Biology subjects

Rivero, R. M.

Publications and source records attributed to Rivero, R. M..

5 recordsLinked to original sources

bioRxiv2024

Bats from the Colombian Caribbean Reveal a new subtype of Influenza A (H18N12)

Influenza viruses have an excellent capacity for mutation and adaptation in mammalian hosts, which makes them viruses of medical and veterinary importance. Influenzaviruses have been studied mainly in birds but minor in bats. It is unknown whether Chiroptera are reservoirs of influenza viruses. However, circulation in bats showed molecular divergence from H17N10 (Guatemala) and H18N11 (Peru), and they were designated as new subtypes. The study aimed to characterize the influenza A virus detected in the fishing bat Noctilio albiventris. A surveillance study of pathogens of public health interest was carried out; rectal samples were taken from four fishing bats (N. albiventris) captured in Talaigua Nuevo, Bolivar, Colombia. The samples were sequenced by NGS using DNBseq (MGI-G50(R)) and analyzed with bioinformatics tools. Eight viral contigs associated with the Orthomyxoviridae family were obtained. The identified segments showed around 90% similarity with H18N11, except for the neuraminidase (N). The phylogenetic analysis of the N protein showed the appearance of a basal branch to the N11 subtype, and the molecular clock indicates that it does not share a recent common ancestor. 3D modeling indicates that the N protein of N. albiventris presents three mutations (K363R, T242K, and I139V) near the hypothetical active site of the protein. These mutations potentially increase the interaction with the HLA-DR of bats, which could have significant implications for the viruss behavior. The phylogenetic, evolutionary, and antigenic divergence of the N protein of N. albiventris suggests a new subtype called H18N12. Its role as a pathogen must be studied.

bioinformatics↗

bioRxiv2024

Multi-Omics Exploration of ABA Involvement in Identifying Unique Molecular Markers for Single and Combined Stresses in tomato plants

Over the past decade, our research group has found that plant responses to combined abiotic stresses are unique and cannot be inferred from studying plants exposed to individual stresses. Adaptive mechanisms involve changes in gene expression, ion regulation, hormonal balance, and metabolite biosynthesis or degradation. Understanding how these mechanisms integrate from stress perception to biochemical and physiological adjustments is a major challenge in abiotic stress signaling studies. Today, vast amounts of -omics data (genomics, transcriptomics, proteomics, metabolomics, phenomics) are readily available. Additonally, each -omic level is regulated and influenced by the others, highlighting the complexity of plant metabolisms response to stress. Considering abscisic acid (ABA) as a key regulator in plant abiotic stress responses, in our study, ABA-deficient plants (flc) exposed to single or combined salinity and heat stresses were evaluated and different -omics analyses were conducted. Significant changes in biomass, photosynthesis, ions, transcripts, and metabolites occurred in mutant plants under single or combined stresses. Exogenous ABA application in flc mutants did not fully recover plant phenotypes or metabolic levels but induced cellular reprogramming with changes in specific markers. Multi-omics analysis aimed to identify ABA-dependent, ABA-independent, or stress-dependent markers in plant responses to single or combined stresses. We demonstrated that studying different -omics together identifies specific markers for each stress condition not detectable individually. Our findings provide insight into specific metabolic markers in plant responses to single and combined stresses, highlighting specific regulation of metabolic pathways, ion absorption, and physiological responses crucial for plant tolerance to climate change. HighlightThe integration of different -omics has enabled the identification of specific ABA-dependent or -independent markers for single or combined abiotic stresses. These markers were not initially detectable when studying the different -omics individually.

plant biology↗

bioRxiv2023

Specific ABA-independent tomato transcriptome reprogramming under abiotic stress combination

