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Higgins SA, Igwe DO, Coradetti S, Ramsey JS, DeBlasio SL, Pitino M, Shatters RG, Niedz R, Fleites LA, Heck M. Plant-Derived, Nodule-Specific Cysteine-Rich Peptides as a Novel Source of Biopesticides for Controlling Citrus Greening Disease. PHYTOPATHOLOGY 2024; 114:971-981. [PMID: 38376984 DOI: 10.1094/phyto-09-23-0322-kc] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/22/2024]
Abstract
Nodule-specific cysteine-rich (NCR) peptides, encoded in the genome of the Mediterranean legume Medicago truncatula (barrelclover), are known to regulate plant-microbe interactions. A subset of computationally derived 20-mer peptide fragments from 182 NCR peptides was synthesized to identify those with activity against the unculturable vascular pathogen associated with citrus greening disease, 'Candidatus Liberibacter asiaticus' (CLas). Grounded in a design of experiments framework, we evaluated the peptides in a screening pipeline involving three distinct assays: a bacterial culture assay with Liberibacter crescens, a CLas-infected excised citrus leaf assay, and an assay to evaluate effects on bacterial acquisition by the nymphal stage of hemipteran vector Diaphorina citri. A subset of the 20-mer NCR peptide fragments inhibits both CLas growth in citrus leaves and CLas acquisition by D. citri. Two peptides induced higher levels of D. citri mortality. These findings reveal 20-mer NCR peptides as a new class of plant-derived biopesticide molecules to control citrus greening disease.
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Affiliation(s)
- Steven A Higgins
- Emerging Pests and Pathogens Research Unit, U.S. Department of Agriculture-Agricultural Research Service, Ithaca, NY 14853
| | - David O Igwe
- Plant Pathology and Plant Microbe Interactions Section, School of Integrative Plant Science, Cornell University, Ithaca, NY 14853
| | - Samuel Coradetti
- Emerging Pests and Pathogens Research Unit, U.S. Department of Agriculture-Agricultural Research Service, Ithaca, NY 14853
| | - John S Ramsey
- Emerging Pests and Pathogens Research Unit, U.S. Department of Agriculture-Agricultural Research Service, Ithaca, NY 14853
| | - Stacy L DeBlasio
- Emerging Pests and Pathogens Research Unit, U.S. Department of Agriculture-Agricultural Research Service, Ithaca, NY 14853
| | | | - Robert G Shatters
- U.S. Horticultural Research Laboratory, U.S. Department of Agriculture-Agricultural Research Service, Fort Pierce, FL 34945
| | - Randall Niedz
- U.S. Horticultural Research Laboratory, U.S. Department of Agriculture-Agricultural Research Service, Fort Pierce, FL 34945
| | - Laura A Fleites
- Emerging Pests and Pathogens Research Unit, U.S. Department of Agriculture-Agricultural Research Service, Ithaca, NY 14853
| | - Michelle Heck
- Emerging Pests and Pathogens Research Unit, U.S. Department of Agriculture-Agricultural Research Service, Ithaca, NY 14853
- Plant Pathology and Plant Microbe Interactions Section, School of Integrative Plant Science, Cornell University, Ithaca, NY 14853
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Kennedy JP, Wood K, Pitino M, Mandadi K, Igwe DO, Shatters RG, Widmer TL, Niedz R, Heck M. A Perspective on Current Therapeutic Molecule Screening Methods Against ' Candidatus Liberibacter asiaticus', the Presumed Causative Agent of Citrus Huanglongbing. PHYTOPATHOLOGY 2023; 113:1171-1179. [PMID: 36750555 DOI: 10.1094/phyto-12-22-0455-per] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Huanglongbing (HLB), referred to as citrus greening disease, is a bacterial disease impacting citrus production worldwide and is fatal to young trees and mature trees of certain varieties. In some areas, the disease is devastating the citrus industry. A successful solution to HLB will be measured in economics: citrus growers need treatments that improve tree health, fruit production, and most importantly, economic yield. The profitability of citrus groves is the ultimate metric that truly matters when searching for solutions to HLB. Scientific approaches used in the laboratory, greenhouse, or field trials are critical to the discovery of those solutions and to estimate the likelihood of success of a treatment aimed at commercialization. Researchers and the citrus industry use a number of proxy evaluations of potential HLB solutions; understanding the strengths and limitations of each assay, as well as how best to compare different assays, is critical for decision-making to advance therapies into field trials and commercialization. This perspective aims to help the reader compare and understand the limitations of different proxy evaluation systems based on the treatment and evaluation under consideration. The researcher must determine the suitability of one or more of these metrics to identify treatments and predict the usefulness of these treatments in having an eventual impact on citrus production and HLB mitigation. As therapies advance to field trials in the next few years, a reevaluation of these metrics will be useful to guide future research efforts on strategies to mitigate HLB and vascular bacterial pathogens in other perennial crops.
