CHEMICAL & ENGINEERING NEWS 31/03/21 Groups challenge EPA approval of streptomycin use on citrus. A coalition of environmental and farmworker groups is suing the US Environmental Protection Agency for allowing use of the medically important antibiotic streptomycin on citrus.
The groups are concerned that widespread use of streptomycin as a pesticide will worsen the problem of antibiotic-resistant bacteria. The EPA approved the use of streptomycin to combat citrus greening and citrus canker during the final days of the Trump administration. The agency says that those diseases have caused $1.75 billion in losses to US citrus growers over the past decade. The petitioners claim that the EPA failed to demonstrate that use of streptomycin on citrus would not pose unreasonable risks to human health and the environment.
They also claim that the agency did not adequately address the risks to endangered species. MOLECULAR PLANT PATHOLOGY - 2018 - Recent advances in the understanding of Xanthomonas citri ssp. citri pathogenesis and citrus canker disease management. MOLECULAR PLANT PATHOLOGY - 2004 - Xanthomonas axonopodis pv. citri: factors affecting successful eradication of citrus canker. JOURNAL OF PLANT PATHOLOGY 25/01/20 New insights into the resistance of four citrus genotypes to Xanthomonas citri subsp. citri. JOURNAL OF PHYTOPATHOLOGY 18/11/19 Efficacy of different copper compounds in the control of Xanthomonas citri subsp. citri pathotypes A and A. Citrus canker disease is one of the most devastating diseases that attacks citrus, especially limes in the Southern parts of Iran, and is caused by Xanthomonas citri subsp. citri (Xcc).
The efficacy of several formulations of copper compounds including Bordeaux mixture, copper oxychloride and copper sulphate in controlling Xcc in Key lime was estimated in vitro and in planta using artificial inoculation. Specific primers were used to detect copper‐resistant genes copA, copB and copL in 30 isolates of Xcc. The copA and copL genes were present in all isolates, and copB was detected only in 6 strains. In this study, we observed a very good in vitro growth inhibition activity of copper compounds against Xcc pathotype A. S14 strain (pathotype A*) was the sole isolate that grew on media amended with 2/4 mM of Bordeaux mixture, copper oxychloride and copper sulphate.
CROP & PASTURE SCIENCE 01/04/20 Variation in the aggressiveness of Xanthomonas citri subsp. citri pathotypes A and A* on three Citrus species, and epiphytic growth on some citrus weeds. Al-Saleh MA, Widyawan A, Saleh AA, Ibrahim YE (2014) Distribution and pathotypes identification of Xanthomonas citri subsp. citri recovered from south western region of Saudi Arabia.
African Journal of Microbiological Research8, 673–679. | Distribution and pathotypes identification of Xanthomonas citri subsp. citri recovered from south western region of Saudi Arabia.Crossref | GoogleScholarGoogle Scholar | Behlau F, Scandelai L, Junior G, Lanza F (2017) Soluble and insoluble copper formulations and metallic copper rate for control of citrus canker on sweet orange trees.
Crop Protection94, 185–191.| Soluble and insoluble copper formulations and metallic copper rate for control of citrus canker on sweet orange trees.Crossref | GoogleScholarGoogle Scholar | Brunings AM, Gabriel DW (2003) Xanthomonas citri: breaking the surface. BSPP 17/01/20 First report of Xanthomonas phaseoli pv. phaseoli and Xanthomonas citri pv. fuscans causing common bacterial blight of bean in Belgium.
New Disease Reports (2020) 41, 6. [ Get pdf (838 KB)
BMC GENOMICS 09/09/19 Origin and diversification of Xanthomonas citri subsp. citri pathotypes revealed by inclusive phylogenomic, dating, and biogeographic analyses. INTECH 23/08/19 Biological Control of Citrus Canker: New Approach for Disease Control. 1.
