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Adegbola RO, Ponvert ND, Brown JK. Genetic Variability Among U.S.-Sentinel Cotton Plot Cotton Leafroll Dwarf Virus and Globally Available Reference Isolates Based on ORF0 Diversity. PLANT DISEASE 2024; 108:1799-1811. [PMID: 38277653 DOI: 10.1094/pdis-02-23-0243-re] [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: 01/28/2024]
Abstract
The aphid-transmitted polerovirus, cotton leafroll dwarf virus (CLRDV), first characterized from symptomatic cotton plants in South America, has been identified in commercial cotton plantings in the United States. Here, the CLRDV intraspecific diversity was investigated by comparative sequence analysis of the most divergent CLRDV coding region, ORF0/P0. Bayesian analysis of ORF0 sequences for U.S. and reference populations resolved three well-supported sister clades comprising one U.S. and two South American lineages. Principal component analysis (PCA) identified seven statistically supported intraspecific populations. The Bayesian phylogeny and PCA dendrogram-inferred relationships were congruent. Population analysis of ORF0 sequences indicated most lineages have evolved under negative selection, albeit certain sites/isolates evolved under positive selection. Both U.S. and South American isolates exhibited extensive ORF0 diversity. At least two U.S. invasion foci were associated with their founder populations in Alabama-Georgia and eastern Texas. The Alabama-Georgia founder is implicated as the source of recent widespread expansion and establishment of secondary disease foci throughout the southeastern-central United States. Based on the geographically restricted distribution, spread of another extant Texas population appeared impeded by a population bottleneck. Extant CLRDV isolates represent several putative introductions potentially associated with catastrophic weather events dispersing viruliferous cotton aphids of unknown origin(s).
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Affiliation(s)
| | | | - Judith K Brown
- School of Plant Sciences, University of Arizona, Tucson, AZ 85721
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2
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Spivey WW, Williamson Z, Seiter J, Abrahamian P, Wang H, Greene J, Cieniewicz E. Analysis of Cotton Leafroll Dwarf Virus P0 Gene Sequences from South Carolina Reveals Low Variability Among Isolates. PLANT DISEASE 2023; 107:2613-2619. [PMID: 36825312 DOI: 10.1094/pdis-10-22-2514-sr] [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
Cotton leafroll dwarf virus (CLRDV) is emerging across the major cotton-producing states of the southern United States. Because it was detected in nearly all cotton-producing states within a few years of its initial detection in the United States, the spread of the virus has apparently occurred rapidly. In this study spanning three growing seasons in South Carolina, we collected CLRDV isolates from symptomatic and asymptomatic cotton plants in 10 counties. The genomic region encoding P0, the viral suppressor of RNA silencing, was sequenced and compared among CLRDV isolates. Low variability among CLRDV P0 sequences from South Carolina isolates with similarities to other United States isolates was revealed by amino acid sequence alignment and phylogenetic analysis. Low variability among South Carolina isolates was also confirmed by sequencing a subset of eight near-complete genomes of CLRDV isolates. Although sequence variability was low among South Carolina isolates, this data should be taken in the context of all United States isolates, for which diversity may be higher than initially expected. Sequences gathered in this study add to the body of knowledge on CLRDV diversity in the United States.