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Affiliation(s)
- John Paul Kennedy
- U.S. Horticultural Research Laboratory, U.S. Department of Agriculture-Agricultural Research Service, Fort Pierce, FL 34945
| | | | | | - Kranthi Mandadi
- Department of Plant Pathology and Microbiology, Texas A&M AgriLife Research and Extension Center, Weslaco, TX 78596
- Texas A&M AgriLife Institute for Advancing Health Through Agriculture, Texas A&M AgriLife, College Station, TX 77843
| | - David O Igwe
- Plant Pathology and Plant-Microbe Biology Section, School of Integrative Plant Science, Cornell University, Ithaca, NY 14853
| | - Robert G Shatters
- U.S. Horticultural Research Laboratory, U.S. Department of Agriculture-Agricultural Research Service, Fort Pierce, FL 34945
| | - Timothy L Widmer
- U.S. Department of Agriculture-Agricultural Research Service, Beltsville, MD 20705
| | - Randall Niedz
- U.S. Horticultural Research Laboratory, U.S. Department of Agriculture-Agricultural Research Service, Fort Pierce, FL 34945
| | - Michelle Heck
- Plant Pathology and Plant-Microbe Biology Section, School of Integrative Plant Science, Cornell University, Ithaca, NY 14853
- Emerging Pests and Pathogens Research Unit, U.S. Department of Agriculture-Agricultural Research Service, Ithaca, NY 14853
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Gao F, Wu B, Zou C, Bao Y, Li D, Yao W, Powell CA, Zhang M. Genetic Diversity of " Candidatus Liberibacter asiaticus" Based on Four Hypervariable Genomic Regions in China. Microbiol Spectr 2022; 10:e0262222. [PMID: 36409071 PMCID: PMC9769890 DOI: 10.1128/spectrum.02622-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Accepted: 10/17/2022] [Indexed: 11/23/2022] Open
Abstract
Huanglongbing (HLB; greening disease), caused by Candidatus Liberibacter asiaticus (CLas), is the most damaging citrus disease worldwide. The disease has spread throughout the citrus-producing regions of Guangxi, Guangdong, Fujian, and others in China. A total of 1,788 HLB-like symptomatic or asymptomatic samples were collected from the Guangxi and Fujian provinces of China to decipher the genetic diversity of CLas and its correlation with geographic region and host plant. The disease was the most severe in orange and the least in pomelo. CLas bacteria associated with the specific geographical and citrus variety infected more than 50% of the HLB-like symptomatic samples. We identified 6,286 minor variations by comparing 35 published CLas genomes and observed a highly heterogeneous variation distribution across the genome, including four highly diverse nonprophages and three prophage segments. Four hypervariable genomic regions (HGRs) were identified to determine the genetic diversity among the CLas isolates collected from Guangxi and Fujian, China. A phylogenetic tree constructed from four HGRs showed that 100 CLas strains could be separated into four distinct clades. Ten new strains with high variations of prophage regions were identified in the mandarin and tangerine grown in new plantation areas of Guangxi. Characterizing these HGR variations in the CLas bacteria may provide insight into their evolution and adaptation to host plants and insects. IMPORTANCE The hypervariable genomic regions derived from 35 published CLas genomes were used to decipher the genetic diversity of CLas strains and identify 10 new strains with high variations in prophage regions. Characterizing these variations in the CLas bacteria might provide insight into their evolution and adaptation to host plants and insects in China.
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Affiliation(s)
- Fanglan Gao
- State Key Laboratory for Conservation and Utilization of Sub-Tropical Bio-Agricultural Resources, Guangxi University, Guangxi, China
| | - Bo Wu
- School of Computing, Clemson University, Clemson, South Carolina, USA
| | - Chengwu Zou
- State Key Laboratory for Conservation and Utilization of Sub-Tropical Bio-Agricultural Resources, Guangxi University, Guangxi, China
| | - Yixue Bao
- State Key Laboratory for Conservation and Utilization of Sub-Tropical Bio-Agricultural Resources, Guangxi University, Guangxi, China
| | - Dean Li
- Fruit Experimental Station, Agricultural and Rural Department of Guangxi, Nanning, China
| | - Wei Yao
- State Key Laboratory for Conservation and Utilization of Sub-Tropical Bio-Agricultural Resources, Guangxi University, Guangxi, China
| | | | - Muqing Zhang
- State Key Laboratory for Conservation and Utilization of Sub-Tropical Bio-Agricultural Resources, Guangxi University, Guangxi, China
- IRREC, IFAS, University of Florida, Fort Pierce, Florida, USA
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da Graça JV, Cook G, Ajene IJ, Grout TG, Pietersen G, Roberts R, Bester R, Pretorius MC, Maree HJ. A Review of the ' Candidatus Liberibacter africanus' Citrus Pathosystem in Africa. PHYTOPATHOLOGY 2022; 112:44-54. [PMID: 34503351 DOI: 10.1094/phyto-07-21-0296-fi] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
It has been nearly 100 years since citrus growers in two distinct regions in the northern provinces of South Africa noticed unusual symptoms in their citrus trees, causing significant crop losses. They had no idea that these symptoms would later become part of an almost global pandemic of a disease called greening or huanglongbing (HLB). The rapid spread of the disease indicated that it might be caused by a transmissible pathogen, but it took >50 years to identify the causative agent as 'Candidatus Liberibacter africanus'. Recently, the disease appeared in more African countries, spreading by both infected planting material and Trioza erytreae. To date, five 'Ca. L. africanus' subspecies have been identified in various rutaceous species, with 'Ca. L. africanus subsp. clausenae' the only subspecies for which a biovar was detected in citrus. Efforts to detect and differentiate HLB-causing Liberibacter species are ongoing, and recent developments are discussed here. This review focuses on aspects of the African form of HLB, including its specific bacterial species and subspecies, its main insect vector, its geographic distribution, and current management strategies.
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Affiliation(s)
- John V da Graça
- Texas A&M University-Kingsville Citrus Center, Weslaco, TX, U.S.A
| | - Glynnis Cook
- Citrus Research International, Mbombela, South Africa
| | - Inusa J Ajene
- Department of Crop Protection, Ahmadu Bello University, Zaria, Nigeria
| | - Tim G Grout
- Citrus Research International, Mbombela, South Africa
| | - Gerhard Pietersen
- Department of Genetics, Stellenbosch University, Stellenbosch, South Africa
| | - Ronel Roberts
- Agricultural Research Council, Tropical and Subtropical Crops, Mbombela, South Africa
| | - Rachelle Bester
- Department of Genetics, Stellenbosch University, Stellenbosch, South Africa
- Citrus Research International, Stellenbosch, South Africa
| | | | - Hans J Maree
- Department of Genetics, Stellenbosch University, Stellenbosch, South Africa
- Citrus Research International, Stellenbosch, South Africa
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Lu J, Delatte H, Reynaud B, Beattie GAC, Holford P, Cen Y, Wang Y. Genome Sequence Resource of ' Candidatus Liberibacter asiaticus' from Diaphorina citri Kuwayama (Hemiptera: Liviidae) from La Réunion. PLANT DISEASE 2021; 105:1171-1173. [PMID: 33164668 DOI: 10.1094/pdis-09-20-1998-a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
'Candidatus Liberibacter asiaticus' is an insect-transmitted, phloem-restricted α-proteobacterium associated with huanglongbing. Here, we provide the whole genome sequence of 'Ca. L. asiaticus' strain ReuSP1 from its insect vector Diaphorina citri (Hemiptera: Liviidae) collected in La Réunion. The genome is composed of 1,230,064 bp and has a 36.5% G+C content. This study reports the first 'Ca. L. asiaticus' genome sequence from La Réunion, which will add to 'Ca. L. asiaticus' genome resources and help elucidate our understanding of the introduction pathway into La Réunion.
