Comparative genetic mapping and a consensus interspecific genetic map reveal strong synteny and collinearity within the genus.

Introduction: Useful germplasm for citrus breeding includes all sexually compatible species of the former genera , and , now merged in the single genus. An improved knowledge on the synteny/collinearity between the genome of these different species, and on their recombination landscapes, is essential to optimize interspecific breeding schemes.

Method: We have performed a large comparative genetic mapping study including several main clades of the genus.

The complete genome sequence of " Liberibacter asiaticus" strain 9PA and the characterization of field strains in the Brazilian citriculture.

Unlabelled: " Liberibacter asiaticus" (CLas) is associated with citrus huanglongbing, a severe disease with global importance that affects citrus production in Brazil. This study reports the first complete genome of a Brazilian strain of CLas. The genomic structure comparison of strain 9PA with those of 13 complete CLas genomes revealed 9,091 mismatches and 992 gaps/insertions, highlighting eight locally colinear blocks, among which six are in the prophage region.

Impedimetric immunosensor versus qPCR for Huanglongbing detection.

Citriculture is facing challenges due to the spread of various diseases, among which the most threatening, with worldwide occurrence, is Huanglongbing (HLB), caused by the bacteria Candidatus Liberibacter spp., vectored by psyllids. In orchards, HLB-infected plants are identified by visual observation of symptoms.

Multiplex qPCR for the detection of bacteria associated with huanglongbing ' Liberibacter asiaticus', '. L. americanus' and 16Sr IX group phytoplasma.

The occurrence of 'Candidatus Liberibacter' spp. and '. Phytoplasma' spp.

The greening-causing agent alters the behavioral and electrophysiological responses of the Asian citrus psyllid to a putative sex pheromone.

The Asian Citrus Psyllid (ACP), Diaphorina citri, is a vector of the pathological bacterium Candidatus Liberibacter asiaticus (CLas), which causes the most devastating disease to the citrus industry worldwide, known as greening or huanglongbing (HLB). Earlier field tests with an acetic acid-based lure in greening-free, 'Valencia' citrus orange groves in California showed promising results. The same type of lures tested in São Paulo, Brazil, showed unsettling results.

Insight into resistance to ' Liberibacter asiaticus,' associated with Huanglongbing, in Oceanian citrus genotypes.

Huanglongbing (HLB), the most destructive citrus disease, is associated with unculturable, phloem-limited Liberibacter species, mainly L. asiaticus (Las). Las is transmitted naturally by the insect .

The molecular interplay of the establishment of an infection - gene expression of Diaphorina citri gut and Candidatus Liberibacter asiaticus.

Background: Candidatus Liberibacter asiaticus (CLas) is one the causative agents of greening disease in citrus, an unccurable, devastating disease of citrus worldwide. CLas is vectored by Diaphorina citri, and the understanding of the molecular interplay between vector and pathogen will provide additional basis for the development and implementation of successful management strategies. We focused in the molecular interplay occurring in the gut of the vector, a major barrier for CLas invasion and colonization.

Prevalent Transmission of Liberibacter asiaticus' over '. Liberibacter americanus' in a Long-Term Controlled Environment.

In Brazil, citrus huanglongbing (HLB) is associated with ' Liberibacter americanus' (CLam) and ' Liberibacter asiaticus' (CLas). However, there are few studies about HLB epidemiology when both Liberibacter spp. and its insect vector, the Asian citrus psyllid (ACP, ), are present.

The Genome of " Liberibacter asiaticus" Is Highly Transcribed When Infecting the Gut of .

The Asian citrus psyllid, , is the vector of the bacterium " Liberibacter asiaticus" (Las), associated with the devastating, worldwide citrus disease huanglongbing. In order to explore the molecular interactions of this bacterium with during the vector acquisition process, cDNA libraries were sequenced on an Illumina platform, obtained from the gut of adult psyllids confined in healthy (H) and in Las-infected young shoots (Las) for different periods of times (I = 1/2 days, II = 3/4 days, and III = 5/6 days). In each sampling time, three biological replicates were collected, containing 100 guts each, totaling 18 libraries depleted in ribosomal RNA.