Introduction The steady increase in global overpopulation has forced the agricultural producer to introduce environmentally aggressive practices (e.g., undiscriminating use of pesticides and chemical fertilizers), in order to respond to the rising request of cultivated crops for food. The growing breach between supply and request and the negative impact on the environment have stimulated researchers to develop alternative strategies, pursuing to promote a sustainable agriculture. The interactions between plants and their associated microorganisms have generated a huge interest. MOLECULAR PLANT PATHOLOGY - 2018 - Recent advances in the understanding of Xanthomonas citri ssp. citri pathogenesis and citrus canker disease management. ENVIRONMENTAL MICROBIOLOGY 28/02/18 Xanthomonas citri T6SS mediates resistance to Dictyostelium predation and is regulated by an ECF σ factor and cognate Ser/Thr kinase.
Plant‐associated bacteria of the genus Xanthomonas cause disease in a wide range of economically important crops.
However, their ability to persist in the environment is still poorly understood. Predation by amoebas represents a major selective pressure to bacterial populations in the environment. In this study, we show that the X. citri type 6 secretion system (T6SS) promotes resistance to predation by the soil amoeba Dictyostelium discoideum. We found that an extracytoplasmic function (ECF) sigma factor (EcfK) is required for induction of T6SS genes during interaction with Dictyostelium. EcfK homologues are found in several environmental bacteria in association with a gene encoding a eukaryotic‐like Ser/Thr kinase (pknS). PHYS_ORG 25/05/18 Researchers discover mechanism behind citrus canker bacteria's defense system for predators. Xanthomonas citri, the bacterium that causes citrus canker, a disease responsible for major damage to lemon and orange groves in worldwide scale, has a veritable arsenal of weapons to overcome constant competition with other bacterial species and ward off natural predators such as amoebae.
Despite the fact that citrus canker have already caused significant economic losses, X. citri's ability to persist in the environment is still poorly understood. However, a new study performed in Brazil perfects scientific understanding on the gene expression regulating the bacteria's defense mechanism against natural predators—which might subsidize the development of strategies to fight the pest on infected plants.
The study revealed that the mechanism resides in a protein secretion system known as the T6SS (type VI secretion system) present in several species of bacterium but only now characterized in X. citri. LETTERS IN APPLIED MICROBIOLOGY 31/03/18 Terrestrial and marine Antarctic fungi extracts active against Xanthomonas citri subsp. citri. This study aims to obtain secondary metabolites extracts from filamentous fungi isolated from soil and marine sediments from Antarctica and assess its potential antibacterial activity on Xanthomonas citri subsp. citri, the agent of citrus canker.
Metabolites production was conducted in Malt 2% broth at 15°C for 20 days after which intracellular and extracellular extracts were obtained. The extracts were evaluated by cell viability assays through Resazurin Microtitre Assay. From 158 fungal extracts, 33 hampered bacterial growth in vitro. The average inhibition of the extracts obtained from terrestrial (soil) and marine (sediments) fungi was 94 and 97% respectively. These inhibition values were close to the average of 90% cell death for the positive control. Significance and Impact of the Study. PHYS_ORG 14/06/18 Antarctic fungi found to be effective against citrus canker. A research team at the São Paulo State University's Bioscience Institute (IB-UNESP) in Rio Claro, Brazil, has identified 29 fungi with proven action against Xanthomonas citri, a bacterium responsible for citrus canker, an endemic disease in all citrus-producing countries.
The origin of the fungi is surprising. They were isolated from samples of soil and marine sediment collected in Antarctica. "These fungi live in isolated conditions and proliferate under inhospitable conditions including low temperatures and high levels of ultraviolet radiation," says Daiane Cristina Sass, a professor at UNESP who heads a project engaged in a search for microorganisms that produce compounds with antibacterial action for use in agriculture. "How have they adapted to survive in an environment so hostile to life? We wanted to see if they produced molecules with unique structures that protected them from infections and might therefore be capable of antibacterial action.