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Affiliation(s)
- William W Spivey
- Department of Plant and Environmental Sciences, Clemson University, Clemson, SC 29634
| | | | - Jacob Seiter
- Department of Entomology and Plant Pathology, North Carolina State University, Raleigh, NC 27695
| | - Peter Abrahamian
- USDA-APHIS-PPQ Science and Technology, Plant Pathogen Confirmatory Diagnostic Laboratory, Laurel, MD 20708
| | - Hehe Wang
- Department of Plant and Environmental Sciences, Clemson University, Edisto Research and Education Center, Blackville, SC 29817
| | - Jeremy Greene
- Department of Plant and Environmental Sciences, Clemson University, Edisto Research and Education Center, Blackville, SC 29817
| | - Elizabeth Cieniewicz
- Department of Plant and Environmental Sciences, Clemson University, Clemson, SC 29634
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Mahas JW, Mahas JB, Ray C, Kesheimer A, Steury TD, Conzemius SR, Crow W, Gore J, Greene JK, Kennedy GG, Kerns D, Malone S, Paula-Moraes S, Roberts P, Stewart SD, Taylor S, Toews M, Jacobson AL. The Spatiotemporal Distribution, Abundance, and Seasonal Dynamics of Cotton-Infesting Aphids in the Southern U.S. INSECTS 2023; 14:639. [PMID: 37504645 PMCID: PMC10380445 DOI: 10.3390/insects14070639] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2023] [Revised: 07/04/2023] [Accepted: 07/13/2023] [Indexed: 07/29/2023]
Abstract
Cotton leafroll dwarf virus (CLRDV) is an emerging aphid-borne pathogen infecting cotton, Gossypium hirsutum L., in the southern United States (U.S.). The cotton aphid, Aphis gossypii Glover, infests cotton annually and is the only known vector to transmit CLRDV to cotton. Seven other species have been reported to feed on, but not often infest, cotton: Protaphis middletonii Thomas, Aphis craccivora Koch, Aphis fabae Scopoli, Macrosiphum euphorbiae Thomas, Myzus persicae Sulzer, Rhopalosiphum rufiabdominale Sasaki, and Smynthurodes betae Westwood. These seven have not been studied in cotton, but due to their potential epidemiological importance, an understanding of the intra- and inter-annual variations of these species is needed. In 2020 and 2021, aphids were monitored from North Carolina to Texas using pan traps around cotton fields. All of the species known to infest cotton, excluding A. fabae, were detected in this study. Protaphis middletonii and A. gossypii were the most abundant species identified. The five other species of aphids captured were consistently low throughout the study and, with the exception of R. rufiabdominale, were not detected at all locations. The abundance, distribution, and seasonal dynamics of cotton-infesting aphids across the southern U.S. are discussed.
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Affiliation(s)
- John W Mahas
- Department of Entomology and Plant Pathology, Auburn University, 301 Funchess Hall, Auburn, AL 36849, USA
| | - Jessica B Mahas
- Department of Entomology and Plant Pathology, Auburn University, 301 Funchess Hall, Auburn, AL 36849, USA
| | - Charles Ray
- Department of Entomology and Plant Pathology, Auburn University, 301 Funchess Hall, Auburn, AL 36849, USA
| | - Adam Kesheimer
- Department of Entomology and Plant Pathology, Auburn University, 301 Funchess Hall, Auburn, AL 36849, USA
| | - Todd D Steury
- College of Forestry, Wildlife and Environment, Auburn University, 602 Duncan Drive, Auburn, AL 36849, USA
| | - Sophia R Conzemius
- Edisto Research and Education Center, Department of Plant and Environmental Sciences, Clemson University, Blackville, SC 29817, USA
| | - Whitney Crow
- Delta Research and Extension Center, Mississippi State University, Stoneville, MS 39762, USA
| | - Jeffrey Gore
- Delta Research and Extension Center, Mississippi State University, Stoneville, MS 39762, USA
| | - Jeremy K Greene
- Edisto Research and Education Center, Department of Plant and Environmental Sciences, Clemson University, Blackville, SC 29817, USA
| | - George G Kennedy
- Department of Entomology and Plant Pathology, North Carolina State University, 3210 Ligon St., Raleigh, NC 27695, USA
| | - David Kerns
- Department of Entomology, Texas A&M University, College Station, TX 77843, USA
| | - Sean Malone
- Virginia Tech, Tidewater Agricultural Research and Extension Center, Suffolk, VA 23437, USA
| | - Silvana Paula-Moraes
- West Florida Research and Education Center, Department of Entomology and Nematology, University of Florida, Jay, FL 32565, USA
| | - Phillip Roberts