Crops often have to face several abiotic stresses simultaneously, and under these conditions, the plants response significantly differs from that observed under a single stress. Nevertheless, most of the molecular markers identified for increasing plant stress tolerance have been characterized under single abiotic stresses, explaining their unexpected results when they are tested under real field conditions. One important regulator of the plants responses to abiotic stresses is ABA. The ABA signaling system engages many stress-responsive genes, however, many others do not respond to ABA treatments. Thus, the ABA-independent pathway, which is still largely unknown, involve multiple signaling pathways and important molecular components necessary for the plants adaptation to climate change. In the present study, tomato ABA-deficient mutants (flacca, flc) were subjected to salinity, heat, or their combination. A deep RNA-seq analysis revealed that the combination of salinity and heat induced an important reprogramming of the tomato transcriptome, and from the 685 genes that were specifically regulated under this combination in our flc mutants, 463 genes were regulated by ABA-independent systems. Among these genes, we identified 6 transcription factors (TFs) belonging to the R2R3MYB family that were significantly upregulated. A protein-protein interaction network showed that the TFs SlMYB50 and SlMYB86 were directly involved in the upregulation of the flavonol biosynthetic pathway-related genes. This is the first time that some important ABA-independent TFs involved in the specific plant response to abiotic stress combination have been identified. Considering that ABA levels dramatically change in response to environmental factors, the study of ABA-independent genes that are specifically regulated under stress combination may provide a marvelous tool for increasing plant resilience to climate change. SIGNIFICANCE STATEMENTThis study in tomato Wt and ABA-deficient mutant plants reveals a specific and unique ABA-independent transcriptome reprogramming under abiotic stress combination, with the identification of some key TFs that were induced under these specific conditions. Taking into account that ABA levels dramatically change in all crops in response to environmental factors, the study of ABA-independent genes that are specifically regulated under stress combination may provide a marvelous tool for increasing plant resilience to climate change.

plant biology↗

bioRxiv2020

Fruit presence induces polar auxin transport in citrus and olive stem and represses hormone release from the bud

In many fruit trees, heavy fruit load in one year reduces flowering in the following year, creating a biennial fluctuation in yield termed alternate bearing (AB). In subtropical trees, where flowering induction is mostly governed by the accumulation of cold hours, fruit load is thought to generate a signal (AB signal) that blocks the perception of the cold induction. Fruit removal during a heavy-fruit-load year (On-Crop) is effective at inducing flowering only if performed one to a few months prior to onset of the flowering-induction period. We previously showed that following fruit removal, content of the auxin indoleacetic acid (IAA) in citrus buds is reduced, suggesting that the hormone plays a role in the AB signal. Here, we demonstrate that fruit presence generates relatively strong polar auxin transport (PAT) in citrus and olive stems. Upon fruit removal, PAT is reduced and allows auxin release from the bud. Furthermore, using immunolocalization, hormone and gene expression analyses, we show that in citrus, IAA level in the bud and, specifically, in the apical meristem is reduced upon fruit removal. Overall, our data provide support for the notion that fruit presence generates an auxin signal in the bud which may affect flowering induction. HIGHLIGHTSHeavy fruit load can reduce flowering intensity the following year. Fruit presence, inducing polar auxin transport in stems and inhibiting auxin release from buds, may be a fruit-load signal.

plant biology↗

bioRxiv2020

Synchronization and interaction of proline, ascorbate and oxidative stress pathways under abiotic stress combination in tomato plants

ABSTRACTAdverse environmental conditions have a devastating impact on plant productivity. In nature, multiple abiotic stresses occur simultaneously, and plants have evolved unique responses to cope against this combination of stresses. Here, we coupled genome-wide transcriptional profiling and untargeted metabolomics with physiological and biochemical analyses to characterize the effect of salinity and heat applied in combination on the metabolism of tomato plants. Our results demonstrate that this combination of stresses causes a unique reprogramming of metabolic pathways, including changes in the expression of 1,388 genes and the accumulation of 568 molecular features. Pathway enrichment analysis of transcript and metabolite data indicated that the proline and ascorbate pathways act synchronously to maintain cellular redox homeostasis, which was supported by measurements of enzymatic activity and oxidative stress markers. We also identified key transcription factors from the basic Leucine Zipper Domain (bZIP), Zinc Finger Cysteine-2/Histidine-2 (C2H2) and Trihelix families that are likely regulators of the identified up-regulated genes under salinity+heat combination. Our results expand the current understanding of how plants acclimate to environmental stresses in combination and unveils the synergy between key cellular metabolic pathways for effective ROS detoxification. Our study opens the door to elucidating the different signaling mechanisms for stress tolerance.HIGHLIGHTSThe combination of salinity and heat causes a unique reprogramming of tomato metabolic pathways by changing the expression of specific genes and metabolic features.Proline and ascorbate pathways act synchronously to maintain cellular redox homeostasisKey transcription factors from the basic Leucine Zipper Domain (bZIP), Zinc Finger Cysteine-2/Histidine-2 (C2H2) and Trihelix families were identified as putative regulators of the identified up-regulated genes under salinity and heat combination.View Full Text

plant biology↗