scholarly journals Cotton Leafroll Dwarf Virus US Genomes Comprise Divergent Subpopulations and Harbor Extensive Variability

Viruses ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 2230
Author(s):  
Roberto Ramos-Sobrinho ◽  
Raphael O. Adegbola ◽  
Kathy Lawrence ◽  
Drew W. Schrimsher ◽  
Thomas Isakeit ◽  
...  

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.

2020 ◽  
Vol 21 (2) ◽  
pp. 142-143 ◽  
Author(s):  
Trey Price ◽  
Rodrigo Valverde ◽  
Raghuwinder Singh ◽  
Jeff Davis ◽  
Sebe Brown ◽  
...  

Cotton leafroll dwarf virus (CLRDV) has recently been discovered in the southern United States. The virus is transmitted by the cotton aphid and causes numerous symptoms including foliar chlorosis, distortion, leaf cupping, and reddened leaf veins. These symptoms were observed in a field in northeast Louisiana during the summer of 2019 approximately 2 weeks after cotton aphid infestation. Grafting infected cotton plants with healthy ones resulted in similar symptom development, and molecular diagnosis initially indicated and then confirmed the presence of CLRDV in sampled and grafted specimens, respectively. This the first report of CLRDV in Louisiana.


2017 ◽  
Vol 107 (3) ◽  
pp. 369-376 ◽  
Author(s):  
Yamila C. Agrofoglio ◽  
Verónica C. Delfosse ◽  
María F. Casse ◽  
Horacio E. Hopp ◽  
Iván Bonacic Kresic ◽  
...  

An outbreak of a new disease occurred in cotton (Gossypium hirsutum) fields in northwest Argentina starting in the 2009–10 growing season and is still spreading steadily. The characteristic symptoms of the disease included slight leaf rolling and a bushy phenotype in the upper part of the plant. In this study, we determined the complete nucleotide sequences of two independent virus genomes isolated from cotton blue disease (CBD)-resistant and -susceptible cotton varieties. This virus genome comprised 5,866 nucleotides with an organization similar to that of the genus Polerovirus and was closely related to cotton leafroll dwarf virus, with protein identity ranging from 88 to 98%. The virus was subsequently transmitted to a CBD-resistant cotton variety using Aphis gossypii and symptoms were successfully reproduced. To study the persistence of the virus, we analyzed symptomatic plants from CBD-resistant varieties from different cotton-growing fields between 2013 and 2015 and showed the presence of the same virus strain. In addition, a constructed full-length infectious cDNA clone from the virus caused disease symptoms in systemic leaves of CBD-resistant cotton plants. Altogether, the new leafroll disease in CBD-resistant cotton plants is caused by an atypical cotton leafroll dwarf virus.


2020 ◽  
Vol 4 (1) ◽  
pp. 1-20
Author(s):  
John Parsons

Narratives of security and threat are continually used to justify morally contentious activities. In the past three years, the United States’ government has increasingly promoted narratives of “criminal migrants” and “immigrant invasions.” In response to perceived threats, the US-Mexico border has undergone a process of militarization. During this time, various border militias have continued to operate along the southern US border. My research was conducted over 11 months with two militias operating on the US-Mexico border I have labeled Border Watch. This militia provides a snippet of how morality is operationalized in the legitimization of actions and how morality is intrinsically linked to security in the lived experiences of its volunteers. In this article, I argue that the volunteers make sense of their experiences away from the border through the narrative espoused by the US government. The resonance between experience and narrative defines the latter as truth and the ability to dismiss counter-narratives. For the volunteers of Border Watch who adhere to a notion of citizenship through the lens of the citizen-soldier ideal, the narrative delivers a moral imperative to act in defense of the nation. Within the nexus of danger, security, and morality, the volunteers of Border Watch conceptualize their project as one in which moral citizens protect the nation and its citizens from an evil Other.