Engineered Orange Ectopically Expressing the Arabidopsis β-Caryophyllene Synthase Is Not Attractive to , the Vector of the Bacterial Pathogen Associated to Huanglongbing.

Huanglongbing (HLB) is a destructive disease, associated with psyllid-transmitted phloem-restricted pathogenic bacteria, which is seriously endangering citriculture worldwide. It affects all citrus species and cultivars regardless of the rootstock used, and despite intensive research in the last decades, there is no effective cure to control either the bacterial species ( Liberibacter spp.) or their insect vectors ( and ).

Resistance to ' Liberibacter asiaticus,' the Huanglongbing Associated Bacterium, in Sexually and/or Graft-Compatible Relatives.

Huanglongbing (HLB) is the most destructive, yet incurable disease of citrus. Finding sources of genetic resistance to HLB-associated ' Liberibacter asiaticus' (Las) becomes strategic to warrant crop sustainability, but no resistant genotypes exist. Some relatives of the family Rutaceae, subfamily Aurantioideae, were described as full-resistant to Las, but they are phylogenetically far, thus incompatible with .

Incidence of Carrying Liberibacter asiaticus in Brazil's Citrus Belt.

Huanglongbing (HLB) is a citrus disease of worldwide importance, associated with the presence of Liberibacter asiaticus (Las) and vectored by the psyllid in Asia and the Americas. To properly manage HLB, removal of inoculum sources and control of the psyllid are undertaken. We evaluated the percentage of the psyllid population with Las, sampled from yellow sticky traps over a three-year period and its relationship with insect population, regions, season of the year, and HLB management in citrus areas in the southwestern, central, and northern regions of São Paulo (SP) and southwestern region of Minas Gerais states, Brazil.

Mass spectrometry imaging as a potential technique for diagnostic of Huanglongbing disease using fast and simple sample preparation.

Huanglongbing (HLB) is a disease of worldwide incidence that affects orange trees, among other commercial varieties, implicating in great losses to the citrus industry. The disease is transmitted through Diaphorina citri vector, which inoculates Candidatus Liberibacter spp. in the plant sap.

Behavioral responses of Diaphorina citri to host plant volatiles in multiple-choice olfactometers are affected in interpretable ways by effects of background colors and airflows.

In several phytophagous hemipterans, behavior appears to be mediated by both visual and chemical cues. For the Asian citrus psyllid (ACP) Diaphorina citri (Hemiptera: Liviidae), olfactometric assays are generally difficult to interpret owing to the low proportion of individuals responding to odors (~30-40%), which compromises the efficiency and reliability of the results of behavioral tests. In the present study, the ACP behavioral response to emitted odors from sweet orange (Citrus sinensis L.

Drench Application of Systemic Insecticides Disrupts Probing Behavior of (Hemiptera: Liviidae) and Inoculation of Liberibacter asiaticus.

Liberibacter asiaticus (Las) is a phloem-limited bacterium that is associated with the Huanglongbing (HLB) disease of citrus and transmitted by the psyllid, . There are no curative methods to control HLB and the prevention of new infections is essential for HLB management. Therefore, the objective of our study was to determine the effects of systemic insecticides, such as the neonicotinoids imidacloprid, thiamethoxam, and a mixture of thiamethoxam and chlorantraniliprole (diamide) on the probing behavior of Las-infected and their effect on Las transmission.

Genetic Diversity of ' Liberibacter asiaticus' Revealed by Short Tandem Repeats and Prophage Typing Indicates Population Homogeneity in Brazil.

' Liberibacter asiaticus' is the most common huanglongbing-associated bacteria, being present in Asia, South, Central, and North America. Genomic approaches enabled sequencing of '. L.

Molecular Characterization and Detection of 16SrIII Group Phytoplasma Associated with Huanglongbing Symptoms.