- Department of Entomology, University of Georgia, 2360 Rainwater Rd., Tifton, GA 31793, USA
| | - Scott D Stewart
- Department of Entomology and Plant Pathology, University of Tennessee, Knoxville, TN 37996, USA
| | - Sally Taylor
- Virginia Tech, Tidewater Agricultural Research and Extension Center, Suffolk, VA 23437, USA
| | - Michael Toews
- Department of Entomology, University of Georgia, 2360 Rainwater Rd., Tifton, GA 31793, USA
| | - Alana L Jacobson
- Department of Entomology and Plant Pathology, Auburn University, 301 Funchess Hall, Auburn, AL 36849, USA
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Edula SR, Bag S, Milner H, Kumar M, Suassuna ND, Chee PW, Kemerait RC, Hand LC, Snider JL, Srinivasan R, Roberts PM. Cotton leafroll dwarf disease: An enigmatic viral disease in cotton. MOLECULAR PLANT PATHOLOGY 2023; 24:513-526. [PMID: 37038256 PMCID: PMC10189767 DOI: 10.1111/mpp.13335] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Revised: 03/18/2023] [Accepted: 03/21/2023] [Indexed: 05/18/2023]
Abstract
TAXONOMY Cotton leafroll dwarf virus (CLRDV) is a member of the genus Polerovirus, family Solemoviridae. Geographical Distribution: CLRDV is present in most cotton-producing regions worldwide, prominently in North and South America. PHYSICAL PROPERTIES The virion is a nonenveloped icosahedron with T = 3 icosahedral lattice symmetry that has a diameter of 26-34 nm and comprises 180 molecules of the capsid protein. The CsCl buoyant density of the virion is 1.39-1.42 g/cm3 and S20w is 115-127S. Genome: CLRDV shares genomic features with other poleroviruses; its genome consists of monopartite, single-stranded, positive-sense RNA, is approximately 5.7-5.8 kb in length, and is composed of seven open reading frames (ORFs) with an intergenic region between ORF2 and ORF3a. TRANSMISSION CLRDV is transmitted efficiently by the cotton aphid (Aphis gossypii Glover) in a circulative and nonpropagative manner. Host: CLRDV has a limited host range. Cotton is the primary host, and it has also been detected in different weeds in and around commercial cotton fields in Georgia, USA. SYMPTOMS Cotton plants infected early in the growth stage exhibit reddening or bronzing of foliage, maroon stems and petioles, and drooping. Plants infected in later growth stages exhibit intense green foliage with leaf rugosity, moderate to severe stunting, shortened internodes, and increased boll shedding/abortion, resulting in poor boll retention. These symptoms are variable and are probably influenced by the time of infection, plant growth stage, varieties, soil health, and geographical location. CLRDV is also often detected in symptomless plants. CONTROL Vector management with the application of chemical insecticides is ineffective. Some host plant varieties grown in South America are resistant, but all varieties grown in the United States are susceptible. Integrated disease management strategies, including weed management and removal of volunteer stalks, could reduce the abundance of virus inoculum in the field.
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Affiliation(s)
| | - Sudeep Bag
- Department of Plant PathologyUniversity of GeorgiaTiftonGeorgiaUSA
| | - Hayley Milner
- Department of Plant PathologyUniversity of GeorgiaTiftonGeorgiaUSA
| | - Manish Kumar
- Department of Plant PathologyUniversity of GeorgiaTiftonGeorgiaUSA
| | | | - Peng W. Chee
- Institute of Plant, Breeding, Genetics, and GenomicsUniversity of GeorgiaTiftonGeorgiaUSA
| | | | - Lavesta C. Hand
- Department of Crop and Soil SciencesUniversity of GeorgiaTiftonGeorgiaUSA
| | - John L. Snider
- Department of Crop and Soil SciencesUniversity of GeorgiaTiftonGeorgiaUSA
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O'Hara FM, Liu Z, Davis JA, Swale DR. Catalyzing systemic movement of inward rectifier potassium channel inhibitors for antifeedant activity against the cotton aphid, Aphis gossypii (Glover). PEST MANAGEMENT SCIENCE 2023; 79:194-205. [PMID: 36116013 DOI: 10.1002/ps.7188] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2022] [Revised: 08/26/2022] [Accepted: 09/18/2022] [Indexed: 06/15/2023]
Abstract
