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Biology subjects

Nome, C.

Publications and source records attributed to Nome, C..

4 recordsLinked to original sources

Highly sensitive reverse transcription loop-mediated isothermal amplification for detecting and identifying groundnut ringspot and tomato spotted wilt orthotospoviruses

Orthotospovirus arachianuli (groundnut ringspot virus, GRSV) and Orthotospovirus tomatomaculae (tomato spotted wilt virus, TSWV) represent a threat to several agricultural crops worldwide. The management of the diseases they cause is particularly challenging due to their wide host range and transmission by thrips vectors. Accurate diagnosis and early detection are crucial, especially considering the limitations of conventional serological and molecular methods. This study introduces reverse transcription loop-mediated isothermal amplification (RT-LAMP) as a reliable alternative for detecting and identifying GRSV and TSWV in tomato, pepper, and peanut plants. The designed primer sets specifically targeted and amplified fragments of the viral RNA S segment. RT-LAMP reactions produced negative results in the healthy plants and exhibited no cross-reactivity with closely related orthotospoviruses or viruses from other genera. Compared to RT-PCR, RT-LAMP exhibited superior sensitivity, detecting viral RNA at concentrations 100 times lower. Field testing on symptomatic plants further confirmed the effectiveness of this technique. Overall, this study highlights RT-LAMP as a rapid, species-specific, and highly sensitive tool for the early detection of GRSV and TSWV in economically important crops, offering a promising solution for improved disease management.

molecular biology↗

An unwanted association: the threat to papaya crops by a novel potexvirus in northwest Argentina

An emerging virus isolated from papaya (Carica papaya) crops in northwestern (NW) Argentina was sequenced and characterized using next-generation sequencing. The resulting genome is 6,667-nt long and encodes five open reading frames in an arrangement typical of other potexviruses. This virus appears to be a novel member within the genus Potexvirus. Blast analysis of RNA-dependent RNA polymerase (RdRp) and coat protein (CP) genes showed the highest amino acid sequence identity (67% and 71%, respectively) with pitaya virus X. Based on nucleotide sequence similarity and phylogenetic analysis, the name papaya virus X is proposed for this newly characterized potexvirus that was mechanically transmitted to papaya plants causing chlorotic patches and severe mosaic symptoms. RT-PCR based detection of papaya virus X (PapVX) revealed that it is widely present in papaya crops from NW Argentina. The prevalence of PapVX, which seems to be restricted to the NW region of Argentina, and the fact that it has only been detected in this region could be associated with a recent emergence or adaptation of this virus to papaya in NW Argentina.

microbiology↗

Molecular characterization of a novel cytorhabdovirus with a unique genomic organization infecting yerba mate (Ilex paraguariensis) in Argentina

The genome of a novel rhabdovirus was detected in yerba mate (Ilex paraguariensis St. Hil.). The newly identified virus, tentatively named yerba mate virus A (YmVA), has a genome of 14,961 nucleotides. Notably, eight open reading frames were identified in the antigenomic orientation of the negative-sense, single-stranded viral RNA, including two novel accessory genes, in the order 3-N-P-3-4-M-G-L-8-5. Sequence identity of the encoded proteins as well as phylogenetic analysis suggest that YmVA is a new member of the genus Cytorhabdovirus, family Rhabdoviridae. YmVA unique genomic organization and phylogenetic relationships indicate that this virus likely represents a distinct evolutionary lineage within the cytorhabdoviruses.

microbiology↗

Bean yellow mosaic virus infecting broad bean in the green belt of Cordoba, Argentina

Broad bean (Vicia faba L) is the fourth most important pulse crop in the world. In Argentina, broad bean production was of 1,841 hectares and 16,500 tons during the 2017 growing season. Broad bean is commonly used in rotations; especially by farmers located in \"green belts\" that are peri-urban areas surrounding large cities that include horticultural family farms. Plants showing marked foliar mosaic symptoms, typical of viral infection, were collected during the 2015 growing season in the green belt of Cordoba city, Argentina. Preparations of symptomatic tissues were mechanically inoculated onto healthy broad bean plants in the greenhouse, which developed symptoms similar to those observed in the field. In addition, symptomatic samples were positive when tested by indirect ELISA with the anti-potyvirus group monoclonal antibody. Further, flexuous filamentous particles typical of potyviruses were observed under the electronic microscope on dip preparations. Lastly, total RNA was extracted from a symptomatic leaf and high-throughput sequenced, which allowed the assembly of a single virus sequence corresponding to a new highly divergent strain of Bean yellow mosaic virus (BYMV). Phylogenetic insights clustered this Argentinean broad bean isolate (BYMV-ARGbb) within group IX of BYMV. Given the economical importance of this virus and its associated disease, the results presented here are a pivotal first step oriented to explore the eventual incidence and epidemiological parameters of BYMV in broad bean in Argentina.

microbiology↗