Temporal Progress of Huanglongbing Epidemics and the Effect of Noncommercial Inoculum Sources on Citrus Orchards in São Paulo State, Brazil.

Huanglongbing (HLB) incidence is increasing and threatening citrus production in São Paulo State, Brazil, despite multiple efforts to control the disease and its vector, the Asian citrus psyllid (ACP) (). The objective of this research was to study the temporal dynamics of HLB epidemics, under intensive disease management, in 177 individual commercial citrus blocks on a single property in São Paulo State. The effect of internal and external sources of HLB-associated bacteria and its vector were explored based on the disease epidemics and vector dynamics in the studied area.

Relative Contribution of Windbreak, Copper Sprays, and Leafminer Control for Citrus Canker Management and Prevention of Crop Loss in Sweet Orange Trees.

The management of citrus canker, caused by subsp. , has been widely studied in endemic areas because of the importance of the disease in several citrus-producing countries. A set of control measures is well established, but no study has investigated the efficiency of each measure individually and their combination for disease suppression.

Periplasm-enriched fractions from Xanthomonas citri subsp. citri type A and X. fuscans subsp. aurantifolii type B present distinct proteomic profiles under in vitro pathogenicity induction.

The causative agent of Asiatic citrus canker, the Gram-negative bacterium Xanthomonas citri subsp. citri (XAC), produces more severe symptoms and attacks a larger number of citric hosts than Xanthomonas fuscans subsp. aurantifolii XauB and XauC, the causative agents of cancrosis, a milder form of the disease.

CitrusKB: a comprehensive knowledge base for transcriptome and interactome of Citrus spp. infected by Xanthomonas citri subsp. citri at different infection stages.

Citrus canker type A is a serious disease caused by Xanthomonas citri subsp. citri (X. citri), which is responsible for severe losses to growers and to the citrus industry worldwide.

Analyses of Seven New Genomes of pv. Strains, Causative Agents of Citrus Canker B and C, Show a Reduced Repertoire of Pathogenicity-Related Genes.

pv. pathotype B (XauB) and pathotype C (XauC) are the causative agents respectively of citrus canker B and C, diseases of citrus plants related to the better-known citrus canker A, caused by pv. .

Origin and diversification of Xanthomonas citri subsp. citri pathotypes revealed by inclusive phylogenomic, dating, and biogeographic analyses.

Background: Xanthomonas citri subsp. citri pathotypes cause bacterial citrus canker, being responsible for severe agricultural losses worldwide. The A pathotype has a broad host spectrum, while A* and A are more restricted both in hosts and in geography.

Detection of citrus canker and Huanglongbing using fluorescence imaging spectroscopy and support vector machine technique.

Citrus canker and Huanglongbing (HLB) are citrus diseases that represent a serious threat to the citrus production worldwide and may cause large economic losses. In this work, we combined fluorescence imaging spectroscopy (FIS) and a machine learning technique to discriminate between these diseases and other ordinary citrus conditions that may be present at citrus orchards, such as citrus scab and zinc deficiency. Our classification results are highly accurate when discriminating citrus canker from citrus scab (97.

Temperature stress promotes cell division arrest in Xanthomonas citri subsp. citri.

Citrus canker is an economically important disease that affects orange production in some of the most important producing areas around the world. It represents a great threat to the Brazilian and North American citriculture, particularly to the states of São Paulo and Florida, which together correspond to the biggest orange juice producers in the world. The etiological agent of this disease is the Gram-negative bacterium Xanthomonas citri subsp.

A TALE of transposition: Tn3-like transposons play a major role in the spread of pathogenicity determinants of Xanthomonas citri and other xanthomonads.

Unlabelled: Members of the genus Xanthomonas are among the most important phytopathogens. A key feature of Xanthomonas pathogenesis is the translocation of type III secretion system (T3SS) effector proteins (T3SEs) into the plant target cells via a T3SS. Several T3SEs and a murein lytic transglycosylase gene (mlt, required for citrus canker symptoms) are found associated with three transposition-related genes in Xanthomonas citri plasmid pXAC64.

Comparison of Resistance to Asiatic Citrus Canker Among Different Genotypes of Citrus in a Long-Term Canker-Resistance Field Screening Experiment in Brazil.

Asiatic citrus canker (ACC) is caused by Xanthomonas citri subsp. citri. The disease results in yield loss and renders fruit unfit for the fresh market.

