred years ago and remains endemic there. little is known about clas biology due to its uncultureable nature. this study began with the genome sequence analysis of clas strain a4 from guangdong in the prophage region. within th ... | 2016 | 26741827 |
| 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 ... | 2012 | 23156142 |
| 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. | 2012 | 22653617 |
| metabolite signature of candidatus liberibacter asiaticus infection in two citrus varieties. | huanglongbing (hlb), also known as citrus greening disease, is caused by the bacterium 'candidatus liberibacter asiaticus' (clas) and is a serious threat to the citrus industry. to understand the effect of clas infection on the citrus metabolome, juice from healthy (n = 18), hlb-asymptomatic (n = 18), and hlb-symptomatic hamlin (n = 18), as well as from healthy (n = 18) and hlb-symptomatic (n = 18) valencia sweet oranges (from southern and eastern florida) were evaluated using (1)h nmr-based met ... | 2014 | 24959841 |
| characterization of "candidatus liberibacter asiaticus" populations by double-locus analyses. | "candidatus liberibacter asiaticus" (calas) is associated with citrus huanglongbing (hlb, yellow shoot disease), which is highly destructive to world citrus production. understanding the relationships of calas isolates from different geographical regions is important for hlb research and development of disease management strategies. in this study, 301 calas isolates [85 brazil, 132 china, and 84 u.s. (83 florida and 1 california)] were collected, and genomic variations among them were evaluated ... | 2014 | 24912994 |
| spatial imaging of zn and other elements in huanglongbing-affected grapefruit by synchrotron-based micro x-ray fluorescence investigation. | huanglongbing (hlb) is a highly destructive, fast-spreading disease of citrus, causing substantial economic losses to the citrus industry worldwide. nutrient levels and their cellular distribution patterns in stems and leaves of grapefruit were analysed after graft-inoculation with lemon scions containing 'candidatus liberibacter asiaticus' (las), the heat-tolerant asian type of the hlb bacterium. after 12 months, affected plants showed typical hlb symptoms and significantly reduced zn concentra ... | 2014 | 24420564 |
| transcriptional and microscopic analyses of citrus stem and root responses to candidatus liberibacter asiaticus infection. | huanglongbing (hlb) is the most destructive disease that affects citrus worldwide. the disease has been associated with candidatus liberibacter. hlb diseased citrus plants develop a multitude of symptoms including zinc and copper deficiencies, blotchy mottle, corky veins, stunting, and twig dieback. ca. l. asiaticus infection also seriously affects the roots. previous study focused on gene expression of leaves and fruit to ca. l. asiaticus infection. in this study, we compared the gene expressio ... | 2013 | 24058486 |
| extraction of dna from orange juice, and detection of bacterium candidatus liberibacter asiaticus by real-time pcr. | orange juice processed from huanglongbing (hlb) affected fruit is often associated with bitter taste and/or off-flavor. hlb disease in florida is associated with candidatus liberibacter asiaticus (clas), a phloem-limited bacterium. the current standard to confirm clas for citrus trees is to take samples from midribs of leaves, which are rich in phloem tissues, and use a quantitative real-time polymerase chain reaction (qpcr) test to detect the 16s rdna gene of clas. it is extremely difficult to ... | 2013 | 24047134 |
| complete genome sequence of a chinese strain of "candidatus liberibacter asiaticus". | we report here the complete genome sequence of "candidatus liberibacter asiaticus" (strain guangxi-1). the 1,268,237-bp genome with a 36.5% g+c content comprises 1,141 open reading frames, 44 trnas, and 3 complete rrnas in a circular chromosome. | 2013 | 23640196 |
| transcriptome comparison and gene coexpression network analysis provide a systems view of citrus response to 'candidatus liberibacter asiaticus' infection. | huanglongbing (hlb) is arguably the most destructive disease for the citrus industry. hlb is caused by infection of the bacterium, candidatus liberibacter spp. several citrus genechip studies have revealed thousands of genes that are up- or down-regulated by infection with ca. liberibacter asiaticus. however, whether and how these host genes act to protect against hlb remains poorly understood. | 2013 | 23324561 |
| transcriptome profiling of citrus fruit response to huanglongbing disease. | huanglongbing (hlb) or "citrus greening" is the most destructive citrus disease worldwide. in this work, we studied host responses of citrus to infection with candidatus liberibacter asiaticus (calas) using next-generation sequencing technologies. a deep mrna profile was obtained from peel of healthy and hlb-affected fruit. it was followed by pathway and protein-protein network analysis and quantitative real time pcr analysis of highly regulated genes. we identified differentially regulated path ... | 2012 | 22675433 |
| crystal structure of a periplasmic solute binding protein in metal-free, intermediate and metal-bound states from candidatus liberibacter asiaticus. | the znu system, a member of abc transporter family, is critical for survival and pathogenesis of candidatus liberibacter asiaticus (cla). two homologues of this system have been identified in cla. here, we report high resolution crystal structure of a periplasmic solute binding protein from second of the two gene clusters of znu system in cla (clas-znua2) in metal-free, intermediate and metal-bound states. clas-znua2 showed maximum sequence identity to the mn/fe-specific solute binding proteins ... | 2015 | 25641618 |