RESUMO
Despite considerable efforts, the mechanisms linking genomic alterations to the transcriptional identity of cancer cells remain elusive. Integrative genomic analysis, using a network-based approach, identified 407 master regulator (MR) proteins responsible for canalizing the genetics of individual samples from 20 cohorts in The Cancer Genome Atlas (TCGA) into 112 transcriptionally distinct tumor subtypes. MR proteins could be further organized into 24 pan-cancer, master regulator block modules (MRBs), each regulating key cancer hallmarks and predictive of patient outcome in multiple cohorts. Of all somatic alterations detected in each individual sample, >50% were predicted to induce aberrant MR activity, yielding insight into mechanisms linking tumor genetics and transcriptional identity and establishing non-oncogene dependencies. Genetic and pharmacological validation assays confirmed the predicted effect of upstream mutations and MR activity on downstream cellular identity and phenotype. Thus, co-analysis of mutational and gene expression profiles identified elusive subtypes and provided testable hypothesis for mechanisms mediating the effect of genetic alterations.
Assuntos
Neoplasias/genética , Transcrição Gênica , Adenocarcinoma/genética , Animais , Linhagem Celular Tumoral , Neoplasias do Colo/genética , Regulação Neoplásica da Expressão Gênica , Redes Reguladoras de Genes , Genoma Humano , Células HEK293 , Humanos , Camundongos Nus , Mutação/genética , Reprodutibilidade dos TestesRESUMO
Trehalose 6-phosphate (Tre6P) is an essential signal metabolite that regulates the level of sucrose, linking growth and development to the metabolic status. We hypothesized that Tre6P plays a role in mediating the regulation of gene expression by sucrose. To test this, we performed transcriptomic profiling on Arabidopsis (Arabidopsis thaliana) plants that expressed a bacterial TREHALOSE 6-PHOSPHATE SYNTHASE (TPS) under the control of an ethanol-inducible promoter. Induction led to a 4-fold rise in Tre6P levels, a concomitant decrease in sucrose, significant changes (FDR ≤ 0.05) of over 13,000 transcripts, and 2-fold or larger changes of over 5,000 transcripts. Comparison with nine published responses to sugar availability allowed some of these changes to be linked to the rise in Tre6P, while others were probably due to lower sucrose or other indirect effects. Changes linked to Tre6P included repression of photosynthesis-related gene expression and induction of many growth-related processes including ribosome biogenesis. About 500 starvation-related genes are known to be induced by SUCROSE-NON-FERMENTING-1-RELATED KINASE 1 (SnRK1). They were largely repressed by Tre6P in a manner consistent with SnRK1 inhibition by Tre6P. SnRK1 also represses many genes that are involved in biosynthesis and growth. These responded to Tre6P in a more complex manner, pointing toward Tre6P interacting with other C-signaling pathways. Additionally, elevated Tre6P modified the expression of genes encoding regulatory subunits of the SnRK1 complex and TPS class II and FCS-LIKE ZINC FINGER proteins that are thought to modulate SnRK1 function and genes involved in circadian, TARGET OF RAPAMYCIN, light, abscisic acid, and other hormone signaling.
Assuntos
Arabidopsis , Regulação da Expressão Gênica de Plantas , Glucosiltransferases , Sacarose , Fosfatos Açúcares , Transcriptoma , Trealose , Arabidopsis/genética , Arabidopsis/metabolismo , Fosfatos Açúcares/metabolismo , Trealose/análogos & derivados , Trealose/metabolismo , Sacarose/metabolismo , Transcriptoma/genética , Glucosiltransferases/metabolismo , Glucosiltransferases/genética , Perfilação da Expressão Gênica , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Plantas Geneticamente Modificadas , Transdução de SinaisRESUMO
Substance use disorders (SUD) and drug addiction are major threats to public health, impacting not only the millions of individuals struggling with SUD, but also surrounding families and communities. One of the seminal challenges in treating and studying addiction in human populations is the high prevalence of co-morbid conditions, including an increased risk of contracting a human immunodeficiency virus (HIV) infection. Of the ~15 million people who inject drugs globally, 17% are persons with HIV. Conversely, HIV is a risk factor for SUD because chronic pain syndromes, often encountered in persons with HIV, can lead to an increased use of opioid pain medications that in turn can increase the risk for opioid addiction. We hypothesize that SUD and HIV exert shared effects on brain cell types, including adaptations related to neuroplasticity, neurodegeneration, and neuroinflammation. Basic research is needed to refine our understanding of these affected cell types and adaptations. Studying the effects of SUD in the context of HIV at the single-cell level represents a compelling strategy to understand the reciprocal interactions among both conditions, made feasible by the availability of large, extensively-phenotyped human brain tissue collections that have been amassed by the Neuro-HIV research community. In addition, sophisticated animal models that have been developed for both conditions provide a means to precisely evaluate specific exposures and stages of disease. We propose that single-cell genomics is a uniquely powerful technology to characterize the effects of SUD and HIV in the brain, integrating data from human cohorts and animal models. We have formed the Single-Cell Opioid Responses in the Context of HIV (SCORCH) consortium to carry out this strategy.