Asymmetric chromosome segregation in Xanthomonas citri ssp. citri.

This study was intended to characterize the chromosome segregation process of Xanthomonas citri ssp. citri (Xac) by investigating the functionality of the ParB factor encoded on its chromosome, and its requirement for cell viability and virulence. Using TAP tagging we show that ParB is expressed in Xac.

Recombinant expression and characterization of a cysteine peptidase from Xanthomonas citri subsp citri.

Xanthomonas citri subsp citri (Xac) is the bacterium responsible for citrus canker disease in citrus plants. The aim of this study was to describe the recombinant expression, purification, and characterization of a cysteine peptidase from Xac strain 306, which is a candidate for involvement in the pathogenicity of this bacterium. The gene was cloned and expressed in Pichia pastoris, and the cysteine peptidase was successfully expressed, secreted, and purified using affinity chromatography with a yield of approximately 10 mg/L.

Antibacterial activity of alkyl gallates against Xanthomonas citri subsp. citri.

The plant-pathogenic bacterium Xanthomonas citri subsp. citri is the causal agent of Asiatic citrus canker, a serious disease that affects all the cultivars of citrus in subtropical citrus-producing areas worldwide. There is no curative treatment for citrus canker; thus, the eradication of infected plants constitutes the only effective control of the spread of X.

Genetic Diversity of a Brazilian Strain Collection of Xanthomonas citri subsp. citri Based on the Type III Effector Protein Genes.

Exclusion and eradication or management based on an integrated approach with less susceptible varieties, copper-based bactericides, and windbreaks are the two main strategies used to prevent or control citrus canker. Field tolerance or resistance to citrus canker is not found in the most important commercial sweet orange cultivars, and pathogen-derived resistance has been developed and applied in different crops to obtain resistant genotypes to plant pathogens. We describe the development of DNA primers and probes based on the type III effector genes avrXacE1, avrXacE2, avrXacE3, avrBs2, pthA4, hpaF, and XAC3090 (leucine rich protein), and their application in the evaluation of the genetic diversity of the pathogen.

Subcellular localization of proteins labeled with GFP in Xanthomonas citri ssp. citri: targeting the division septum.

Xanthomonas citri ssp. citri (Xac) is the causal agent of citrus canker, an economically important disease that affects citrus worldwide. To initiate the characterization of essential biological processes of Xac, we constructed integrative plasmids for the ectopic expression of green fluorescent protein (GFP)-labeled proteins within this bacterium.

Optical fiber laser induced fluorescence spectroscopy as a citrus canker diagnostic.

Citrus canker is a serious disease caused by Xanthomonas citri subsp. citri bacteria, which infects citrus plants (Citrus spp.) leading to large economic losses in citrus production worldwide.

Detection of a New Bacterium Related to Xanthomonas fuscans subsp. aurantifolii Infecting Swingle Citrumelo in Brazil.

In March 2009, in a sweet orange orchard (Citrus sinensis) cv. Valencia grafted on Swingle citrumelo (C. paradisi Macf.

Ligation-mediated PCR, a fast and reliable technique for insertion sequence-based typing of Xanthomonas citri pv. citri.

Asiatic citrus canker, caused by Xanthomonas citri pv. citri, is a major disease threatening citrus crops throughout the world. The most common methods for strain differentiation of this pathogen are repetitive element sequence-based PCR (rep-PCR) and pulsed field gel electrophoresis (PFGE), using rare-cutting restriction enzyme analysis.

Detection of mechanical and disease stresses in citrus plants by fluorescence spectroscopy.

We have investigated the detection of mechanical and disease stresses in citrus plants (Citrus limonia [L.] Osbeck) using laser-induced fluorescence spectroscopy. Due to its economic importance we have chosen to investigate the citrus canker disease, which is caused by the Xanthomonas axonopodis pv.

Adult Citrus Leafminers (Phyllocnistis citrella) Are Not Efficient Vectors for Xanthomonas axonopodis pv. citri.

Interest in the interaction between the citrus leafminer (Phyllocnistis citrella) and citrus bacterial canker, caused by Xanthomonas axonopodis pv. citri, has increased as a greater incidence and severity of canker-diseased plants was observed in groves infested with the citrus leafminer. To determine whether adults of the citrus leafminer could act as vectors of citrus canker, we investigated two potential mechanisms for direct spread by leafminer adults using experimental microcosms.