In Brazil, at least eight begomoviruses including Tomato rugose mosaic virus (ToRMV) and Tomato yellow spot virus (ToYSV) infect tomatoes. ToYSV symptoms in tomato and Nicotiana benthamiana appear earlier and are more severe compared to those of ToRMV. We investigated the role of several factors in this differential adaptation. To analyze infection kinetics, a single leaf was inoculated and subsequently detached after different periods of time. Viral DNA accumulation was quantified in plants, viral replication was analyzed in protoplasts, and tissue tropism was determined by in situ hybridization. Results indicate that ToYSV establishes a systemic infection and reaches a higher concentration earlier than ToRMV in both hosts. ToRMV negatively interferes with ToYSV during the initial stages of infection, but once systemic infection is established this interference ceases. In N. benthamiana, ToYSV invades the mesophyll, while ToRMV is phloem-restricted. During dual infection in this host, ToYSV releases ToRMV from the phloem.

BackgroundBegomoviruses are dicot-infecting, whitefly-transmitted viruses with a genome comprised of one or two molecules of circular, single-stranded DNA. In Brazil, tomato-infecting begomoviruses have emerged as serious pathogens since the introduction of a new biotype of the insect vector in the mid-1990’s. Tomato rugose mosaic virus (ToRMV) and Tomato severe rugose virus (ToSRV) are often found in tomato fields. The complete sequence of the DNA-B components of ToSRV and ToRMV show an identity of 98.2%. Additionally, the high nucleotide identity (96.2%) between their common regions indicates that these two viruses may share the same DNA-B.MethodsTomato seedlings were biolistically inoculated with ToSRV (DNA-A and DNA-B) and ToRMV (DNA-A and DNA-B) infectious clones in every possible combination of single or mixed infection. Symptom expression was evaluated for up to 35 days post-inoculation (dpi). DNA was extracted at 28 dpi and the presence of each viral genomic component was examined by rolling circle amplification (RCA) followed by digestion, as well as by quantitative, real-time PCR. Sequence comparisons, recombination and phylogenetic analyzes were performed using EMBOSS needle, RDP program and maximum likelihood inference, respectively.ResultsSymptoms in tomato plants inoculated with the different combinations of ToRMV and ToSRV DNA-A and DNA-B components consisted of a typical mosaic in all combinations. Pseudorecombinants were formed in all possible combinations. When two DNA-A or two DNA-B components were inoculated simultaneously, the ToRMV components were detected preferentially in relation to the ToSRV components. The combination of minor changes in both the Rep protein and the CR may be involved in the preferential replication of ToRMV components. Recombination and phylogenetic analyzes support the exchange of genetic material between ToRMV and ToSRV.ConclusionsToRMV and ToSRV form viable pseudorecombinants in their natural host (Solanum lycopersicum) and share the same DNA-B. ToRMV DNA components are preferentially replicated over ToSRV components. These results indicate that the emergence of ToRMV involved both recombination and pseudorecombination, further highlighting the importance of these mechanisms in the emergence and adaptation of begomoviruses.

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Garlic cultivars in Brazil are infected by a complex of viruses and for some virus species, such as the allexivirus, purification of the virions is sometimes cumbersume. To overcome this problem, recombinant expression of viral proteins in heterologous systems is an alternative method for producing antibodies. The capsid gene from Garlic virus C (GarV-C), an Allexivirus, was inserted into the genome of Autographa californica multiple nucleopolyhedrovirus (AcMNPV) generating the recombinant virus vSynGarV-C. The recombinant protein expression was confirmed by SDS-PAGE and western-blot of extracts from recombinant virus infected insect cells, where a protein band of approximately 32KDa was observed only in extracts from recombinant infected cells. This protein corresponded to the predicted size of the capsid protein of the GarV-C. A rabbit polyclonal antibody was raised against this protein, shown to be specific for the GarV-C protein in western-blot and dot-Elisa, however with a low titer.

The present study aimed to assess the natural resistance of four Amazon tropical wood species, used in the production of sawn timber, against infection with xylophagous fungi. Apuleia leiocarpa (amarelão), Dinizia excelsa (angelim vermelho), Vochysia maxima (quaruba), and Bagassa guianensis (tatajuba) were selected to perform the accelerated laboratory test. These species were exposed to white rot xylophagous fungi Pycnoporus sanguineus, Phanerochaete chrysosporium and Schizophyllum commune, and to the brown rot fungus Gloeophyllum abietinum. The laboratory test was performed following the methodology and classification of the natural resistance of wood according to ASTM D2017-86 (American Society for Testing Materials). All species were classified as highly resistant to fungal attack; however, V. maxima lost the highest percentage of weight. Therefore, we recommend that D. excelsa, A. leiocarpa, and B. guianensis be used in the production of sawn timber since they exhibited lower weight loss in the presence of all the fungi tested during a period of 12 weeks.

