Genome sequence of Erinnyis ello granulovirus (ErelGV), a natural cassava hornworm pesticide and the first sequenced sphingid-infecting betabaculovirus

BACKGROUND: Cassava (Manihot esculenta) is the basic source for dietary energy of 500 million people in the world. In Brazil, Erinnyis ello ello (Lepidoptera: Sphingidae) is a major pest of cassava crops and a bottleneck for its production. In the 1980s, a naturally occurring baculovirus was isolated from E. ello larva and successfully applied as a bio-pesticide in the field. Here, we described the structure, the complete genome sequence, and the phylogenetic relationships of the first sphingid-infecting betabaculovirus. RESULTS: The baculovirus isolated from the cassava hornworm cadavers is a betabaculovirus designated Erinnyis ello granulovirus (ErelGV). The 102,759 bp long genome has a G + C content of 38.7%. We found 130 putative ORFs coding for polypeptides of at least 50 amino acid residues. Only eight genes were found to be unique. ErelGV is closely related to ChocGV and PiraGV isolates. We did not find typical homologous regions and cathepsin and chitinase homologous genes are lacked. The presence of he65 and p43 homologous genes suggests horizontal gene transfer from Alphabaculovirus. Moreover, we found a nucleotide metabolism-related gene and two genes that could be acquired probably from Densovirus. CONCLUSIONS: The ErelGV represents a new virus species from the genus Betabaculovirus and is the closest relative of ChocGV. It contains a dUTPase-like, a he65-like, p43-like genes, which are also found in several other alpha- and betabaculovirus genomes, and two Densovirus-related genes. Importantly, recombination events between insect viruses from unrelated families and genera might drive baculovirus genomic evolution. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/1471-2164-15-856) contains supplementary material, which is available to authorized users

Horizontal and vertical structure of reactive bromine events probed by bromine monoxide MAX-DOAS spectroscopy

Heterogeneous photochemistry converts bromide (Br−) to reactive bromine species (Br atoms and bromine monoxide, BrO) that dominate Arctic springtime chemistry. This phenomenon has many impacts such as boundary-layer ozone depletion, mercury oxidation and deposition, and modification of the fate of hydrocarbon species. To study environmental controls on reactive bromine events, the BRomine, Ozone, and Mercury EXperiment (BROMEX) was carried out from early March to mid-April 2012 near Barrow (Utqiaġvik), Alaska. We measured horizontal and vertical gradients in BrO with multiple-axis differential optical absorption spectroscopy (MAX-DOAS) instrumentation at three sites, two mobile and one fixed. During the campaign, a large crack in the sea ice (an open lead) formed pushing one instrument package ∼ 250 km downwind from Barrow (Utqiaġvik). Convection associated with the open lead converted the BrO vertical structure from a surface-based event to a lofted event downwind of the lead influence. The column abundance of BrO downwind of the re-freezing lead was comparable to upwind amounts, indicating direct reactions on frost flowers or open seawater was not a major reactive bromine source. When these three sites were separated by ∼ 30 km length scales of unbroken sea ice, the BrO amount and vertical distributions were highly correlated for most of the time, indicating the horizontal length scales of BrO events were typically larger than ∼ 30 km in the absence of sea ice features. Although BrO amount and vertical distribution were similar between sites most of the time, rapid changes in BrO with edges significantly smaller than this ∼ 30 km length scale episodically transported between the sites, indicating BrO events were large but with sharp edge contrasts. BrO was often found in shallow layers that recycled reactive bromine via heterogeneous reactions on snowpack. Episodically, these surface-based events propagated aloft when aerosol extinction was higher (\u3e 0.1 km−1); however, the presence of aerosol particles aloft was not sufficient to produce BrO aloft. Highly depleted ozone (−1) repartitioned reactive bromine away from BrO and drove BrO events aloft in cases. This work demonstrates the interplay between atmospheric mixing and heterogeneous chemistry that affects the vertical structure and horizontal extent of reactive bromine events