BACKGROUND The cotton aphid, Aphis gossypii Glover (Hemiptera: Aphididae), is a destructive agricultural pest, capable of photosynthate removal and plant virus transmission. Therefore, we aimed to test the antifeedant properties of small-molecule inhibitors of inward rectifier potassium (Kir) channels expressed in insect salivary glands and develop an approach for enabling systemic movement of lipophilic Kir inhibitors. RESULTS Two Kir channel inhibitors, VU041 and VU730, reduced the secretory activity of the aphid salivary glands by 3.3-fold and foliar applications of VU041 and VU730 significantly (P < 0.05) increased the time to first probe, total probe duration, and nearly eliminated phloem salivation and ingestion. Next, we aimed to facilitate systemic movement of VU041 and VU730 through evaluation of a novel natural product based solubilizer containing rubusoside that was isolated from Chinese sweet leaf (Rubus suavissimus) plants. A single lower leaf was treated with Kir inhibitor soluble liquid (KI-SL) and systemic movement throughout the plant was verified via toxicity bioassays and changes to feeding behavior through the electrical penetration graph (EPG) technique. EPG data indicate KI-SL significantly reduced ability to reach E1 (phloem salivation) and E2 (phloem ingestion) waveforms and altered plant probing behavior when compared to the untreated control. High-performance liquid chromatography (HPLC) analysis indicated the presence of VU041 and VU730 in the upper leaf tissue of these plants. Together, these data provide strong support that incorporation of rubusoside with Kir inhibitors enhanced translaminar and translocation movement through the plant tissue. CONCLUSION These data further support hemipteran Kir channels as a target to prevent feeding and induce toxicity. Further, these studies highlight a novel delivery approach for generating plant systemic activity of lipophilic insecticides. © 2022 Society of Chemical Industry.
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Affiliation(s)
- Flinn M O'Hara
- Department of Entomology, Louisiana State University AgCenter, Baton Rouge, LA, USA
| | - Zhijun Liu
- School of Renewable Natural Resources, Louisiana State University AgCenter, Baton Rouge, LA, USA
| | - Jeffrey A Davis
- Department of Entomology, Louisiana State University AgCenter, Baton Rouge, LA, USA
| | - Daniel R Swale
- Department of Entomology, Louisiana State University AgCenter, Baton Rouge, LA, USA
- Department of Entomology and Nematology, Emerging Pathogens Institute, University of Florida, Gainesville, FL, USA
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O'Hara FM, Davis JA, Swale DR. Profile of commercialized aphicides on the survivorship and feeding behavior of the cotton aphid, Aphis gossypii. PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY 2022; 186:105174. [PMID: 35973765 DOI: 10.1016/j.pestbp.2022.105174] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Revised: 07/05/2022] [Accepted: 07/07/2022] [Indexed: 06/15/2023]
Abstract
The cotton aphid, Aphis gossypii Glover (Hemiptera: Aphididae), is one of the most destructive agricultural pests due to photosynthate removal and horizontal transmission of plant viruses. Horizontal transmission of plant viruses by aphids occurs during distinct feeding behavioral events, such as probing for non-persistent viruses or phloem feeding for persistent viruses. We employed toxicity bioassays and electrical penetration graph (EPG) methodology to compare toxicity and quantify changes to feeding behavior and toxicity of A. gossypii after exposure to commercialized aphicides. Commercialized aphicides containing flupyradifurone, sulfoxaflor, thiamethoxam, thiamethoxam + lambda cyhalothrin, and bifenthrin induced >90% aphid mortality within 4 h of exposure. Flupyradifurone was the most acutely toxic aphicide studied with an LT50 of 8.9 min after exposure, which was approximately 3-fold lower than bifenthrin and thiamethoxam + lambda cyhalothrin. This was supported by our EPG results that showed a significant reduction in the proportion of aphids that continued to probe on cotton 4 h after exposure to flonicamid, thiamethoxam, flupyradifurone, bifenthrin, and thiamethoxam + lambda cyhalothrin. The commercialized aphicides containing spirotetramat, flonicamid, thiamethoxam, flupyradifurone, bifenthrin, sulfoxaflor, and pymetrozine significantly (P < 0.05) decreased the time to first probe when compared to the untreated control. Lastly, E1 (phloem salivation) and E2 (phloem ingestion) waveforms were significantly (P < 0.05) reduced for flupyradifurone, flonicamid, thiamethoxam, sulfoxaflor, and thiamethoxam. These data provide a comparative study for the development of new aphicides aiming to induce acute lethality and reduce aphid transmission of plant viruses.