Chrysanthemum is one of the most commercialized cut flowers on world market. After cutting, it becomes highly perishable due to the increased metabolic activity that leads to senescence. Thus, the experiment was carried out in order to evaluate action of maintenance solutions on the postharvest physiology cutting chrysanthemums of the cultivar Framint. A completely randomized design was used in the factorial scheme composed of two factors: four postharvest treatments and seven evaluation times. The flowers remained in the following maintenance solutions: citric acid solution, solution with boric acid, and salicylic acid solution at concentrations 100 mg. L-1 for both treatments in combination with 1% ethanol. During postharvest period, following analyzes were performed: fresh mass loss, volume of water absorbed, luminosity (petals), activity of the enzymes ascorbate peroxidase (APX), catalase (CAT), peroxidase (POD), superoxide dismutase (SOD), total protein and total carbohydrate content. The treatment with citric acid + ethanol was the most adequate to conserve the quality and to prolong longevity of the flowers, being confirmed by the smaller loss of fresh mass, respiratory activity, better maintenance of carbohydrate and protein content.

Introdução: A cirurgia videolaparoscópica é um método cirúrgico minimamente invasivo do abdômen e seus órgãos internos, realizada através de uma câmera ligada através da parede abdominal por meio de pinças pelo cirurgião. As cirurgias mais comuns por laparoscopia são: bariátrica, ginecológica, tratamento de hérnias abdominais, entre outras. Objetivo: Mostrar as vantagens e desvantagens da cirurgia videolaparoscópica e estudar os avanços em relação a novas técnicas utilizadas na medicina em relação a cirurgia. Método: Trata-se de uma pesquisa descritiva do tipo revisão integrativa de literatura, que busca relatar os pontos positivos e negativos da cirurgia videolaparoscópica em relação a laparatomia. A pesquisa foi realizada por meio de bases de dados PubMed MEDLINE, Scientific Electronic Library Online (Scielo), Cochrane Library, Google Scholar, LILACS e Google acadêmico, durante os meses de julho e agosto de 2021. Dessa maneira, totalizaram-se 29 produções científicas para revisão integrativa da literatura. Resultados: Tendo em vista os procedimentos cirúrgicos envolvendo a laparoscopia e a laparotomia, é possível perceber maiores benefícios no primeiro procedimento, como uma alta hospitalar mais rápida pela incisão minimamente invasiva que esta permite. Conclusão: A videolaparoscopia é um procedimento moderno e menos invasivo, usado como alternativa para a laparotomia, possuindo vantagens como um menor tempo cirúrgico, redução de complicações e morbimortalidade e um melhor resultado estético da cicatrização, mas também desvantagens como lesão nos órgãos e vasos, herniação ou diminuição na capacidade residual pulmonar. Com isso, a laparotomia é mais necessária em pacientes com riscos cardíacos e pulmonares.

Background The necessity of a competent vector for transmission is a primary ecological factor driving the host range expansion of plant arthropod-borne viruses, with vectors playing an essential role in disease emergence. Cassava begomoviruses severely constrain cassava production in Africa. Curiously, begomoviruses have never been reported in cassava in South America, the center of origin for this crop. It has been hypothesized that the absence of a competent vector in cassava is the reason why begomoviruses have not emerged in South America. Methods We performed a country-wide whitefly diversity study in cassava in Brazil. Adults and/or nymphs of whiteflies were collected from sixty-six cassava fields in the main agroecological zones of the country. A total of 1,385 individuals were genotyped based on mitochondrial cytochrome oxidase I sequences. Results A high species richness was observed, with five previously described species and two putative new ones. The prevalent species were Tetraleurodes acaciae and Bemisia tuberculata, representing over 75% of the analyzed individuals. Although we detected, for the first time, the presence of Bemisia tabaci Middle East-Asia Minor 1 (BtMEAM1) colonizing cassava in Brazil, it was not prevalent. The species composition varied across regions, with fields in the Northeast region showing a higher diversity. These results expand our knowledge of whitefly diversity in cassava and support the hypothesis that begomovirus epidemics have not occurred in cassava in Brazil due to the absence of competent vector populations. However, they indicate an ongoing adaptation process of BtMEAM1 to cassava, increasing the likelihood of begomovirus emergence in this crop.