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Affiliation(s)
- Jinming Lu
- College of Forestry and Biotechnology, Zhejiang Agriculture & Forestry University, Lin'an, Zhejiang 311300, China
| | - Hélène Delatte
- CIRAD, UMR PVBMT CIRAD-Universitéde La Réunion, Pôle de Protection des Plantes, France
| | - Bernard Reynaud
- CIRAD, UMR PVBMT CIRAD-Universitéde La Réunion, Pôle de Protection des Plantes, France
| | - George A C Beattie
- School of Science, Western Sydney University, Penrith, NSW 2751, Australia
| | - Paul Holford
- School of Science, Western Sydney University, Penrith, NSW 2751, Australia
| | - Yijing Cen
- Key Laboratory of Bio-Pesticide Innovation and Application/Citrus Huanglongbing Research Laboratory, College of Plant Protection, South China Agricultural University, Guangzhou 510642, China
| | - Yanjing Wang
- College of Agriculture and Food Sciences, Zhejiang A&F University, Lin'an, Zhejiang 311300, China
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Ding F, Peng SA, Hartung JS. Enhanced Serologically Based Detection of Liberibacters Associated with Citrus Huanglongbing. PLANT DISEASE 2020; 104:1584-1588. [PMID: 32357120 DOI: 10.1094/pdis-12-19-2679-sc] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
'Candidatus Liberibacter spp.' are associated with the most devastating disease of citrus Huanglongbing (HLB). In previous work, we established an in situ tissue print method for the detection of 'Ca. L. asiaticus' (CLas) in sweet orange. We optimized the protocol by preincubation of the anti-Omp antibody with 5% (w/v) extract of healthy rough lemon. This simple process eliminated cross reactions between citrus and the antibody. The optimized protocol enhanced the application of the polyclonal antibody, and we demonstrate detection of CLas from all parts of the world, including isolates from Japan, Thailand, Vietnam, Pakistan, Saudi Arabia, Brazil, the United States, and a selection of strains from China representative of the diversity extant there. The assay also was used to detect four isolates of 'Ca. L. africanus' (CLaf) representative of the diversity present in South Africa. The corresponding outer membrane genes of representative isolates were cloned and sequenced. The coding sequences were highly conserved, and isolates of CLas and CLaf shared 53.8 to 55.9% identity between species at the amino acid level. The optimized protocol is efficient for recognition of both CLas and CLaf in phloem cells of different citrus tissues regardless of geographic origin of the HLB samples. The method is simple and scales well to match the urgent need for accurate, sensitive, and high-throughput screening of HLB bacteria, and may play an important role especially for plant inspection and quarantine programs.
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Affiliation(s)
- Fang Ding
- Hubei Key Laboratory of Plant Pathology, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070 P.R. China
- Key Laboratory of Horticultural Plant Biology (Huazhong Agricultural University), Ministry of Education, Wuhan, 430070 P.R. China
- United States Department of Agriculture, Agricultural Research Service Molecular Plant Pathology Laboratory, Beltsville, MD 20705, U.S.A
| | - Shu-Ang Peng
- Key Laboratory of Horticultural Plant Biology (Huazhong Agricultural University), Ministry of Education, Wuhan, 430070 P.R. China
| | - John S Hartung
- United States Department of Agriculture, Agricultural Research Service Molecular Plant Pathology Laboratory, Beltsville, MD 20705, U.S.A
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Paiva PEB, Cota T, Neto L, Soares C, Tomás JC, Duarte A. Water Vapor Pressure Deficit in Portugal and Implications for the Development of the Invasive African Citrus Psyllid Trioza erytreae. INSECTS 2020; 11:insects11040229. [PMID: 32272569 PMCID: PMC7240426 DOI: 10.3390/insects11040229] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Revised: 04/03/2020] [Accepted: 04/04/2020] [Indexed: 11/28/2022]
Abstract
African citrus psyllid (Trioza erytreae (Del Guercio)) is a vector insect of the bacterium Candidatus Liberibacter africanus, the putative causal agent of Huanglongbing, the most devastating citrus disease in the world. The insect was found on the island of Madeira in 1994 and in mainland Portugal in 2015. Present in the north and center of the country, it is a threat to Algarve, the main citrus-producing region. Trioza erytreae eggs and first instar nymphs are sensitive to the combination of high temperatures and low relative humidity. Daily maximum air temperature and minimum relative humidity data from 18 weather stations were used to calculate the water vapor pressure deficit (vpd) from 2004 to 2018 at various locations. Based on the mean vpd and the number of unfavorable days (vpd < 34.5 and vpd < 56 mbar) of two time periods (February to May and June to September), less favorable zones for T. erytreae were identified. The zones with thermal and water conditions like those observed in the Castelo Branco and Portalegre (Center), Beja (Alentejo), Alte, and Norinha (Algarve) stations showed climatic restrictions to the development of eggs and first instar nymphs of African citrus psyllid. Effective control measures, such as the introduction and mass release of Tamarixia dryi (Waterson), a specific parasitoid, and chemical control are necessary in favorable periods for T. erytreae development, such as in spring and in areas with limited or no climate restrictions.
