Search bioRxiv⌕ Search

Biology subjects

Gomez-Talquenca, S.

Publications and source records attributed to Gomez-Talquenca, S..

5 recordsLinked to original sources

RNA virus discovery sheds light on the virome of a major vineyard pest, the European grapevine moth (Lobesia botrana)

The European grapevine moth (Lobesia botrana) poses a significant threat to vineyards worldwide, causing extensive economic losses. While its ecological interactions and control strategies are well-studied, its associated viral diversity remains unexplored. Here, we employ high-throughput sequencing data mining to comprehensively characterize the L. botrana virome, revealing novel and diverse RNA viruses. We characterized four new viral members belonging to distinct families, with evolutionary cues of cypoviruses (Reoviridae), sobemo-like viruses (Solemoviridae), phasmaviruses (Phasmaviridae), and carmotetraviruses (Carmotetraviridae). Phylogenetic analysis of the cypoviruses places them within the genus in affinity with other moth viruses, suggesting a potential ecological roles and host range within Lepidoptera. The bi-segmented and highly divergent sobemo-like virus showed a distinctive evolutionary trajectory of its encoding proteins at the periphery of recently reported invertebrate Sobelivirales. Notably, the presence of a novel phasmavirus, typically associated with mosquitoes, expands the known host range and diversity of this family to moths. Furthermore, the identification of a carmotetravirus branching in the same cluster of providence virus, a lepidopteran virus which replicates in plants, raises questions regarding the biological significance of this moth virus and grapevine. We further explored viral sequences in several publicly available transcriptomic datasets of the moth, indicating potential prevalence across distinct conditions. These results underscore the existence of a complex virome within L. botrana and lays the foundation for future studies investigating the ecological roles, evolutionary dynamics, and potential biocontrol applications of these viruses on the L. botrana--vineyard ecosystem.

microbiology↗

Diploid genome assembly of the Malbec grapevine cultivar enables haplotype-aware analysis of transcriptomic differences underlying clonal phenotypic variation

1.To preserve their varietal attributes, established grapevine cultivars (Vitis vinifera L. ssp. vinifera) must be clonally propagated, due to their highly heterozygous genomes. Malbec is a France-originated cultivar appreciated for producing high-quality wines, and is the offspring of cultivars Prunelard and Magdeleine Noire des Charentes. Here, we have built a diploid genome assembly of Malbec, after trio binning of PacBio long reads into the two haploid complements inherited from either parent. After haplotype-aware deduplication and corrections, complete assemblies for the two haplophases were obtained with very low haplotype switch-error rate (<0.025). The haplophases alignment identified >25% of polymorphic regions. Gene annotation including RNA-seq transcriptome assembly and ab initio prediction evidence resulted in similar gene model numbers for both haplophases. The annotated diploid assembly was exploited in the transcriptomic comparison of four clonal accessions of Malbec that exhibited variation in berry composition traits. Analysis of the ripening pericarp transcriptome using either haplophases as reference yielded similar results, although some differences were observed. Particularly, among the differentially expressed genes identified only with the Magdeleine-inherited haplotype as reference, we observed an over-representation of hypothetically hemizygous genes. The higher berry anthocyanin content of clonal accession 595 was associated with increased abscisic acid responses, possibly leading to the observed overexpression of phenylpropanoid metabolism genes and deregulation of genes associated to abiotic stress response. Overall, the results highlight the importance of producing diploid assemblies to fully represent the genomic diversity of highly heterozygous woody crop cultivars and to unveil the molecular bases of clonal phenotypic variation.

genomics↗

Clonal propagation history shapes the intra-cultivar genetic diversity in Malbec grapevines

Grapevine (Vitis vinifera L.) cultivars are clonally propagated to preserve their varietal attributes. However, novel genetic variation still accumulates due to somatic mutations. Aiming to study the potential impact of clonal propagation history on grapevines intra-cultivar genetic diversity, we have focused on Malbec. This cultivar is appreciated for red wines elaboration, it was originated in Southwestern France and introduced into Argentina during the 1850s. Here, we generated whole-genome resequencing data for four Malbec clones with different historical backgrounds. A stringent variant calling procedure was established to identify reliable clonal polymorphisms, additionally corroborated by Sanger sequencing. This analysis retrieved 941 single nucleotide variants (SNVs), occurring among the analyzed clones. Based on a set of validated SNVs, a genotyping experiment was custom-designed to survey Malbec genetic diversity. We successfully genotyped 214 samples and identified 14 different clonal genotypes, that clustered into two genetically divergent groups. Group-Ar was driven by clones with a long history of clonal propagation in Argentina, while Group-Fr was driven by clones that have longer remained in Europe. Findings show the ability of such approaches for clonal genotypes identification in grapevines. In particular, we provide evidence on how human actions may have shaped Malbec extant genetic diversity pattern.

genomics↗

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↗

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↗