When huanglongbing (HLB) was found in Brazil in 2004, 'Candidatus Liberibacter americanus' was infecting most of the trees while 'Ca. L. asiaticus' was present in a minor proportion.

β-caryophyllene emitted from a transgenic Arabidopsis or chemical dispenser repels Diaphorina citri, vector of Candidatus Liberibacters.

Production of citrus, the main fruit tree crop worldwide, is severely threatened by Huanglongbing (HLB), for which as yet a cure is not available. Spread of this bacterial disease in America and Asia is intimately connected with dispersal and feeding of the insect vector Diaphorina citri, oligophagous on rutaceous host plants. Effective control of this psyllid is an important component in successful HLB management programs.

The complete genome sequence of 'Candidatus Liberibacter americanus', associated with Citrus huanglongbing.

Liberibacter spp. form a Rhizobiaceae clade of phloem-limited pathogens of limited host range. Two obligately parasitic species have been sequenced: 'Candidatus Liberibacter asiaticus', which causes citrus huanglongbing (HLB) worldwide, and 'Ca.

Citrus Sudden Death Is Transmitted by Graft-Inoculation and Natural Transmission Is Prevented by Individual Insect-Proof Cages.

Citrus sudden death (CSD) transmission was studied by graft-inoculation and under natural conditions. Young sweet orange trees on Rangpur rootstock were used as indicator plants. They were examined regularly for one or two characteristic markers of CSD: (i) presence of a yellow-stained layer of thickened bark on the Rangpur rootstock, and (ii) infection with the CSD-associated marafivirus.

'Ca. Liberibacter asiaticus' carries an excision plasmid prophage and a chromosomally integrated prophage that becomes lytic in plant infections.

Huanglongbing (HLB), also known as citrus greening, is a lethal disease of citrus caused by several species of 'Candidatus Liberibacter', a psyllid-transmitted, phloem-limited, alpha proteobacteria. 'Ca. Liberibacter asiaticus' is widespread in Florida citrus.

Effects of the antimicrobial peptide gomesin on the global gene expression profile, virulence and biofilm formation of Xylella fastidiosa.

In the xylem vessels of susceptible hosts, such as citrus trees, Xylella fastidiosa forms biofilm-like colonies that can block water transport, which appears to correlate to disease symptoms. Besides aiding host colonization, bacterial biofilms play an important role in resistance against antimicrobial agents, for instance antimicrobial peptides (AMPs). Here, we show that gomesin, a potent AMP from a tarantula spider, modulates X.

Nuclear magnetic resonance characterization of metabolite disorder in orange trees caused by citrus sudden death disease.

Citrus sudden death (CSD) is a new disease of sweet orange and mandarin trees grafted on Rangpur lime and Citrus volkameriana rootstocks. It was first seen in Brazil in 1999, and has since been detected in more than four million trees. The CSD causal agent is unknown and the current hypothesis involves a virus similar to Citrus tristeza virus or a new virus named Citrus sudden death-associated virus.

Influence of culture medium pH on growth, aggregation, and biofilm formation of Xylella fastidiosa.

The major feature of Xylella fastidiosa growing in its hosts, as well as in culture media, is its cellular aggregation and biofilm formation, leading to partial obstruction of the xylem causing water stress in the plant. We report that growth, aggregation, and biofilm formation of X. fastidiosa are influenced by the medium pH.

Distribution and quantification of Candidatus Liberibacter americanus, agent of huanglongbing disease of citrus in São Paulo State, Brasil, in leaves of an affected sweet orange tree as determined by PCR.

Huanglongbing (HLB), an insect-transmitted disease of citrus, known for many years in Asia and Africa, has appeared in the state of São Paulo State (SSP), Brazil, in 2004, and the state of Florida, USA, in 2005. HLB endangers the very existence of citrus, as trees infected with the bacterial pathogen, irrevocably decline. In the absence of curative procedures, control of HLB is difficult and only based on prevention.