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Wu F, Huang M, Fox EGP, Huang J, Cen Y, Deng X, Xu M. Preliminary Report on the Acquisition, Persistence, and Potential Transmission of Citrus tristeza virus by Diaphorina citri. INSECTS 2021; 12:insects12080735. [PMID: 34442301 PMCID: PMC8396932 DOI: 10.3390/insects12080735] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Revised: 08/10/2021] [Accepted: 08/12/2021] [Indexed: 11/29/2022]
Abstract
Simple Summary Citrus tristeza virus (CTV) is the causal agent of one of the most serious diseases of citrus and is described to be vectored by several aphid species. There have been no published reports of either acquisition or transmission of CTV by other insects, including phloem-feeding sternorrhynchans. The Asian citrus psyllid Diaphorina citri is an economically important pest since it is the vector of the bacterium associated with Huanglongbing (HLB) in citrus crops. We hereby reported the detection of CTV from field-collected D. citri and estimated the ability of these insects to acquire and transmit the virus. Under controlled conditions, D. citri nymphs were shown to acquire CTV from citrus trees, and the virus persisted in the psyllids for over 15 days. Controlled experiments also suggest that D. citri transmit CTV to healthy citrus plants but not to orange jasmine plants, a favorite host of D. citri. The results indicate D. citri is a potential vector of pathogens for two major citrus diseases: HLB and Citrus tristeza. Abstract Citrus tristeza virus (CTV) is one of the most important citrus tree viruses: a graft-transmissible virus that can be vectored by several aphid species. Diaphorina citri is the insect vector of “Candidatus Liberibacter spp.”, a bacterium associated with citrus Huanglongbing (HLB). However, no detailed description of the relationship between CTV and D. citri has been reported. In this study, D. citri adults collected from CTV-infected “Shatangju” mandarin, “Newhall” sweet orange, and “fingered citron” trees in different orchards yielded CTV-positive rates of 40%, 65%, and 95%, respectively, upon detection by conventional PCR. Illumina HiSeq sequencing followed by de novo assembly recovered the primary full CTV genome from the RNA of 30 D. citri adults sampled from CTV-positive citrus plants. Molting and adult emergence did not affect the presence or titers of CTV within the D. citri; however, the persistence of CTV in psyllids varied among different host plant species. Groups of 10 D. citri (from a population 85% CTV-positive) were shown to potentially transmit CTV to two citrus species, “Shatangju” mandarin and “Eureka” lemon, yielding 58.33% and 83.33% CTV-positive plants, respectively. No transmission of CTV to orange jasmine plants occurred. Thus, this study reports on the ability of D. citri to acquire and transmit CTV, making D. citri as a vector of two important citrus pathogens, warranting further attention and investigation.
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Affiliation(s)
- Fengnian Wu
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control/Citrus Huanglongbing Research Laboratory, South China Agricultural University, Guangzhou 510642, China; (F.W.); (M.H.); (J.H.); (Y.C.)
- School of Food Engineering and Biotechnology, Hanshan Normal University, Chaozhou 521041, China
| | - Mochi Huang
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control/Citrus Huanglongbing Research Laboratory, South China Agricultural University, Guangzhou 510642, China; (F.W.); (M.H.); (J.H.); (Y.C.)
| | - Eduardo G. P. Fox
- Instituto de Biofísica Carlos Chagas Filho, Centro de Ciências da Saúde, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-902, Brazil;
| | - Jiaquan Huang
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control/Citrus Huanglongbing Research Laboratory, South China Agricultural University, Guangzhou 510642, China; (F.W.); (M.H.); (J.H.); (Y.C.)
| | - Yijing Cen
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control/Citrus Huanglongbing Research Laboratory, South China Agricultural University, Guangzhou 510642, China; (F.W.); (M.H.); (J.H.); (Y.C.)
| | - Xiaoling Deng
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control/Citrus Huanglongbing Research Laboratory, South China Agricultural University, Guangzhou 510642, China; (F.W.); (M.H.); (J.H.); (Y.C.)
- Correspondence: (X.D.); (M.X.)
| | - Meirong Xu
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control/Citrus Huanglongbing Research Laboratory, South China Agricultural University, Guangzhou 510642, China; (F.W.); (M.H.); (J.H.); (Y.C.)
- Correspondence: (X.D.); (M.X.)