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Affiliation(s)
- Flinn M O'Hara
- Department of Entomology, Louisiana State University AgCenter, Baton Rouge, LA 70803, United States of America
| | - Jeffrey A Davis
- Department of Entomology, Louisiana State University AgCenter, Baton Rouge, LA 70803, United States of America
| | - Daniel R Swale
- Department of Entomology, Louisiana State University AgCenter, Baton Rouge, LA 70803, United States of America.
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Tarazi R, Vaslin MFS. The Viral Threat in Cotton: How New and Emerging Technologies Accelerate Virus Identification and Virus Resistance Breeding. FRONTIERS IN PLANT SCIENCE 2022; 13:851939. [PMID: 35449884 PMCID: PMC9016188 DOI: 10.3389/fpls.2022.851939] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Accepted: 03/07/2022] [Indexed: 05/12/2023]
Abstract
Cotton (Gossypium spp. L., Malvaceae) is the world's largest source of natural fibers. Virus outbreaks are fast and economically devasting regarding cotton. Identifying new viruses is challenging as virus symptoms usually mimic nutrient deficiency, insect damage, and auxin herbicide injury. Traditional viral identification methods are costly and time-consuming. Developing new resistant cotton lines to face viral threats has been slow until the recent use of molecular virology, genomics, new breeding techniques (NBT), remote sensing, and artificial intelligence (AI). This perspective article demonstrates rapid, sensitive, and cheap technologies to identify viral diseases and propose their use for virus resistance breeding.
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Affiliation(s)
- Roberto Tarazi
- Plant Molecular Virology Laboratory, Department of Virology, Microbiology Institute, Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, Brazil
- Programa de Pós-graduação em Biotecnologia e Bioprocessos da UFRJ, Rio de Janeiro, Brazil
| | - Maite F. S. Vaslin
- Plant Molecular Virology Laboratory, Department of Virology, Microbiology Institute, Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, Brazil
- Programa de Pós-graduação em Biotecnologia e Bioprocessos da UFRJ, Rio de Janeiro, Brazil
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Cotton Leafroll Dwarf Virus US Genomes Comprise Divergent Subpopulations and Harbor Extensive Variability. Viruses 2021; 13:v13112230. [PMID: 34835036 PMCID: PMC8618375 DOI: 10.3390/v13112230] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Revised: 10/29/2021] [Accepted: 11/02/2021] [Indexed: 11/21/2022] Open
Abstract
Cotton leafroll dwarf virus (CLRDV) was first reported in the United States (US) in 2017 from cotton plants in Alabama (AL) and has become widespread in cotton-growing states of the southern US. To investigate the genomic variability among CLRDV isolates in the US, complete genomes of the virus were obtained from infected cotton plants displaying mild to severe symptoms from AL, Florida, and Texas. Eight CLRDV genomes were determined, ranging in size from 5865 to 5867 bp, and shared highest nucleotide identity with other CLRDV isolates in the US, at 95.9–98.7%. Open reading frame (ORF) 0, encoding the P0 silencing suppressor, was the most variable gene, sharing 88.5–99.6% and 81.2–89.3% amino acid similarity with CLRDV isolates reported in cotton growing states in the US and in Argentina and Brazil in South America, respectively. Based on Bayesian analysis, the complete CLRDV genomes from cotton in the US formed a monophyletic group comprising three relatively divergent sister clades, whereas CLRDV genotypes from South America clustered as closely related sister-groups, separate from US isolates, patterns reminiscent of phylogeographical structuring. The CLRDV isolates exhibited a complex pattern of recombination, with most breakpoints evident in ORFs 2 and 3, and ORF5. Despite extensive nucleotide diversity among all available CLRDV genomes, purifying selection (dN/dS < 1) was implicated as the primary selective force acting on viral protein evolution.