" Vasantrao Naik Marathwada Agricultural University - 2012 - Thèse en ligne : Studies on citrus canker caused by xanthomonas axonopodis pv. citri. Indian National Agricultural Research System - 2015 - Thèse en ligne : VARIABILITY IN Xanthomonas axonopodis pv. citri (Hasse) Vauterin AN INCITANT OF CITRUS CANKER ON ACID LIME. GEP - MARS 2018 - Occurrence of Canker Caused by Xanthomonas axonopodis pv. citri on Pummelo (Citrus maxima (Burm.) Merr.) Cultivar. Tabtimsiam in Nakhon Si Thammarat Province, Thailand and Screening Fungicides, Antibiotics and Antagonistic Bacteria again. 1.
Introduction Thailand is the land of plenty of tropical fruit crop. The most popular is rambutan, pummelo, mangosteen and durian. GOVERNMENT OF WESTERN AUSTRALIA - 2018 - Preventing the spread of citrus canker in Western Australia. New Phytol. 2017 May; 214(3): Risk‐based management of invading plant disease. Plant Biotechnol J. 2017 December; 15(12): Engineering canker‐resistant plants through CRISPR/Cas9‐targeted editing of the susceptibility gene CsLOB1 promoter in citrus.
Genome Announc. 2017 September; 5(36): First Complete Genome Sequences of Xanthomonas citri pv. vignicola Strains CFBP7111, CFBP7112, and CFBP7113 Obtained Using Long-Read Technology. BMC Genomics. 2018; 19: 16. Pacbio sequencing of copper-tolerant Xanthomonas citri reveals presence of a chimeric plasmid structure and provides insights into reassortment and shuffling of transcription activator-like effectors among X. citri strains. Int.J.Curr.Microbiol.App.Sci (2017)6(8): Studies on Variability, Identification of Xanthomonas axonopodis pv. punicae Isolates and Screening of Gamma (γ) Irradiated Seed Derived Progenies and Germplasms of Pomegranate. Indian National Agricultural Research System - NOV 2017 - Thèse en ligne : Detection,characterization,and management of Xanthomonas axonopodis pv.citri causing canker disease in citrus. AEM 22/02/17 Ecological and Evolutionary Insights into Xanthomonas citri Pathovar Diversity. INTERNATIONAL JOURNAL OF AGRONOMY 30/04/16 Assessment and molecular characterization of citrus canker causing pathotypes.
Advances in Zoology and Botany Vol. 6(1), pp. 26 - 30 2018 Induction of Resistance against Citrus Canker through Chemicals and Plant Activators. Advances in Zoology and Botany Vol. 6(1), pp. 26 - 30 DOI: 10.13189/azb.2018.060103 Reprint (PDF) (109Kb) Waqas Ahmed Khan 1, Muhammad Atiq 1,*, Shahbaz Talib Sahi 1, Awais Ahmed Khan 2, Shafqat Ali 1, Muhammad Younas 3, Yasir Ali 1, Muhammad Rizwan Bashir 4, Muhammad Sajid 51 Department of Plant Pathology, University of Agriculture, Faisalabad, Pakistan2 University College of Agriculture, University of Sargodha, Sargodha, Pakistan3 Directorate General Agriculture (E & AR), Agriculture, Pakistan4 Oil Seed Research Institute, Ayub Agriculture Research Institute (AARI), Faisalabad, Pakistan5 Department of plant Pathology, Bahuddin Zakaryya University, Multan, Pakistan KEYWORDS Citrus Canker, Copper Hydroxide, Naphthalene Acetic Acid, Resistance, Salicylic Acid, Xanthomonas axonopodis Cite this paper Waqas Ahmed Khan , Muhammad Atiq , Shahbaz Talib Sahi , Awais Ahmed Khan , Shafqat Ali , Muhammad Younas , Yasir Ali , Muhammad Rizwan Bashir , Muhammad Sajid (2018).