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Navas-Hermosilla E, Fiallo-Olivé E, Navas-Castillo J. Infectious Clones of Tomato Chlorosis Virus: Toward Increasing Efficiency by Introducing the Hepatitis Delta Virus Ribozyme. Front Microbiol 2021; 12:693457. [PMID: 34381428 PMCID: PMC8351799 DOI: 10.3389/fmicb.2021.693457] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2021] [Accepted: 06/04/2021] [Indexed: 11/13/2022] Open
Abstract
Tomato chlorosis virus (ToCV) is an emergent plant pathogen that causes a yellow leaf disorder in tomato and other solanaceous crops. ToCV is a positive-sense, single stranded (ss)RNA bipartite virus with long and flexuous virions belonging to the genus Crininivirus (family Closteroviridae). ToCV is phloem-limited, transmissible by whiteflies, and causes symptoms of interveinal chlorosis, bronzing, and necrosis in the lower leaves of tomato accompanied by a decline in vigor and reduction in fruit yield. The availability of infectious virus clones is a valuable tool for reverse genetic studies that has been long been hampered in the case of closterovirids due to their genome size and complexity. Here, attempts were made to improve the infectivity of the available agroinfectious cDNA ToCV clones (isolate AT80/99-IC from Spain) by adding the hepatitis delta virus (HDV) ribozyme fused to the 3′ end of both genome components, RNA1 and RNA2. The inclusion of the ribozyme generated a viral progeny with RNA1 3′ ends more similar to that present in the clone used for agroinoculation. Nevertheless, the obtained clones were not able to infect tomato plants by direct agroinoculation, like the original clones. However, the infectivity of the clones carrying the HDV ribozyme in Nicotiana benthamiana plants increased, on average, by two-fold compared with the previously available clones.
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Affiliation(s)
- Elisa Navas-Hermosilla
- Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora," Consejo Superior de Investigaciones Científicas, Universidad de Málaga (IHSM-CSIC-UMA), Algarrobo-Costa, Málaga, Spain
| | - Elvira Fiallo-Olivé
- Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora," Consejo Superior de Investigaciones Científicas, Universidad de Málaga (IHSM-CSIC-UMA), Algarrobo-Costa, Málaga, Spain
| | - Jesús Navas-Castillo
- Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora," Consejo Superior de Investigaciones Científicas, Universidad de Málaga (IHSM-CSIC-UMA), Algarrobo-Costa, Málaga, Spain
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Chen AYS, Peng JHC, Polek M, Tian T, Ludman M, Fátyol K, Ng JCK. Comparative analysis identifies amino acids critical for citrus tristeza virus (T36CA) encoded proteins involved in suppression of RNA silencing and differential systemic infection in two plant species. MOLECULAR PLANT PATHOLOGY 2021; 22:64-76. [PMID: 33118689 PMCID: PMC7749750 DOI: 10.1111/mpp.13008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Revised: 09/05/2020] [Accepted: 09/22/2020] [Indexed: 05/06/2023]
Abstract
Complementary (c)DNA clones corresponding to the full-length genome of T36CA (a Californian isolate of Citrus tristeza virus with the T36 genotype), which shares 99.1% identity with that of T36FL (a T36 isolate from Florida), were made into a vector system to express the green fluorescent protein (GFP). Agroinfiltration of two prototype T36CA-based vectors (pT36CA) to Nicotiana benthamiana plants resulted in local but not systemic GFP expression/viral infection. This contrasted with agroinfiltration of the T36FL-based vector (pT36FL), which resulted in both local and systemic GFP expression/viral infection. A prototype T36CA systemically infected RNA silencing-defective N. benthamiana lines, demonstrating that a genetic basis for its defective systemic infection was RNA silencing. We evaluated the in planta bioactivity of chimeric pT36CA-pT36FL constructs and the results suggested that nucleotide variants in several open reading frames of the prototype T36CA could be responsible for its defective systemic infection. A single amino acid substitution in each of two silencing suppressors, p20 (S107G) and p25 (G36D), of prototype T36CA facilitated its systemic infectivity in N. benthamiana (albeit with reduced titre relative to that of T36FL) but not in Citrus macrophylla plants. Enhanced virus accumulation and, remarkably, robust systemic infection of T36CA in N. benthamiana and C. macrophylla plants, respectively, required two additional amino acid substitutions engineered in p65 (N118S and S158L), a putative closterovirus movement protein. The availability of pT36CA provides a unique opportunity for comparative analysis to identify viral coding and noncoding nucleotides or sequences involved in functions that are vital for in planta infection.