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Coinfection of Cotton Plants with Watermelon Mosaic Virus and a Novel Polerovirus in China. Viruses 2021; 13:v13112210. [PMID: 34835016 PMCID: PMC8618073 DOI: 10.3390/v13112210] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Revised: 10/29/2021] [Accepted: 10/30/2021] [Indexed: 11/24/2022] Open
Abstract
Cotton is the most important fiber crop worldwide. To determine the presence of viruses in cotton plants showing leaf roll and vein yellowing symptoms in Henan Province of China, a small RNA-based deep sequencing approach was performed. Analysis of the de novo-assembled contigs followed by reverse transcription PCR allowed the reconstruction of watermelon mosaic virus and an unknown virus. The genome of the unknown virus was determined to be 5870 nucleotides in length, and has a genomic organization with characteristic features of previously reported poleroviruses. Sequence analysis revealed that the virus was closely related to, but significantly different from, cotton leafroll dwarf virus, a polerovirus of the family Solemoviridae. This virus had less than 90% amino acid sequence identity in the products of both ORF0 and ORF1. According to the polerovirus species demarcation criteria set by the International Committee on Taxonomy of Viruses, this virus should be assigned to a new polerovirus species, for which we propose the name “cotton leaf roll virus”.
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Tabassum A, Bag S, Suassuna ND, Conner KN, Chee P, Kemerait RC, Roberts P. Genome analysis of cotton leafroll dwarf virus reveals variability in the silencing suppressor protein, genotypes and genomic recombinants in the USA. PLoS One 2021; 16:e0252523. [PMID: 34232966 PMCID: PMC8262794 DOI: 10.1371/journal.pone.0252523] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Accepted: 05/17/2021] [Indexed: 11/18/2022] Open
Abstract
Cotton leafroll dwarf virus (CLRDV) is an emerging virus in cotton production in Georgia and several other Southeastern states in the USA. To better understand the genetic diversity of the virus population, the near complete genome sequences of six isolates from Georgia and one from Alabama were determined. The isolates sequenced were 5,866 nucleotides with seven open reading frames (ORFs). The isolates from Georgia were >94% identical with other isolates from the USA and South America. In the silencing suppressor protein (P0), at amino acid position 72, the isolates from Georgia and Alabama had a valine (V), similar to resistant-breaking ‘atypical’ genotypes in South America, while the Texas isolate had isoleucine (I), similar to the more aggressive ‘typical’ genotypes of CLRDV. At position 120, arginine (R) is unique to Georgia and China isolates, but absent in Alabama, Texas and South American isolates. Ten potential recombinant events were detected in the isolates sequenced. An increased understanding of CLRDV population structure and genetic diversity will help develop management strategies for CLRDV in the USA cotton belt.