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Affiliation(s)
- Paulo Eduardo Branco Paiva
- Instituto Federal de Educação, Ciência e Tecnologia do Triangulo Mineiro (IFTM), 38064-790 Uberaba, Brazil;
| | - Tânia Cota
- Divisão de Clima e Alterações Climáticas, Departamento de Meteorologia e Geofísica, Instituto Português do Mar e da Atmosfera I. P. (IPMA, IP), Rua C do Aeroporto, 1749-077 Lisboa, Portugal;
| | - Luís Neto
- MED - Mediterranean Institute for Agriculture, Environment and Development, University of Algarve, 8005-139 Faro, Portugal;
| | - Celestino Soares
- Direção Regional de Agricultura e Pescas do Algarve, Patacão, 8001-904 Faro, Portugal; (C.S.); (J.C.T.)
| | - José Carlos Tomás
- Direção Regional de Agricultura e Pescas do Algarve, Patacão, 8001-904 Faro, Portugal; (C.S.); (J.C.T.)
| | - Amílcar Duarte
- MED - Mediterranean Institute for Agriculture, Environment and Development, University of Algarve, 8005-139 Faro, Portugal;
- Correspondence:
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da Silva PA, Fassini CG, Sampaio LS, Dequigiovanni G, Zucchi MI, Wulff NA. Genetic Diversity of ' Candidatus Liberibacter asiaticus' Revealed by Short Tandem Repeats and Prophage Typing Indicates Population Homogeneity in Brazil. PHYTOPATHOLOGY 2019; 109:960-971. [PMID: 30694114 DOI: 10.1094/phyto-08-18-0295-r] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
'Candidatus Liberibacter asiaticus' is the most common huanglongbing-associated bacteria, being present in Asia, South, Central, and North America. Genomic approaches enabled sequencing of 'Ca. L. asiaticus' genomes, allowing for a broader assessment of its genetic variability with the application of polymerase chain reaction (PCR)-based tools such as microsatellite or short tandem repeat (STR) analysis. Although these tools contributed to a detailed analysis of strains from Japan, China, and the United States, Brazilian strains were analyzed in either too few samples with several STRs or in several strains with only a single microsatellite and a single PCR marker. We used 573 'Ca. L. asiaticus' strains, mainly collected from São Paulo State (SPS), in our genetic analyses, employing three STRs and several prophage PCR markers. STR revealed a homogeneous population regardless of sampling year or geographic regions of SPS. Thirty-eight haplotypes were recognized with a predominance of VNTR_005 higher than 10 repeats, with VNTR_002 and VNTR_077 containing 11 and 8 repeats, respectively. This haplotype is indicated as class HE, which comprised 80.28% of strains. Classes HA and HB, predominant in Florida, were not found. A new genomic organization in the junction of prophages SC2 and SC1 is prevalent in Brazilian strains, indicating gene rearrangement and a widespread occurrence of a type 1 prophage as well as the presence of a type 2-like prophage. Our results indicate that 'Ca. L. asiaticus' populations are homogeneous and harbor a new genomic organization in prophages type 1 and 2.
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Affiliation(s)
| | - Camila Giacomo Fassini
- 1 Departamento de Pesquisa & Desenvolvimento-Fundecitrus, Araraquara, SP, 14807-040, Brazil
| | - Laís Simões Sampaio
- 1 Departamento de Pesquisa & Desenvolvimento-Fundecitrus, Araraquara, SP, 14807-040, Brazil
| | - Gabriel Dequigiovanni
- 2 Agência Paulista de Tecnologia dos Agronegócios, Polo Regional Centro-Sul, Rodovia SP 127, km 30, Piracicaba, SP, 13400-970 Brazil; and
| | - Maria Imaculada Zucchi
- 2 Agência Paulista de Tecnologia dos Agronegócios, Polo Regional Centro-Sul, Rodovia SP 127, km 30, Piracicaba, SP, 13400-970 Brazil; and
| | - Nelson Arno Wulff
- 1 Departamento de Pesquisa & Desenvolvimento-Fundecitrus, Araraquara, SP, 14807-040, Brazil
- 3 PPG Biotecnologia, IQ/UNESP Araraquara, SP, 14800-060, Brazil
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Wulff NA, Fassini CG, Marques VV, Martins EC, Coletti DAB, Teixeira DDC, Sanches MM, Bové JM. Molecular Characterization and Detection of 16SrIII Group Phytoplasma Associated with Huanglongbing Symptoms. PHYTOPATHOLOGY 2019; 109:366-374. [PMID: 30226423 DOI: 10.1094/phyto-03-18-0081-r] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
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. Currently, 'Ca. L. asiaticus' is the predominant bacterium associated with HLB in citrus trees in São Paulo (SP) and Minas Gerais (MG) States, the major citrus-growing regions in Brazil. A phytoplasma from the 16SrIX group was associated with HLB symptoms in Brazil in 2007, in plants free of Liberibacter spp. In this report, HLB samples testing negative for 'Ca. L. asiaticus', 'Ca. L. americanus', and 16SrIX phytoplasma were infected with 16SrIII phytoplasmas. Coinfection with 'Ca. L. asiaticus' and 16SrIII was also found. The 16S ribosomal RNA (rRNA) gene sequences from 22 samples were obtained and sequenced, confirming that the 16SrIII group phytoplasma is associated with HLB symptoms in SP and MG States. Ten single-nucleotide polymorphisms (SNPs) were found in the 1,427-bp 16S rRNA gene sequences from 16SrIII phytoplasmas from citrus, whereas none was detected in 16S rRNA gene sequences among 16SrIX phytoplasma from citrus. Ribosomal protein (rp) rpsSrplVrpsC gene sequences were amplified with 16SrIII group-specific primers, sequenced from a subset of nine samples, and assembled into three groups based on eight SNPs. SNPs in 16S rRNA gene and rp gene sequences are common in 16SrIII phytoplasmas from other hosts and this phytoplasma group is widespread in South America. 16SrIII phytoplasmas highly related are commonly found in Melia azedarach, a widespread tree in Brazil and Argentina. The finding of a new phytoplasma associated with HLB symptoms belonging to the 16SrIII group reinforces the need to develop diagnostic tools to assess HLB-associated microbiomes.