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Affiliation(s)
- Angel Y. S. Chen
- Department of Microbiology and Plant PathologyUniversity of CaliforniaRiversideCaliforniaUSA
| | - James H. C. Peng
- Department of Microbiology and Plant PathologyUniversity of CaliforniaRiversideCaliforniaUSA
| | - MaryLou Polek
- National Clonal Germplasm Repository for Citrus & DatesUSDA ARSRiversideCaliforniaUSA
| | - Tongyan Tian
- California Department of Food and AgricultureSacramentoCaliforniaUSA
| | - Márta Ludman
- Agricultural Biotechnology InstituteNational Research and Innovation CenterHungary
| | - Károly Fátyol
- Agricultural Biotechnology InstituteNational Research and Innovation CenterHungary
| | - James C. K. Ng
- Department of Microbiology and Plant PathologyUniversity of CaliforniaRiversideCaliforniaUSA
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Cao M, Zhang S, Li M, Liu Y, Dong P, Li S, Kuang M, Li R, Zhou Y. Discovery of Four Novel Viruses Associated with Flower Yellowing Disease of Green Sichuan Pepper ( Zanthoxylum Armatum) by Virome Analysis. Viruses 2019; 11:v11080696. [PMID: 31370205 PMCID: PMC6723833 DOI: 10.3390/v11080696] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2019] [Revised: 07/28/2019] [Accepted: 07/28/2019] [Indexed: 01/21/2023] Open
Abstract
An emerging virus-like flower yellowing disease (FYD) of green Sichuan pepper (Zanthoxylum armatum v. novemfolius) has been recently reported. Four new RNA viruses were discovered in the FYD-affected plant by the virome analysis using high-throughput sequencing of transcriptome and small RNAs. The complete genomes were determined, and based on the sequence and phylogenetic analysis, they are considered to be new members of the genera Nepovirus (Secoviridae), Idaeovirus (unassigned), Enamovirus (Luteoviridae), and Nucleorhabdovirus (Rhabdoviridae), respectively. Therefore, the tentative names corresponding to these viruses are green Sichuan pepper-nepovirus (GSPNeV), -idaeovirus (GSPIV), -enamovirus (GSPEV), and -nucleorhabdovirus (GSPNuV). The viral population analysis showed that GSPNeV and GSPIV were dominant in the virome. The small RNA profiles of these viruses are in accordance with the typical virus-plant interaction model for Arabidopsis thaliana. Rapid and sensitive RT-PCR assays were developed for viral detection, and used to access the geographical distributions. The results revealed a correlation between GSPNeV and the FYD. The viruses pose potential threats to the normal production of green Sichuan pepper in the affected areas due to their natural transmission and wide spread in fields. Collectively, our results provide useful information regarding taxonomy, transmission and pathogenicity of the viruses as well as management of the FYD.
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Affiliation(s)
- Mengji Cao
- National Citrus Engineering Research Center, Citrus Research Institute, Southwest University, Chongqing 400712, China.
- Academy of Agricultural Sciences, Southwest University, Chongqing 400715, China.
| | - Song Zhang
- National Citrus Engineering Research Center, Citrus Research Institute, Southwest University, Chongqing 400712, China
- Academy of Agricultural Sciences, Southwest University, Chongqing 400715, China
| | - Min Li
- National Citrus Engineering Research Center, Citrus Research Institute, Southwest University, Chongqing 400712, China
- Academy of Agricultural Sciences, Southwest University, Chongqing 400715, China
| | - Yingjie Liu
- National Citrus Engineering Research Center, Citrus Research Institute, Southwest University, Chongqing 400712, China
- Academy of Agricultural Sciences, Southwest University, Chongqing 400715, China
| | - Peng Dong
- Chongqing Agricultural Technology Extension Station, Chongqing 401121, China
| | - Shanrong Li
- Chongqing Agricultural Technology Extension Station, Chongqing 401121, China
| | - Mi Kuang
- Chongqing Agricultural Technology Extension Station, Chongqing 401121, China
| | - Ruhui Li
- USDA-ARS, National Germplasm Resources Laboratory, Beltsville, MD 20705, USA
| | - Yan Zhou
- National Citrus Engineering Research Center, Citrus Research Institute, Southwest University, Chongqing 400712, China.
- Academy of Agricultural Sciences, Southwest University, Chongqing 400715, China.
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Mawassi M, Haviv S, Maslenin L. Amplification and Cloning of Large cDNA Fragments of the Citrus tristeza virus Genome. Methods Mol Biol 2019; 2015:151-161. [PMID: 31222702 DOI: 10.1007/978-1-4939-9558-5_11] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Citrus tristeza virus (CTV) is probably the most destructive viral pathogen of citrus. It causes chronic losses to commercial citrus production in all citrus-growing areas. The complete sequences of at least 42 genomes of different CTV strains have been obtained using different technologies including sequencing of multiple overlapped RT-PCR-amplified fragments with sizes of less than 4 kb, or from small viral RNA (svRNA), through next-generation high-throughput sequencing (NGS) technologies. The large size of CTV genome (>19.2 kb) makes it impractical to obtain and amplify full-length cDNA in a single step. The strategy of ligation of multiple cDNA fragments to assemble a full-length cDNA clone involves several serial cloning steps and sometimes subcloning phases using enzymatic digestion with restriction nucleases and ligation reactions. In this protocol, we describe a strategy to clone the entire genome of CTV obtained from two RT-PCR amplified products. These 5'- and 3'-genomic halves, which were designed to be overlapped in 15 nt in their 3'- and 5'-ends, respectively, were used as templates for further overlapped PCR to amplify the entire ~20 kb CTV genome. The resultant full cDNA PCR product was then inserted into pCAMBIA-binary vector.
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Affiliation(s)
- Munir Mawassi
- The S. Tolkowsky Laboratory, Department of Plant Pathology and Weed Research, The Volcani Center, Agricultural Research Organization, Bet Dagan, Israel.
| | - Sabrina Haviv
- The S. Tolkowsky Laboratory, Department of Plant Pathology and Weed Research, The Volcani Center, Agricultural Research Organization, Bet Dagan, Israel
| | - Ludmila Maslenin
- The S. Tolkowsky Laboratory, Department of Plant Pathology and Weed Research, The Volcani Center, Agricultural Research Organization, Bet Dagan, Israel
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