Biology subjects

Zavallo, D.

Publications and source records attributed to Zavallo, D..

5 recordsLinked to original sources

bioRxiv2026

Enhanced Viral Detection in Grapevine via Exome Depletion and Next-Generation Sequencing (NGS)

Grapevine (Vitis vinifera L.) is highly prone to viral infections that pose a significant threat to global viticulture sustainability. Traditional detection methods, such as PCR and ELISA, are limited to well-known pathogens, highlighting the need for more comprehensive and unbiased approaches. Here, we present the development of a cost-effective viral enrichment system adapted to next-generation sequencing (NGS) for the detection and characterization of grapevine viruses. Our strategy leverages hybridization-based capture using biotin-labeled cDNA probes hereafter named "Chloro-Zero") designed to selectively deplete highly abundant host transcripts particularly plastid and ribosomal RNAs while preserving viral RNA. Probe design was informed by transcriptomic analysis of V. vinifera. We evaluated different subtractor-to-target RNA ratios, observing a consistent reduction of host RNA and a moderate enrichment of viral sequences. NGS analysis revealed improved recovery of low-abundance viral transcripts, with coverage levels comparable, to a certain extent, to those obtained using previously available commercial kits, but at a significantly lower cost. Although variability in depletion efficiency was observed, the results demonstrate the potential of this scalable and locally adaptable protocol for virome profiling in grapevines. By addressing key limitations of current depletion methods, our approach facilitates the detection of emerging viral threats and supports the development of more effective certification programs and sustainable management practices. Ongoing improvements in probe design and bioinformatic workflows are expected to enhance performance, providing a robust platform for broader applications in plant virology.

plant biology↗

bioRxiv2020

A New World begomovirus infecting Grapevine

Cotton (Gossypium spp.) is a globally significant cash crop cultivated for its versatile fiber, widely used in the textile industry. Cotton, as other crops, is vulnerable to infectious pathogens. Several of them, including viruses, are a major threat to cotton production. Geminiviruses (family Geminiviridae) are insect transmitted, small non-enveloped viruses, with circular single-stranded DNA genomes, which are encapsidated in quasi-icosahedral geminated virions. Here we present evidence of a novel begomovirus (genus Begomovirus) infecting cotton from Argentina. Two circular ssDNA virus sequences were assembled from high-throughput sequencing data from Gossyipium hirsutum cotton samples showing mosaic symptoms from Argentina. Structural and functional annotation indicated that the virus sequences corresponded to complete DNA components A and B of a novel New World bipartite begomovirus. Genetic distance and evolutionary analyses support that the detected sequences correspond to a new virus, a tentative prototype member of a novel species which we propose the name "Cotton mosaic virus" (CoMV).

microbiology↗

bioRxiv2020

RdDM pathway is required for Tobamovirus-induced symptomatology production

O_LISmall RNAs (sRNA) are important molecules for gene regulation in plants and play an essential role in plant-pathogen interactions. Researchers have evaluated the relationship between viral infections as well as the endogenous accumulation of sRNAs and the transcriptional changes associated with the production of symptoms, little is known about a possible direct role of epigenetics, mediated by 24-nt sRNAs, in the induction of these symptoms. C_LIO_LIWith the use of different RNA directed DNA methylation pathway mutants and triple demethylase mutants, here we demonstrate that the disruption of RdDM pathway during viral infection produced alterations in the plant transcriptomic changes (because of the infection) and in symptomatology. C_LIO_LIThis study represents the initial step in exposing that DNA methylation directed by endogenous sRNAs has an important role, uncoupled to defense, in the production of symptoms associated with plant-virus interactions. C_LI Significance statementThe crop yield losses induced by phytoviruses are mainly associated with the symptoms of the disease. DNA modifications as methylation, can modulate the information coded by the sequence, process named epigenetics. Viral infection can change the expression patterns of different genes linked to defenses and symptoms. This work represents the initial step to expose the role of epigenetic process, in the production of symptoms associated with plants-virus interactions.

plant biology↗

bioRxiv2019

Genomic re-assessment of the transposable element landscape of the potato genome

Transposable elements (TEs) are DNA sequences with the ability to auto-replicate and move throughout the host genome. TEs are major drivers in stress response and genome evolution. Given their significance, the development of clear and efficient TE annotation pipelines has become essential for many species. The latest de novo TE discovery tools, along with available TEs from Repbase and sRNA-seq data, allowed us to perform a reliable potato TEs detection, classification and annotation through an open-source and freely available pipeline (https://github.com/DiegoZavallo/TE_Discovery). Using a variety of tools, approaches and rules, our pipeline revealed that ca. 16% of the potato genome can be clearly annotated as TEs. Additionally, we described the distribution of the different types of TEs across the genome, where LTRs and MITEs present a clear clustering pattern in pericentromeric and subtelomeric/telomeric regions respectively. Finally, we analyzed the insertion age and distribution of LTR retrotransposon families which display a distinct pattern between the two major superfamilies. While older Gypsy elements concentrated around heterochromatic regions, younger Copia elements located predominantly on euchromatic regions. Overall, we delivered not only a reliable, ready-to-use potato TE annotation files, but also all the necessary steps to perform de novo detection for other species. Key MessageWe provide a comprehensive and reliable potato TE landscape, based on a wide variety of identification tools and integrative approaches, producing clear and ready-to-use outputs for the scientific community.

plant biology↗

bioRxiv2018

Evidence of a Novel Vitivirus in Grapevine cv Riesling

Vitivirus are ssRNA(+) viruses in the family Betaflexiviridae (subfamily Trivirinae). There are currently ten ICTV recognized virus species in the genus; nevertheless, the extended use of NGS technologies is rapidly expanding their diversity and six more have been proposed recently. Here, we present the characterization of a novel virus from grapevines, which fits the genomic architecture and evolutionary constraints to be classifiable within the Vitivirus genus. The detected virus sequence is 7,607 nt long, including a typical genome organization of ORFs encoding a replicase (RP), a 22 kDa protein, a movement protein, a coat protein (CP) and a nucleic acid binding protein. Here, we present the characterization of a novel virus from grapevines. Phylogenetic analyses based on the predicted RP and CP protein unequivocally places the new virus within the Vitivirus genus. Multiple independent RNAseq data confirmed the presence of the detected virus in berries at diverse developmental stages. Additionally, we detected, confirmed, and assembled virus sequences from grapevine samples of distinct cultivars from America, Europe, Asia and Oceania, sharing 74.9%-97.9% nt identity, suggesting that the identified virus is widely distributed and diverse. We propose the name grapevine virus L (GVL) to the detected Vitivirus.

plant biology↗