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Affiliation(s)
- Nelson Arno Wulff
- 1 Departamento de Pesquisa & Desenvolvimento, Fundecitrus, Araraquara, SP, 14807-040 and PPG Biotecnologia, IQ/UNESP Araraquara, SP, 14800-060. Brazil
| | - Camila Giacomo Fassini
- 2 Departamento de Pesquisa & Desenvolvimento, Fundecitrus, Araraquara, SP, 14807-040, Brazil
| | - Viviani Vieira Marques
- 2 Departamento de Pesquisa & Desenvolvimento, Fundecitrus, Araraquara, SP, 14807-040, Brazil
| | - Elaine Cristina Martins
- 2 Departamento de Pesquisa & Desenvolvimento, Fundecitrus, Araraquara, SP, 14807-040, Brazil
| | | | - Diva do Carmo Teixeira
- 2 Departamento de Pesquisa & Desenvolvimento, Fundecitrus, Araraquara, SP, 14807-040, Brazil
| | | | - Joseph Marie Bové
- 2 Departamento de Pesquisa & Desenvolvimento, Fundecitrus, Araraquara, SP, 14807-040, Brazil
- 4 UMR 1332 Biologie du Fruit et Pathologie, Université de Bordeaux, INRA, 71 avenue Edouard Bourlaux, CS20032, F-33882 Villenave d'Ornon Cedex, France
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Choi CW, Hyun JW, Hwang RY, Powell CA. Loop-mediated Isothermal Amplification assay for Detection of Candidatus Liberibacter Asiaticus, a Causal Agent of Citrus Huanglongbing. THE PLANT PATHOLOGY JOURNAL 2018; 34:499-505. [PMID: 30588223 PMCID: PMC6305174 DOI: 10.5423/ppj.ft.10.2018.0212] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2018] [Revised: 11/14/2018] [Accepted: 11/14/2018] [Indexed: 06/01/2023]
Abstract
Huanglongbing (HLB, Citrus greening disease) is one of the most devastating diseases that threaten citrus production worldwide. Although HLB presents systemically, low titer and uneven distribution of these bacteria within infected plants can make reliable detection difficult. It was known loop-mediated isothermal amplification (LAMP) method has the advantages of being highly specific, rapid, efficient, and laborsaving for detection of plant pathogens. We developed a new LAMP method targeting gene contained tandem repeat for more rapid and sensitive detection of Candidatus Liberibacter asiaticus (CLas), putative causal agent of the citrus huanglongbing. This new LAMP method was 10 folds more sensitive than conventional PCR in detecting the HLB pathogen and similar to that of real-time PCR in visual detection assay by adding SYBR Green I to mixture and 1% agarose gel electrophoresis. Positive reactions were achieved in reaction temperature 57, 60 and 62°C but not 65°C. Although this LAMP method was not more sensitive than real-time PCR, it does not require a thermocycler for amplification or agarose gel electrophoresis for resolution. Thus, we expect that this LAMP method shows strong promise as a reliable, rapid, and cost-effective method of detecting the CLas in citrus and can be applied for rapid diagnosis is needed.
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Affiliation(s)
- Cheol Woo Choi
- Citrus Research Institute, National Institute of Horticultural and Herbal Science, R.D.A. Jeju 63607,
Korea
| | - Jae Wook Hyun
- Citrus Research Institute, National Institute of Horticultural and Herbal Science, R.D.A. Jeju 63607,
Korea
| | - Rok Yeon Hwang
- Citrus Research Institute, National Institute of Horticultural and Herbal Science, R.D.A. Jeju 63607,
Korea
| | - Charles A Powell
- University of Florida, Institute of Food and Agricultural Sciences, Indian River Research and Education Center, 2199 South Rock Road, Fort Pierce, FL 34945,
USA
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Roberts R, Cook G, Grout TG, Khamis F, Rwomushana I, Nderitu PW, Seguni Z, Materu CL, Steyn C, Pietersen G, Ekesi S, le Roux HF. Resolution of the Identity of 'Candidatus Liberibacter' Species From Huanglongbing-Affected Citrus in East Africa. PLANT DISEASE 2017; 101:1481-1488. [PMID: 30678595 DOI: 10.1094/pdis-11-16-1655-re] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
'Candidatus Liberibacter asiaticus', the bacterium associated with citrus Huanglongbing (HLB), was reported from Uganda and tentatively from Tanzania, posing a threat to citriculture in Africa. Two surveys of citrus expressing typical HLB symptoms were conducted in Uganda, Kenya, and Tanzania to verify reports of 'Ca. L. asiaticus' and to assess the overall threat of HLB to eastern and southern African citrus production. Samples were analyzed for the presence of 'Candidatus Liberibacter' species by real-time PCR and partial sequencing of three housekeeping genes, 16S rDNA, rplJ, and omp. 'Ca. L. africanus', the bacterium historically associated with HLB symptoms in Africa, was detected in several samples. However, samples positive in real-time PCR for 'Ca. L. asiaticus' were shown not to contain 'Ca. L. asiaticus' by sequencing. Sequences obtained from these samples were analogous to 'Ca. L. africanus subsp. clausenae', identified from an indigenous Rutaceae species in South Africa, and not to 'Ca. L. asiaticus'. Results indicate a nontarget amplification of the real-time assay and suggest that previous reports of 'Ca. L. asiaticus' from Uganda and Tanzania may be mis-identifications of 'Ca. L. africanus subsp. clausenae'. This subspecies was additionally detected in individual Diaphorina citri and Trioza erytreae specimens recovered from collection sites. This is the first report of 'Ca. L. africanus subsp. clausenae' infecting citrus and being associated with HLB symptoms in this host.