2021 ◽  
Author(s):  
Andrew Tiu ◽  
Zachary Susswein ◽  
Alexes Merritt ◽  
Shweta Bansal

AbstractIt is critical that we maximize vaccination coverage across the United States so that SARS-CoV-2 transmission can be suppressed, and we can sustain the recent reopening of the nation. Maximizing vaccination requires that we track vaccination patterns to measure the progress of the vaccination campaign and target locations that may be undervaccinated. To improve efforts to track and characterize COVID-19 vaccination progress in the United States, we integrate CDC and state-provided vaccination data, identifying and rectifying discrepancies between these data sources. We find that COVID-19 vaccination coverage in the US exhibits significant spatial heterogeneity at the county level and statistically identify spatial clusters of undervaccination, all with foci in the southern US. Vaccination progress at the county level is also variable; many counties stalled in vaccination into June 2021 and few recovered by July, with transmission of the Delta variant rapidly rising. Using a comparison with a mechanistic growth model fitted to our integrated data, we classify vaccination dynamics across time at the county scale. Our findings underline the importance of curating accurate, fine-scale vaccination data and the continued need for widespread vaccination in the US, especially in the wake of the highly transmissible Delta variant.


2016 ◽  
Vol 11 (1) ◽  
pp. 274
Author(s):  
Lucas Pereira Rezende

Esse artigo busca fazer um estudo da balança de poder na América do Sul, através de um levantamento quantitativo e qualitativo de 15 indicadores de poder: (1) tamanho da população; (2) tamanho do Produto Interno Bruto; (3) os Correlates of War (COW); (4) os gastos absolutos em defesa; (5) o percentual do PIB gasto em defesa; (6) o número total de efetivos nas Forças Armadas ativas; (7) o total de efetivos nos Exércitos; (8) o total de efetivos nas Marinhas; (9) o total de efetivos nas Forças Aéreas; (10) o total de veículos blindados; (11) o total de peças de artilharia; (12) o total de submarinos; (13) o total de embarcações de guerra; (14) o total de aviões de combate; e (15) o índex Global Fire Power. Partindo dos indicadores comumente utilizados pela literatura para medir poder, como o tamanho do PIB, os COW e os gastos em defesa - indicadores utilizados por Wohlforth (1999 e 2009) para sustentar a unipolaridade estadunidense, o Brasil seria, também, uma unipolaridade da América do Sul. Todavia, quando adicionamos os outros indicadores específicos de mensuração da capacidade militar atual sul-americana, vimos que a tendência brasileira à unipolaridade não se sustenta. Há uma grande defasagem, em termos comparativos, das Forças Armadas brasileiras frente às demais na América do Sul, levando em consideração seu tamanho territorial, populacional e PIB. Isso faz com que, por esses outros indicadores, observássemos uma tendência a uma multipolaridade desequilibrada. Mesmo que tenha programas de reaparelhamento de suas Forças Armadas, o Brasil não é o único a fazê-lo. Isso pode indicar que, tal qual se observou no campo global com os Estados Unidos no pós-Guerra Fria, a unipolaridade brasileira possa ser um fenômeno de curta duração, ainda que a maioria dos indicadores mostre estar, do início do século até 2013, em ascendência. Abstract This article seeks to make a study of the balance of power in South America through a quantitative and qualitative survey of 15 power indicators: (1) size of the population; (2) size of gross domestic product; (3) the Correlates of War (COW); (4) the absolute defense spending; (5) the percentage of GDP spent on defense; (6) the total number of personnel in the active military; (7) the total personnel in Armies; (8) the total personnel in Marine; (9) the total personnel in the Air Force; (10) the total number of armored vehicles; (11) the total number of artillery pieces; (12) total figure of submarines; (13) total figure of war vessels; (14) the total number of combat aircrafts; and (15) the index Global Fire Power. Based on the indicators commonly used in the literature to measure power, as the size of GDP, the COW and defense spending - indicators used by Wohlforth (1999 and 2009) to support the US unipolarity, Brazil was also a unipolar power in South America. However, when we add other specific indicators to measure the current military capability of South American states, we see the Brazilian tendency to unipolarity does not hold. There is a large gap, in comparative terms, between the Brazilian Armed Forces and the other South American actors, taking into account their territorial size, population and GDP. Taking these indicators into account, we could describe the system as an unbalanced multipolarity. Even if there is a re-equipment program of its armed forces, Brazil is not the only one to do so. This may indicate that, as it was observed in the global system with the United States in the post-Cold War, the Brazilian unipolarity may be a short-term phenomenon, although most indicators show that, from the beginning of the century to 2013, Brazilian capabilities were rising.