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Affiliation(s)
- Afsha Tabassum
- Department of Plant Pathology, University of Georgia, Tifton, Georgia, United States of America
| | - Sudeep Bag
- Department of Plant Pathology, University of Georgia, Tifton, Georgia, United States of America
- * E-mail:
| | | | - Kassie N. Conner
- Alabama Cooperative Extension System, Auburn University, Auburn, Alabama, United States of America
| | - Peng Chee
- Institute of Plant Breeding, Genetics and Genomics, University of Georgia, Tifton, Georgia, United States of America
| | - Robert C. Kemerait
- Department of Plant Pathology, University of Georgia, Tifton, Georgia, United States of America
| | - Phillip Roberts
- Department of Entomology, University of Georgia, Tifton, Georgia, United States of America
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11
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Avelar S, Ramos-Sobrinho R, Conner K, Nichols RL, Lawrence K, Brown JK. Characterization of the Complete Genome and P0 Protein for a Previously Unreported Genotype of Cotton Leafroll Dwarf Virus, an Introduced Polerovirus in the United States. PLANT DISEASE 2020; 104:780-786. [PMID: 31958248 DOI: 10.1094/pdis-06-19-1316-re] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Virus-like disease symptoms consisting of leaf cupping, shortened internodes, and overall stunting were observed in commercial cotton fields in Alabama in 2017 to 2018. To determine the complete genome sequence of the suspected causal polerovirus, symptomatic leaf samples were collected in Macon County, Alabama, and subjected to Illumina RNA sequencing. Based on BLASTn analysis, the Illumina contig of 5,771 nt shared the highest nucleotide identity (approximately 95%) with members of the species Cotton leafroll dwarf virus (CLRDV) (genus Polerovirus; family Luteoviridae) from Argentina and Brazil. The full-length viral genome sequence was verified by reverse transcription (RT)-PCR amplification, cloning, and Sanger sequencing. The complete CLRDV genome of 5,865 nt in length shared 94.8 to 95.2% nucleotide identity with six previously reported CLRDV isolates. The genome of the CLRDV isolate amplified from Alabama samples (CLRDV-AL) has seven predicted open reading frames (ORFs). Viral proteins 1 to 5 (P1 to P5) shared 91.9 to 99.5% amino acid identity with the six CLRDV isolates from Argentina and Brazil. However, P0, the suppressor of host gene silencing, shared 82.4 to 88.5% pairwise amino acid identity with the latter CLRDV isolates. Phylogenetic analysis of the seven full-length CLRDV genomes resolved three sister clades: CLRDV-AL, CLRDV-typical, and CLRDV-atypical, respectively. Three recombination events were detected by the recombination detection program among the seven CLRDV isolates with breakpoints occurring along the genome. Pairwise nucleotide identity comparisons of ORF0 sequences for the three CLRDV-AL field isolates indicated that they were >99% identical, suggesting that this previously unknown CLRDV genotype represents a single introduction to Alabama.
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Affiliation(s)
- Sofia Avelar
- School of Plant Sciences, University of Arizona, Tucson, AZ 85721
| | | | - Kassie Conner
- Plant Diagnostic Laboratory, Alabama Cooperative Extension System, Auburn University, Auburn, AL 36849
| | | | - Kathy Lawrence
- Department of Entomology and Plant Pathology, Auburn University, Auburn, AL 36849
| | - Judith K Brown
- School of Plant Sciences, University of Arizona, Tucson, AZ 85721
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12
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Li Z, Davis JA, Swale DR. Chemical inhibition of Kir channels reduces salivary secretions and phloem feeding of the cotton aphid, Aphis gossypii (Glover). PEST MANAGEMENT SCIENCE 2019; 75:2725-2734. [PMID: 30785236 DOI: 10.1002/ps.5382] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2018] [Revised: 02/12/2019] [Accepted: 02/18/2019] [Indexed: 06/09/2023]
Abstract
BACKGROUND The unique feeding biology of aphids suggests novel insecticide targets are likely to exist outside of the nervous system. We therefore aimed to directly test the hypothesis that pharmacological inhibition of inward rectifier potassium (Kir) channels would result in salivary gland failure and reduced sap ingestion by the cotton aphid, Aphis gossypii. RESULTS The Kir inhibitors VU041 and VU590 reduced the length of the salivary sheath in a concentration dependent manner, indicating that the secretory activity of the salivary gland is reduced by Kir inhibition. Next, we employed the electrical penetration graph (EPG) technique to measure the impact Kir inhibition has to aphid sap feeding and feeding biology. Data show that foliar application of VU041 eliminated the E1 and E2 phases (phloem feeding) in all aphids studied. Contact exposure to VU041 after foliar applications was found to be toxic to A. gossypii at 72 and 96 h post-infestation, indicating mortality is likely a result of starvation and not acute toxicity. Furthermore, VU041 exposure significantly altered the feeding behavior of aphids, which is toxicologically relevant for plant-virus interactions. CONCLUSION These data suggest Kir channels are critical for proper function of aphid salivary glands and the reduced plant feeding justifies future work in developing salivary gland Kir channels as novel mechanism aphicides. Furthermore, products like VU041 would add to a very minor arsenal of compounds that simultaneously reduce vector abundance and alter feeding behavior. © 2019 Society of Chemical Industry.
