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 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 ).

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.

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.

Expression and purification of cellulase Xf818 from Xylella fastidiosa in Escherichia coli.

Xylella fastidiosa was the first plant pathogen whose complete genome sequence was available. X. fastidiosa causes citrus variegated chlorosis, but the physiological basis of the disease in unknown.