Biology subjects

Asurmendi, S.

Publications and source records attributed to Asurmendi, S..

7 recordsLinked to original sources

bioRxiv2025

A viral infection reshapes Arabidopsis water management via root hydraulics, aquaporin downregulation and osmotic adjustment

The effect of plant viruses on root water relations and on how roots and shoots coordinate under infection remains poorly understood. Using a hydroponic Arabidopsis thaliana-Turnip mosaic virus (TuMV) pathosystem, we integrated biometric, anatomical, hydraulic, and gas-exchange measurements to dissect how viral infection reshapes root-shoot water relations. TuMV impaired root development, as reflected by an early plateau of primary root elongation. At the functional level, infected plants exhibited a decrease in root hydraulic conductance per unit root mass, concomitant with transcriptional downregulation of root aquaporin genes. Despite this, the relative contribution of aquaporin-mediated water transport, assessed via sodium azide inhibition, remained unchanged, indicating that the virus downregulates total hydraulic capacity without altering the apoplastic-symplastic partitioning of water flow. Gas-exchange analysis revealed a virus-induced decoupling between stomatal conductance and net CO2 assimilation, resulting in a non-adaptive increase in intrinsic water-use efficiency. This loss of photosynthetic plasticity, combined with shoot-localized osmotic adjustment (more negative leaf osmotic potential and higher relative water content), points to a constrained, suboptimal physiological state. Multivariate analysis confirmed that variation in physiological traits largely drives phenotypic divergence between treatments. Together, these coordinated alterations, reduced root hydraulics, rigid gas-exchange relationships and passive hydraulic matching to a stunted shoot, depict plants locked into a low-performance equilibrium, poorly equipped to compete for water and carbon. This work reveals a systemic hydraulic-photosynthetic reconfiguration that could account for compromises in plant resilience and resource competitiveness. HighlightTuMV infection induces a coordinated whole-plant hydraulic reconfiguration characterized by premature growth arrest, reduced root hydraulic conductance, and decoupling of stomatal conductance from photosynthesis, resulting in a constrained physiological state.

plant biology↗

bioRxiv2021

TuMV infection alters miR168/AGO1 and miR403/AGO2 systems regulation in Arabidopsis

Plant Argonaute proteins, chiefly AGO1 and 2, restrict viral infections. AGO1/2 also participate in developmental processes and are tightly regulated by microRNAs. Under viral infections, the regulatory loop comprising miR168/AGO1 is well studied, but much less so the miR403/AGO2 system. We studied both regulatory systems in TuMV-infected Arabidopsis plants. TuMV downregulated miRNAs precursor molecules, but mature miRNAs overaccumulated, without evidence of transcriptional alteration. AGO1 protein remained at basal levels whereas AGO2 overaccumulated. These results are in line with previous reports studying abiotic and biotic impact on microRNA biogenesis and AGO-dependent antiviral defense, expanding our knowledge of the miR403/AGO2 regulatory system.

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↗

bioRxiv2017

Arabidopsis phenotyping through Geometric Morphometrics

In recent years, much technical progress has been done regarding plant phenotyping including the model species Arabidopsis thaliana. With automated, high-throughput platforms and the development of improved algorithms for the rosette segmentation task, it is now possible to massively extract reliable shape and size parameters for genetic, physiological and environmental studies. The development of low-cost phenotyping platforms and freeware resources make it possible to widely expand phenotypic analysis tools for Arabidopsis. However, objective descriptors of shape parameters that could be used independently of platform and segmentation software used are still lacking and shape descriptions still rely on ad hoc or even sometimes contradictory descriptors, which could make comparisons difficult and perhaps inaccurate. Modern geometric morphometrics is a family of methods in quantitative biology proposed to be the main source of data and analytical tools in the emerging field of phenomics studies. It has been used for taxonomists and paleontologists for decades and is now a mature discipline. By combining geometry, multivariate analysis and powerful statistical techniques, it offers the possibility to reproducibly and accurately account for shape variations amongst groups. Based on the location of homologous landmarks points over photographed or scanned specimens, these tools could identify the existence and degree of shape variation and measure them in standard units. Here, it is proposed a particular scheme of landmarks placement on Arabidopsis rosette images to study shape variation in the case study of viral infection processes. Several freeware-based geometric morphometric tools are applied in order to exemplify the usefulness of this approach to the study of phenotypes in this model plant. These methods are concisely presented and explained. Shape differences between controls and infected plants are quantified throughout the infectious process and visualized with the appealing graphs that are a hallmark of these techniques and render complex mathematical analysis simple outcomes to interpret. Quantitative comparisons between two unrelated ssRNA+ viruses are shown and reproducibility issues are assessed. Combined with the newest automatons and plant segmentation procedures, geometric morphometric tools could boost phenotypic features extraction and processing in an objective, reproducible manner.

plant biology↗