Author(s):  
Tore C. Olsson

This chapter explores the last great exchange of the US–Mexican agrarian dialogue: the Mexican government's enthusiastic embrace of the Tennessee Valley Authority's (TVA) hydraulic development program after World War II. More than any other New Deal agency, it was the TVA's monumental effort to harness waterpower for social and environmental transformation that most deeply impacted the Mexican countryside. When in 1947 Miguel Alemán made the first Mexican presidential tour of the United States since the revolution's outbreak in 1910, northern Alabama and eastern Tennessee were foremost on his trip agenda. His pilgrimage would engender extensive discussion among Mexican policy makers about the similarities between the southern US and their own tropical south, coming to a climax in the several river valley commissions that Alemán established in 1947 to replicate the TVA's ambiguous success in coastal southern Mexico.


Plant Disease ◽  
2020 ◽  
Vol 104 (3) ◽  
pp. 780-786 ◽  
Author(s):  
Sofia Avelar ◽  
Roberto Ramos-Sobrinho ◽  
Kassie Conner ◽  
Robert L. Nichols ◽  
Kathy Lawrence ◽  
...  

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.


2020 ◽  
Vol 9 (34) ◽  
Author(s):  
Afsha Tabassum ◽  
Phillip M. Roberts ◽  
Sudeep Bag

ABSTRACT Cotton leafroll dwarf disease (CLRDD), caused by the aphid-borne Cotton leafroll dwarf virus (CLRDV; genus, Polerovirus; family, Luteoviridae), has been recently reported from the major cotton-growing regions of the United States. Here, we present the nearly complete genome sequence of a CLRDV isolate from cotton in Georgia.


2011 ◽  
Vol 101 (12) ◽  
pp. 1446-1456 ◽  
Author(s):  
Olufemi J. Alabi ◽  
Maher Al Rwahnih ◽  
Gandhi Karthikeyan ◽  
Sudarsana Poojari ◽  
Marc Fuchs ◽  
...  

The genetic diversity of 34 isolates of Grapevine leafroll-associated virus 1 (GLRaV-1) from different wine, table, and ornamental grape cultivars in California, New York, and Washington States in the United States was investigated. Segments of the heat-shock protein 70 homolog (HSP70h) gene, coat protein (CP) gene, coat protein duplicate 2 (CPd2) gene, and open reading frame 9 (p24) were amplified by reverse-transcription polymerase chain reaction, cloned, and sequenced. A pairwise comparison of nucleotide sequences revealed intra- and interisolate sequence diversity, with CPd2 and HSP70h being the most and the least divergent, respectively, among the four genomic regions studied. The normalized values for the ratio of nonsynonymous substitutions per nonsynonymous site to synonymous substitutions per synonymous site indicated different purifying selection pressures acting on each of the four genomic regions, with the CP and CPd2 being subjected to the strongest and weakest functional constraints, respectively. A global phylogenetic analysis of sequences from the four genomic regions revealed segregation of GLRaV-1 isolates into three major clades and a lack of clearly defined clustering by geographical origin. In contrast, only two lineages were apparent when the CP and CPd2 gene sequences were used in phylogenetic analyses. Putative recombination events were revealed among the HSP70h, CP, and p24 sequences. The genetic landscape of GLRaV-1 populations presented in this study provides a foundation for better understanding of the epidemiology of grapevine leafroll disease across grape-growing regions in the United States. In addition, this study will benefit grape clean plant programs across the country in improving the sanitary status of planting materials provided to nurseries and grape growers.


2016 ◽  
Vol 4 (4) ◽  
pp. 166-189 ◽  
Author(s):  
Tara Magner

Members of Congress have introduced numerous pieces of legislation in recent years related to refugees, asylum seekers, and other populations of migrants seeking protection in the United States. These bills were drafted in reaction to dramatic events within the United States, at its borders, and around the world. For example, roughly 400,000 children traveling alone and mothers with children have arrived at the southern US border since 2013, many seeking protection from organized crime, gang violence, and threats of human trafficking. Similarly, more than a million refugees from the Middle East, North Africa, and Asia sought to reach safety on the European continent in 2015 alone. Terrorist attacks fueled attempts to curtail the US commitment to offer protection to those fleeing persecution, even when those attacks had no connection to refugees or only tenuous links. And yet existing US law has been left virtually unchanged throughout this tumultuous period. This article describes the significant attempts to enact legislation related to refugees and international migrants since 2013 and examines the reasons why those attempts have not succeeded. It also describes American attitudes toward refugees and assesses whether those attitudes affected the fate of legislation.


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