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Affiliation(s)
- Ronel Roberts
- Plant Microbiology Division, Agricultural Research Council-Plant Protection Research, Pretoria 0001, South Africa
| | - Glynnis Cook
- Citrus Research International, Nelspruit 1200, South Africa
| | - Tim G Grout
- Citrus Research International, Nelspruit 1200, South Africa
| | - Fathiya Khamis
- International Centre of Insect Physiology and Ecology, Nairobi, Kenya
| | - Ivan Rwomushana
- International Centre of Insect Physiology and Ecology, Nairobi, Kenya
| | | | - Zuberi Seguni
- Mikocheni Agricultural Research Institute, Dar es Salaam, Tanzania
| | | | - Chanel Steyn
- Citrus Research International, Nelspruit 1200, South Africa
| | - Gerhard Pietersen
- Plant Microbiology Division, Agricultural Research Council-Plant Protection Research, Pretoria 0001, South Africa
| | - Sunday Ekesi
- International Centre of Insect Physiology and Ecology, Nairobi, Kenya
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12
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Roberts R, Pietersen G. A novel subspecies of 'Candidatus Liberibacter africanus' found on native Teclea gerrardii (Family: Rutaceae) from South Africa. Antonie van Leeuwenhoek 2016; 110:437-444. [PMID: 27830472 DOI: 10.1007/s10482-016-0799-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2016] [Accepted: 11/01/2016] [Indexed: 01/18/2023]
Abstract
The phloem limited bacterium 'Candidatus Liberibacter africanus' is associated with citrus greening disease in South Africa. This bacterium has been identified solely from commercial citrus in Africa and the Mascarene islands, and its origin may lie within an indigenous rutaceous host from Africa. Recently, in determining whether alternative hosts of Laf exist amongst the indigenous rutaceous hosts of its triozid vector, Trioza erytreae, three novel subspecies of Laf were identified i.e. 'Candidatus Liberibacter africanus subsp. clausenae', 'Candidatus Liberibacter africanus subsp. vepridis' and 'Candidatus Liberibacter africanus subsp. zanthoxyli' in addition to the formerly identified 'Candidatus Liberibacter africanus subsp. capensis'. The current study expands upon the range of indigenous rutaceous tree species tested for liberibacters closely related to Laf and its subspecies. A collection of 121 samples of Teclea and Oricia species were sampled from Oribi Gorge and Umtamvunu nature reserves in KwaZulu Natal. Total DNA was extracted and the presence of liberibacters from these samples determined using a generic liberibacter TaqMan real-time PCR assay. Liberibacters from positive samples were further characterised through amplification and sequencing of the 16S rRNA, outer-membrane protein (omp) and 50S ribosomal protein L10 (rplJ) genes. A single Teclea gerrardii specimen tested positive for a liberibacter and, through phylogenetic analyses of the three genes sequenced, was shown to be unique, albeit closely related to 'Ca. L. africanus' and 'Ca. L. africanus subsp. zanthoxyli'. We propose that this newly identified liberibacter be named 'Candidatus Liberibacter africanus subsp. tecleae'.
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Affiliation(s)
- Ronel Roberts
- Department of Microbiology and Plant Pathology, Forestry and Agricultural Biotechnology Institute, University of Pretoria, Pretoria, 0002, South Africa.,Plant Microbiology Division, Agricultural Research Council-Plant Protection Research, Private Bag X134, Pretoria, 0001, South Africa
| | - Gerhard Pietersen
- Department of Microbiology and Plant Pathology, Forestry and Agricultural Biotechnology Institute, University of Pretoria, Pretoria, 0002, South Africa. .,Plant Microbiology Division, Agricultural Research Council-Plant Protection Research, Private Bag X134, Pretoria, 0001, South Africa.
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Arredondo Valdés R, Delgado Ortiz JC, Beltrán Beache M, Anguiano Cabello J, Cerna Chávez E, Rodríguez Pagaza Y, Ochoa Fuentes YM. A review of techniques for detecting Huanglongbing (greening) in citrus. Can J Microbiol 2016; 62:803-811. [PMID: 27590666 DOI: 10.1139/cjm-2016-0022] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Huanglongbing (HLB) is the most destructive disease of citrus worldwide. Monitoring of health and detection of diseases in trees is critical for sustainable agriculture. HLB symptoms are virtually the same wherever the disease occurs. The disease is caused by Candidatus Liberibacter spp., vectored by the psyllids Diaphorina citri Kuwayama and Trioza erytreae. Electron microscopy was the first technique used for HLB detection. Nowadays, scientists are working on the development of new techniques for a rapid HLB detection, as there is no sensor commercially accessible for real-time assessment of health conditions in trees. Currently, the most widely used mechanism for monitoring HLB is exploration, which is an expensive, labor-intensive, and time-consuming process. Molecular techniques such as polymerase chain reaction are used for the identification of HLB disease, which requires detailed sampling and processing procedures. Furthermore, investigations are ongoing in spectroscopic and imaging techniques, profiling of plant volatile organic compounds, and isothermal amplification. This study recognizes the need for developing a rapid, cost-effective, and reliable health-monitoring sensor that would facilitate advancements in HLB disease detection. This paper compares the benefits and limitations of these potential methods for HLB detection.