Genome Announc. 2017 Jul; 5(28): Complete Genome Sequences of Three Xanthomonas citri Strains from Texas. AMERICAN JOURNAL OF PLANT SCIENCES - 2017 - Phytohormone-Induced Resistance against Xanthomonas axonopodis PV. citri in Citrus aurantifolia. UFL_EDU 20/11/17 Présentation : Citrus Canker. Plant Pathol J. 2017 Oct; 33(5): 441–449. Management of Citrus Canker in Argentina, a Success Story. AUSTRALASIAN PLANT DIS 25/02/15 First record of citrus canker, caused by Xanthomonas citri subsp. citri in Solomon Islands. EFSA 20/06/17 Citrus junos as a host of citrus bacterial canker. Abstract Following a request from the European Commission, the European Food Safety Authority (EFSA) Plant Health (PLH) Panel analysed a dossier submitted by the Japanese authorities in order to clarify the host status of Citrus junos with regard to Xanthomonas citri pv. citri and Xanthomonas citri pv. aurantifolii, causal agents of citrus bacterial canker, and to indicate whether C. junos fruit could represent a pathway for the introduction of citrus bacterial canker into the European Union.
The Commission has proposed, through an implementing regulation, changes to the annexes to Directive 2000/29/EC on plant health. These changes will considerably weaken checks on citrus imports. Among other things, citrus fruits intended for industrial processing will be subject to fewer checks than fresh produce from countries affected by citrus canker and citrus black spot. This measure has provoked serious concern in the sector, above all given the large number of cases of black spot disease being detected in citrus fruit from third countries, and owing to the serious damage that the sector could suffer if the disease were to spread to European plantations. It also seems surprising, bearing in mind the agreement that was recently reached on the new plant health regulation, aimed at stepping up the fight against the spread of diseases from third countries.
Can the Commission explain why it plans to reduce checks? 2BLADES FOUNDATION - OCT 2016 - Citrus Canker - Multipronged approach to combat citrus disease. "We most definitely need a non-copper control. Copper builds up in the soil and makes a very toxic growing environment that lasts for decades. I don't think I can over-stress the problem that canker is causing in Florida groves. Although it's still very early in the season, to date I have had more fruit drop from canker than I have from HLB [citrus greening]. " —Bobby Barben, grower The challenge. PARLEMENT EUROPEEN - Réponse à question E-004975-16 Proposed changes to the annexes to Directive 2000/29/EC on plant health ( citrus canker and citrus black spot)
PARLEMENT EUROPEEN - Réponse à question E-004975-16 Proposed changes to the annexes to Directive 2000/29/EC on plant health ( citrus canker and citrus black spot) Appl Environ Microbiol. 2014 Oct; 80(20): 6266–6279. Genomic Insights into the Evolutionary Origin of Xanthomonas axonopodis pv. citri and Its Ecological Relatives. TROPICAL PLANT PATHOLOGY 22/02/16 Prevalence of race 18 of Xanthomonas citri subsp. malvacearum on cotton in Brazil. Mol Plant Microbe Interact. 2016 Feb;29(2):132-42. Reduced Susceptibility to Xanthomonas citri in Transgenic Citrus Expressing the FLS2 Receptor From Nicotiana benthamiana. Crop Protection Volume 74, August 2015, Induced resistance in sweet orange against Xanthomonas citri subsp. citri by hexanoic acid. PLOS 23/04/13 A Novel Two-Component Response Regulator Links rpf with Biofilm Formation and Virulence of Xanthomonas axonopodis pv. citri. Abstract. LSU AG CENTER 07/02/13 New citrus disease found in New Orleans (citrus canker)
AUSTRALIAN GOVERNMENT - 2016 - National Diagnostic Protocol for Asiatic Citrus Canker, Xanthomonas citri subsp. citri. Pak. J. Agri., Agril. Engg., Vet. Sci., 2014, 30 (2): 187-194 PATHOGENIC VARIABILITY AMONG DIFFERENT ISOALTES OF XANTHOMONAS AXONOPODIS PV. CITRI. Journal of Pure and Applied Microbiology (Impact Factor: 0.07). 12/2012 Microbial, Biochemical, Pathogenicity and Molecular Characterization of Xanthomonas axonopodis pv. punicae from Pomegranate. PLOS 04/06/14 A MLVA Genotyping Scheme for Global Surveillance of the Citrus Pathogen Xanthomonas citri pv. citri Suggests a Worldwide Geographical Expansion of a Single Genetic Lineage. The Journal of Plant Pathology 08/2014; 114(114):177-187. Prevalence of canker on seedlings of citrus (Citrus spp.) in selected areas of Bangladesh and its management. Trop. plant pathol. vol.39 no.6 Brasília Nov./Dec. 2014 Favorable conditions for Xanthomonas axonopodis infection in Eucalyptus spp.