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Affiliation(s)
- Zhilin Li
- Department of Entomology, Louisiana State University AgCenter, Baton Rouge, LA, USA
| | - Jeffrey A Davis
- Department of Entomology, Louisiana State University AgCenter, Baton Rouge, LA, USA
| | - Daniel R Swale
- Department of Entomology, Louisiana State University AgCenter, Baton Rouge, LA, USA
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Quan Q, Hu X, Pan B, Zeng B, Wu N, Fang G, Cao Y, Chen X, Li X, Huang Y, Zhan S. Draft genome of the cotton aphid Aphis gossypii. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2019; 105:25-32. [PMID: 30590189 DOI: 10.1016/j.ibmb.2018.12.007] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2018] [Revised: 12/03/2018] [Accepted: 12/14/2018] [Indexed: 05/15/2023]
Abstract
The cotton aphid Aphis gossypii Glover is a worldwide agricultural pest that feeds on cotton, melon, and other landscape plants, causing a high level of economic loss. In addition to the common characteristics shared with other aphids, Ap. gossypii has evolved multiple biotypes that present substantial differences in host adaption. These intriguing biological features are of interest from both a fundamental and applied perspective. However, the molecular studies of Ap. gossypii have been restrained by the lack of a reference genome. Furthermore, in order to establish a platform for the development of novel and sustainable control methods, it is necessary to generate genomic resources for Ap. gossypii. Here, we present a 294 Mb draft genome sequence of Ap. gossypii, which consists of 4,724 scaffolds with an N50 size of 438 kb. Compared to other aphid species with published genomes, Ap. gossypii presents the most compact genome size. A total of 14,694 protein-coding genes were predicted and annotated in the consensus gene set, 98.03% of CEGMA genes and 93.5% of BUSCO genes were captured respectively. Genome-wide selection analyses revealed that significantly evolving pathways in the genus Aphis are related to biological processes of detoxification, steroid biosynthesis, and ethylbenzene degradation. The acquisition of the genome of Ap. gossypii makes it possible to understand the molecular mechanism of intricate biological traits of this species, and will further facilitate the study of aphid evolution.
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Affiliation(s)
- Qingmei Quan
- Key Laboratory of Insect Developmental and Evolutionary Biology, CAS Center for Excellence in Molecular Plant Science, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, 200032, China
| | - Xiao Hu
- Key Laboratory of Insect Developmental and Evolutionary Biology, CAS Center for Excellence in Molecular Plant Science, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, 200032, China
| | - Bohu Pan
- Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Science, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, 200032, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Baosheng Zeng
- Key Laboratory of Insect Developmental and Evolutionary Biology, CAS Center for Excellence in Molecular Plant Science, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, 200032, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Ningning Wu
- Key Laboratory of Insect Developmental and Evolutionary Biology, CAS Center for Excellence in Molecular Plant Science, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, 200032, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Gangqi Fang
- Key Laboratory of Insect Developmental and Evolutionary Biology, CAS Center for Excellence in Molecular Plant Science, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, 200032, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Yanghui Cao
- Key Laboratory of Insect Developmental and Evolutionary Biology, CAS Center for Excellence in Molecular Plant Science, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, 200032, China
| | - Xiaoya Chen
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, 200032, China; Plant Science Research Center, Shanghai Key Laboratory of Plant Functional Genomics and Resources, Shanghai Chenshan Botanical Garden, Shanghai, 201602, China
| | - Xuan Li
- Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Science, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, 200032, China
| | - Yongping Huang
- Key Laboratory of Insect Developmental and Evolutionary Biology, CAS Center for Excellence in Molecular Plant Science, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, 200032, China.
| | - Shuai Zhan
- Key Laboratory of Insect Developmental and Evolutionary Biology, CAS Center for Excellence in Molecular Plant Science, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, 200032, China.
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