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Affiliation(s)
- Roberto Arredondo Valdés
- a Universidad Autónoma Agraria Antonio Narro, Department of Agricultural Parasitology, Buenavista, Saltillo, Coahuila, C.P. 25315, Mexico
| | - Juan C Delgado Ortiz
- a Universidad Autónoma Agraria Antonio Narro, Department of Agricultural Parasitology, Buenavista, Saltillo, Coahuila, C.P. 25315, Mexico
| | - Mariana Beltrán Beache
- a Universidad Autónoma Agraria Antonio Narro, Department of Agricultural Parasitology, Buenavista, Saltillo, Coahuila, C.P. 25315, Mexico
| | - Julia Anguiano Cabello
- a Universidad Autónoma Agraria Antonio Narro, Department of Agricultural Parasitology, Buenavista, Saltillo, Coahuila, C.P. 25315, Mexico
| | - Ernesto Cerna Chávez
- a Universidad Autónoma Agraria Antonio Narro, Department of Agricultural Parasitology, Buenavista, Saltillo, Coahuila, C.P. 25315, Mexico
| | - Yolanda Rodríguez Pagaza
- b Catedrática CONACYT-Universidad Autónoma Agraria Antonio Narro, Department of Agricultural Parasitology, Buenavista, Saltillo, Coahuila, C.P. 25315, Mexico
| | - Yisa M Ochoa Fuentes
- a Universidad Autónoma Agraria Antonio Narro, Department of Agricultural Parasitology, Buenavista, Saltillo, Coahuila, C.P. 25315, Mexico
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Pontes JGM, Ohashi WY, Brasil AJM, Filgueiras PR, Espíndola APDM, Silva JS, Poppi RJ, Coletta-Filho HD, Tasic L. Metabolomics by NMR Spectroscopy in Plant Disease diagnostic: Huanglongbing as a Case Study. ChemistrySelect 2016. [DOI: 10.1002/slct.201600064] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Affiliation(s)
- João Guilherme M. Pontes
- Departamento de Química Orgânica; Instituto de Química; UNICAMP; Campinas-SP P. O. Box 6154 13083-970 Brazil
| | - William Y. Ohashi
- Departamento de Química Orgânica; Instituto de Química; UNICAMP; Campinas-SP P. O. Box 6154 13083-970 Brazil
| | - Antonio J. M. Brasil
- Departamento de Química Orgânica; Instituto de Química; UNICAMP; Campinas-SP P. O. Box 6154 13083-970 Brazil
| | - Paulo R. Filgueiras
- Departamento de Química Analítica; Instituto de Química; UNICAMP; Campinas-SP P. O. Box 6154 13083-970 Brazil
| | - Ana Paula D. M. Espíndola
- Departamento de Química Orgânica; Instituto de Química; UNICAMP; Campinas-SP P. O. Box 6154 13083-970 Brazil
| | - Jaqueline S. Silva
- Departamento de Química Orgânica; Instituto de Química; UNICAMP; Campinas-SP P. O. Box 6154 13083-970 Brazil
| | - Ronei J. Poppi
- Departamento de Química Analítica; Instituto de Química; UNICAMP; Campinas-SP P. O. Box 6154 13083-970 Brazil
| | - Helvécio D. Coletta-Filho
- Instituto Agronômico de Campinas; Centro de Citricultura Sylvio Moreira; Cordeirópolis-SP, km 158 P. O. Box 04 13490-970 Brazil
| | - Ljubica Tasic
- Departamento de Química Orgânica; Instituto de Química; UNICAMP; Campinas-SP P. O. Box 6154 13083-970 Brazil
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Hilf ME, Lewis RS. Transmission and Propagation of 'Candidatus Liberibacter asiaticus' by Grafting with Individual Citrus Leaves. PHYTOPATHOLOGY 2016; 106:452-458. [PMID: 26807818 DOI: 10.1094/phyto-09-15-0221-r] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Huanglongbing (HLB) is a chronic, progressive decline disease in citrus associated with a systemic infection by the bacterium 'Candidatus Liberibacter asiaticus'. Transmission of the bacterium in the field is by the Asian citrus psyllid, Diaphorina citri Kuwayama. Experimental propagation of 'Ca. L. asiaticus' is done primarily by grafting pieces of bud wood from an infected plant. To produce a small-scale model system for investigation of pathogen biology, we investigated grafting single leaves from infected citrus plants as sources of inoculum for propagation of the bacterium. In total, 162 plants ranging in age from 3 to 18 months were grafted. Grafting with intact asymptomatic and HLB-symptomatic leaves resulted in 61 of 78 (78%) and 35 of 41 (85%) of the plants infected with 'Ca. L. asiaticus', respectively. Inoculum consisting of the leaf petiole only or only an inoculum tissue remnant under the bark of the receptor tree resulted in 6 of 12 (50%) and 7 of 31 (23%) infected trees, respectively. Real-time polymerase chain reaction (qPCR) assays verified the infection in plants, a majority of which developed the foliar blotchy mottle symptom considered diagnostic for HLB, while some plants also displayed the stunted, chlorotic shoots for which the disease is named. The qPCR data together with the symptoms displayed demonstrated that individual leaves from infected trees can serve as effective inoculum sources for transmission and propagation of 'Ca. L. asiaticus' via grafting.
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Affiliation(s)
- Mark E Hilf
- United States Department of Agriculture-Agricultural Research Service, 2001 S. Rock Road, Fort Pierce, FL
| | - Reid S Lewis
- United States Department of Agriculture-Agricultural Research Service, 2001 S. Rock Road, Fort Pierce, FL
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Lin H, Pietersen G, Han C, Read DA, Lou B, Gupta G, Civerolo EL. Complete Genome Sequence of "Candidatus Liberibacter africanus," a Bacterium Associated with Citrus Huanglongbing. GENOME ANNOUNCEMENTS 2015; 3:e00733-15. [PMID: 26184931 PMCID: PMC4505119 DOI: 10.1128/genomea.00733-15] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 05/27/2015] [Accepted: 06/15/2015] [Indexed: 11/20/2022]
Abstract
We report here the complete genome sequence of "Candidatus Liberibacter africanus" strain PTSAPSY. The 1,192,232-bp genome with 34.5% G+C content comprises 1,017 open reading frames, 44 tRNAs, and three complete rRNAs in a circular chromosome.