Molecular biology of baculovirus and its use in biological control in Brazil

Os baculovírus são vírus patogênicos a insetos, encontrados principalmente na ordem Lepidoptera. A família Baculoviridae é taxonomicamente dividida em dois gêneros: Nucleopolyhedrovirus e Granulovirus, que diferem pela morfologia do corpo de oclusão. Os nucleopoliedrovírus (NPV) possuem corpos de inclusão poliédrica (PIB), contendo múltiplas partículas virais, enquanto os granulovírus (GV) contêm, em geral, partículas únicas, ocluídas em corpos protéicos de forma ovóide. Durante o ciclo de vida são produzidos dois tipos de progênies virais: BV ("Budded Virus") e PDV ("Polyhedra Derived Virus"), que são essenciais para o processo de infecção e propagação do vírus. Os baculovírus têm sido empregados no controle de pragas e, por serem específicos e restritos a invertebrados, são considerados agentes seguros de controle biológico. Recentemente têm sido amplamente utilizados como vetor de expressão de genes heterólogos por produzirem e processarem, em grande quantidade, proteínas de procariotos e eucariotos. Além disso, técnicas de DNA recombinante têm permitido a produção de inseticidas virais geneticamente modificados. Este trabalho constitui uma revisão sobre a taxonomia, estrutura, replicação e biologia molecular de baculovírus e sobre seu uso como bioinseticida no Brasil.Baculoviruses are insect viruses found mainly in Lepidoptera. The family Baculoviridae is taxonomically divided in two genera, Nucleopolyhedrovirus and Granulovirus, which differ by occlusion body morphology. NPVs (Nucleopolyhedroviruses) have polyhedrical inclusion bodies (PIBs) containing multiple viral particles, while GVs (Granuloviruses) appear to be generally single particles occluded in oval shaped occlusion bodies. During the life cycle, two different viral progenies are produced: BV (Budded Virus) and PDV (Polyhedra Derived Virus), which are essential for the infectious process and virus propagation in host cells. Baculoviruses are being used for pest control and they are especially safe due to their specificity and invertebrate-restricted host range. Baculoviruses have been used as vectors for high level protein expression ofheterologous genes from prokaryotic and eukaryotic organisms. Also, recombinant DNA techniques have allowed the production of genetically modified viral insecticides. This study is a review on the taxonomy, structure, replication and molecular biology of baculoviruses, as well as their use as bioinsecticides in Brazil

Observations of bromine monoxide transport in the Arctic sustained on aerosol particles

The return of sunlight in the polar spring leads to the production of reactive halogen species from the surface snowpack, significantly altering the chemical composition of the Arctic near-surface atmosphere and the fate of long-range transported pollutants, including mercury. Recent work has shown the initial production of reactive bromine at the Arctic surface snowpack; however, we have limited knowledge of the vertical extent of this chemistry, as well as the lifetime and possible transport of reactive bromine aloft. Here, we present bromine monoxide (BrO) and aerosol particle measurements obtained during the March 2012 BRomine Ozone Mercury EXperiment (BROMEX) near Utqiaġvik (Barrow), AK. The airborne differential optical absorption spectroscopy (DOAS) measurements provided an unprecedented level of spatial resolution, over 2 orders of magnitude greater than satellite observations and with vertical resolution unable to be achieved by satellite methods, for BrO in the Arctic. This novel method provided quantitative identification of a BrO plume, between 500 m and 1 km aloft, moving at the speed of the air mass. Concurrent aerosol particle measurements suggest that this lofted reactive bromine plume was transported and maintained at elevated levels through heterogeneous reactions on colocated supermicron aerosol particles, independent of surface snowpack bromine chemistry. This chemical transport mechanism explains the large spatial extents often observed for reactive bromine chemistry, which impacts atmospheric composition and pollutant fate across the Arctic region, beyond areas of initial snowpack halogen production. The possibility of BrO enhancements disconnected from the surface potentially contributes to sustaining BrO in the free troposphere and must also be considered in the interpretation of satellite BrO column observations, particularly in the context of the rapidly changing Arctic sea ice and snowpack