Scientific Opinion of the PLH Panel: Xanthomonas axonopodis pv. phaseoli and Xanthomonas fuscans subsp. fuscans pest categorisation. FRONTIERS IN MICROBIOLOGY 23/04/13 Citrus tristeza virus: evolution of complex and varied genotypic groups. JOURNAL OF BACTERIOLOGY - 2013 - Genome sequence of Xanthomonas axonopodis pv. punicae strain LMG 859. FAPESP - Programme de recherche 2013-2015. The Journal of Animal & Plant Sciences, 23(1): 2013 GENETIC RESPONSE OF CITRUS GERMPLASM AGAINST CITRUS LEAF MINER. Workshop on Interdisciplinary Plant Science 16/12/13 Présentation : Functional genomics approaches in Xanthomonascitri/citrus pa.
Central California Tristeza Eradication Agency – 2013 - Présentation : Citrus Pest Detection Program. ARS USDA - 2013 - Présentation : Presence of virulent strains of Citrus tristeza virus (CTV) in California. BMC Microbiology 2013, 13:186 Insights into xanthomonas axonopodis pv. citri biofilm through proteomics. Sci. agric. (Piracicaba, Braz.) vol.70 no.2 Piracicaba Mar./Apr. 2013 Evaluation of the protective capacity of new mild Citrus t. Evaluation of the protective capacity of new mild Citrus tristeza virus (CTV) isolates selected for a preimmunization program Carlos Alexandre Zanutto*; Maria Júlia Corazza; William Mário de Carvalho Nunes; Gerd Walter Müller UEM - Depto. de Agronomia, Núcleo de Pesquisa em Biotecnologia Aplicada, Av. Colombo, 5790 - 87020-900 - Maringá, PR - Brasil The use of tolerant rootstocks and preimmunization has satisfactorily controlled losses associated with the Citrus tristeza virus (CTV).
Several researchers have shown that CTV mild isolates that are selected in the same region where they are used are superior to isolates obtained from other areas. Keywords: SSCP, RFLP, cross-protection, citrus Introduction In the past 90 years, citrus tristeza has been considered one of the most important citrus diseases worldwide (Souza and Müller, 2006). GROWING PRODUCE 12/07/13 Citrus Canker Detected In Louisiana - Disease discovery is first U.S. find outside of Florida. USDA’s Animal and Plant Health Inspection Service (APHIS) has confirmed the identification of Xanthomonas axonopodis pv. citri, the bacterial causal agent of citrus canker, from citrus leaf samples collected from two trees in City Park, New Orleans, Orleans Parish, Louisiana.
African Journal of Biotechnology Vol. 9 (54), pp. 9092-9095, 29 December, 2010 Molecular and biochemical characterization of Xan. International Rules for Seed Testing - 2012 - Detection of Xanthomonas axonopodis pv. phaseoli and Xanthomonas axonopodis pv. ph. Mol Plant Pathol. 2012 Aug;13(6):614-29. Top 10 plant pathogenic bacteria in molecular plant pathology. FORMATEX - 2010 - Mechanisms of infection used by Xanthomonas axonopodis pv. citri in citrus canker disease.