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Affiliation(s)
- Hong Lin
- USDA-ARS San Joaquin Valley Agricultural Sciences Center, Parlier, California, USA
| | | | - Cliff Han
- Los Alamos National Laboratory, Los Alamos, New Mexico, USA
| | | | - Binghai Lou
- Guangxi Citrus Research Institute, Guilin, China
| | - Goutam Gupta
- Los Alamos National Laboratory, Los Alamos, New Mexico, USA
| | - Edwin L Civerolo
- USDA-ARS San Joaquin Valley Agricultural Sciences Center, Parlier, California, USA
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Roberts R, Steenkamp ET, Pietersen G. Three novel lineages of ‘Candidatus Liberibacter africanus’ associated with native rutaceous hosts of Trioza erytreae in South Africa. Int J Syst Evol Microbiol 2015; 65:723-731. [DOI: 10.1099/ijs.0.069864-0] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Greening disease of citrus in South Africa is associated with ‘Candidatus Liberibacter africanus’ (Laf), a phloem-limited bacterium vectored by the sap-sucking insect Trioza erytreae (Triozidae). Despite the implementation of control strategies, this disease remains problematic, suggesting the existence of reservoir hosts to Laf. The current study aimed to identify such hosts. Samples from 234 trees of Clausena anisata, 289 trees of Vepris lanceolata and 231 trees of Zanthoxylum capense were collected throughout the natural distribution of these trees in South Africa. Total DNA was extracted from samples and tested for the presence of liberibacters by a generic Liberibacter TaqMan real-time PCR assay. Liberibacters present in positive samples were characterized by amplifying and sequencing rplJ, omp and 16S rRNA gene regions. The identity of tree host species from which liberibacter sequences were obtained was verified by sequencing host rbcL genes. Of the trees tested, 33 specimens of Clausena, 17 specimens of Vepris and 10 specimens of Zanthoxylum tested positive for liberibacter. None of the samples contained typical citrus-infecting Laf sequences. Phylogenetic analysis of 16S rRNA gene sequences indicated that the liberibacters obtained from Vepris and Clausena had 16S rRNA gene sequences identical to that of ‘Candidatus Liberibacter africanus subsp. capensis’ (LafC), whereas those from Zanthoxylum species grouped separately. Phylogenetic analysis of the rplJ and omp gene regions revealed unique clusters for liberibacters associated with each tree species. We propose the following names for these novel liberibacters: ‘Candidatus Liberibacter africanus subsp. clausenae’ (LafCl), ‘Candidatus Liberibacter africanus subsp. vepridis’ (LafV) and ‘Candidatus Liberibacter africanus subsp. zanthoxyli’ (LafZ). This study did not find any natural hosts of Laf associated with greening of citrus. While native citrus relatives were shown to be infected with Laf-related liberibacters, nucleotide sequence data suggest that these are not alternative sources of Laf to citrus orchards, per se.
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Affiliation(s)
- Ronel Roberts
- Division of Microbiology and Plant Pathology, ARC-Plant Protection Research Institute, Pretoria, South Africa
- Department of Microbiology and Plant Pathology, Forestry and Agricultural Biotechnology Institute, University of Pretoria, Pretoria, South Africa
| | - Emma T. Steenkamp
- Department of Microbiology and Plant Pathology, Forestry and Agricultural Biotechnology Institute, University of Pretoria, Pretoria, South Africa
| | - Gerhard Pietersen
- Division of Microbiology and Plant Pathology, ARC-Plant Protection Research Institute, Pretoria, South Africa
- Department of Microbiology and Plant Pathology, Forestry and Agricultural Biotechnology Institute, University of Pretoria, Pretoria, South Africa
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18
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Munyaneza JE, Sengoda VG, Buchman JL, Fisher TW. Effects of Temperature on 'Candidatus Liberibacter solanacearum' and Zebra Chip Potato Disease Symptom Development. PLANT DISEASE 2012; 96:18-23. [PMID: 30731847 DOI: 10.1094/pdis-03-11-0185] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Temperature has been shown to have a significant effect on development of liberibacter species associated with citrus Huanglongbing disease. 'Candidatus Liberibacter africanus' and 'Ca. L. americanus' are both heat sensitive, whereas 'Ca. L. asiaticus' is heat tolerant. The recently described 'Ca. L. solanacearum' is associated with zebra chip (ZC), a newly emerging and economically important disease of potato worldwide. This psyllid-transmitted liberibacter species severely affects several other solanaceous crops and carrot. Experiments were conducted to evaluate effects of temperature on development of 'Ca. L. solanacearum' and ZC disease. Potato plants were inoculated with 'Ca. L. solanacearum' by briefly exposing them to liberibacter-infective potato psyllids at various temperatures under laboratory conditions. Following insect exposure, the plants were maintained at selected temperature regimes in growth chambers, monitored for ZC symptom development, and later tested for liberibacter by polymerase chain reaction to confirm infection. Results indicated that temperatures below 17°C appear to slow development of 'Ca. L. solanacearum' and ZC symptoms, whereas temperatures above 32°C are detrimental to this liberibacter. Compared to Huanglongbing liberibacters, 'Ca. L. solanacearum' appears heat sensitive. The sensitivity of this bacterium and its insect vector to temperature may partially explain incidence, severity, and distribution of ZC in affected regions.
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Affiliation(s)
- Joseph E Munyaneza
- USDA-ARS, Yakima Agricultural Research Laboratory, 5230 Konnowac Pass Road, Wapato, WA 98951
| | - Venkatesan G Sengoda
- USDA-ARS, Yakima Agricultural Research Laboratory, 5230 Konnowac Pass Road, Wapato, WA 98951
| | - Jeremy L Buchman
- USDA-ARS, Yakima Agricultural Research Laboratory, 5230 Konnowac Pass Road, Wapato, WA 98951
| | - Tonja W Fisher
- USDA-ARS, Yakima Agricultural Research Laboratory, 5230 Konnowac Pass Road, Wapato, WA 98951
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