Financial management: text and cases/ Philippatos

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Baculovirus biopesticides – a safe alternative to chemical protection of plants

ABSTRACT Chemical pest control agents, though extensively used in all countries of the world, have been widely regarded as ecologically unacceptable. Therefore, there is the increased social pressure to replace them gradually with biopesticides which are safe to humans and non-target organisms. Viruses of a few families infect invertebrates but only those belonging to the family Baculoviridae have been used as biopesticides because they are safe to wildlife and their specificity is very narrow. Until recently, the application as bioinsectides was limited because of their slow killing action and technical problems for in vitro commercial production. However, successful protection of large area of soybean fields in Brazil revived the interest in baculoviruses as effective agents for biocontrol and the wider application for pest control is very likely to occur in future. To improve baculovirus killing properties, two approaches can be foreseen: i) in countries where use of genetically modified organisms is restricted, changes in biopesticide formulations and the improvements of the in vitro production are to be expected, ii) in countries with more relaxed attitude towards genetically modified organisms, the killing activity of baculoviruses will be improved by genetic modifications of the baculovirus genome

Infectividade in vitro de Spodoptera frugiperda multiple nucleopolyhedrovirus a diferentes linhagens celulares de insetos

The objective of this work was to evaluate the response of an in vitro host range to Spodoptera frugiperda multiple nucleopolyhedrovirus (SfMNPV), a pathogenic virus to the fall armyworm (Spodoptera frugiperda, Lepidoptera: Noctuidae), for the further development of a biopesticide based on cell culture systems. The cell lines from Bombyx mori (BM-5), Lymantria dispar (IPLB-LD-625Y), Trichoplusia ni (BTI-Tn-5B1-4), Anticarsia gemmatalis (UFL-AG-286), and S. frugiperda (IPLB-SF-21AE and Sf9) were tested for their susceptibility to a highly-virulent Brazilian isolate of SfMNPV. The cytopathic effects induced by the virus, the production of viral particles, and the synthesis of viral polypeptides were examined and compared. Both S. frugiperda cell lines showed hypertrophy of cell nuclei and production of many polyhedra. The SDS-Page of radiolabed proteins showed that the cell protein synthesis was shutoff, while an intense band of about 30 kDa, recognized as polyhedrin, was synthesized. The other cell lines did not show polyhedra production, although some of them underwent morphological changes and protein synthesis shutdown in response to virus infection. The SF-21 and Sf9 cell lines are recommended for further in vitro production of SfMNPV.O objetivo deste trabalho foi avaliar uma gama de hospedeiros, in vitro, quanto à resposta a Spodoptera frugiperda multiple nucleopolyhedrovirus (SfMNPV), um vírus patogênico à lagarta-do-cartucho (Spodoptera frugiperda; Lepidoptera: Noctuidae), para o posterior desenvolvimento de um biopesticida baseado em sistema de cultura de células. As linhagens celulares de Bombyx mori (BM-5), Lymantria dispar (IPLB-LD-625Y), Trichoplusia ni (BTI-Tn-5B1-4), Anticarsia gemmatalis (UFL-AG-286) e S. frugiperda (IPLB-SF-21AE e Sf9) foram testadas quanto a sua suscetibilidade a um isolado brasileiro de SfMNPV altamente virulento. Os efeitos citopáticos induzidos pelo vírus, a produção de partículas virais e a síntese de polipeptídeos virais foram examinados e comparados. Ambas as células de S. frugiperda apresentaram hipertrofia dos núcleos celulares e produção de muitos poliedros. O SDS-Page de proteínas com radiomarcação mostrou que as proteínas celulares apresentaram inibição de síntese, enquanto uma intensa banda de cerca de 30 kDa, reconhecida como poliedrina, era sintetizada. As outras linhagens celulares não apresentaram produção de poliedros, apesar de algumas terem apresentado alterações morfológicas e inibição de síntese proteica em resposta à infecção viral. As linhagens celulares SF-21 e Sf9 são recomendadas para a posterior produção in vitro de SfMNPV.