RESUMO
Cell surface proteins have been used as diagnostic and prognostic markers in cancer research and as targets for the development of anticancer agents. Many of these proteins lie at the top of signaling cascades regulating cell responses and gene expression, therefore acting as 'signaling hubs'. It has been previously demonstrated that the integrated network analysis on transcriptomic data is able to infer cell surface protein activity in breast cancer. Such an approach has been implemented in a publicly available method called 'SURFACER'. SURFACER implements a network-based analysis of transcriptomic data focusing on the overall activity of curated surface proteins, with the final aim to identify those proteins driving major phenotypic changes at a network level, named surface signaling hubs. Here, we show the ability of SURFACER to discover relevant knowledge within and across cancer datasets. We also show how different cancers can be stratified in surface-activity-specific groups. Our strategy may identify cancer-wide markers to design targeted therapies and biomarker-based diagnostic approaches.
Assuntos
Antineoplásicos , Neoplasias da Mama , Antineoplásicos/uso terapêutico , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/metabolismo , Neoplasias da Mama/metabolismo , Feminino , Humanos , Proteínas de Membrana/genética , TranscriptomaRESUMO
Aspartate-glutamate carrier isoform 1 (AGC1) is a carrier responsible for the export of mitochondrial aspartate in exchange for cytosolic glutamate and is part of the malate-aspartate shuttle, essential for the balance of reducing equivalents in the cells. In the brain, mutations in SLC25A12 gene, encoding for AGC1, cause an ultra-rare genetic disease, reported as a neurodevelopmental encephalopathy, whose symptoms include global hypomyelination, arrested psychomotor development, hypotonia and seizures. Among the biological components most affected by AGC1 deficiency are oligodendrocytes, glial cells responsible for myelination processes, and their precursors [oligodendrocyte progenitor cells (OPCs)]. The AGC1 silencing in an in vitro model of OPCs was documented to cause defects of proliferation and differentiation, mediated by alterations of histone acetylation/deacetylation. Disrupting AGC1 activity could possibly reduce the availability of acetyl groups, leading to perturbation of many biological pathways, such as histone modifications and fatty acids formation for myelin production. Here, we explore the transcriptome of mouse OPCs partially silenced for AGC1, reporting results of canonical analyses (differential expression) and pathway enrichment analyses, which highlight a disruption in fatty acids synthesis from both a regulatory and enzymatic stand. We further investigate the cellular effects of AGC1 deficiency through the identification of most affected transcriptional networks and altered alternative splicing. Transcriptional data were integrated with differential metabolite abundance analysis, showing downregulation of several amino acids, including glutamine and aspartate. Taken together, our results provide a molecular foundation for the effects of AGC1 deficiency in OPCs, highlighting the molecular mechanisms affected and providing a list of actionable targets to mitigate the effects of this pathology.
Assuntos
Sistemas de Transporte de Aminoácidos Acídicos/deficiência , Antiporters/deficiência , Doenças Desmielinizantes Hereditárias do Sistema Nervoso Central , Doenças Mitocondriais , Células Precursoras de Oligodendrócitos , Transtornos Psicomotores , Camundongos , Animais , Regulação para Baixo/genética , Células Precursoras de Oligodendrócitos/metabolismo , Ácido Aspártico/metabolismo , Isoformas de Proteínas/metabolismo , Ácidos GraxosRESUMO
The current outbreak of COVID-19 has generated an unprecedented scientific response worldwide, with the generation of vast amounts of publicly available epidemiological, biological and clinical data. Bioinformatics scientists have quickly produced online methods to provide non-computational users with the opportunity of analyzing such data. In this review, we report the results of this effort, by cataloguing the currently most popular web tools for COVID-19 research and analysis. Our focus was driven on tools drawing data from the fields of epidemiology, genomics, interactomics and pharmacology, in order to provide a meaningful depiction of the current state of the art of COVID-19 online resources.
Assuntos
COVID-19/prevenção & controle , Pandemias , COVID-19/virologia , Biologia Computacional , Humanos , Internet , SARS-CoV-2/isolamento & purificaçãoRESUMO
The global crisis of opioid overdose fatalities has led to an urgent search to discover the neurobiological mechanisms of opioid use disorder (OUD). A driving force for OUD is the dysphoric and emotionally painful state (hyperkatifeia) that is produced during acute and protracted opioid withdrawal. Here, we explored a mechanistic role for extrahypothalamic stress systems in driving opioid addiction. We found that glucocorticoid receptor (GR) antagonism with mifepristone reduced opioid addiction-like behaviors in rats and zebrafish of both sexes and decreased the firing of corticotropin-releasing factor neurons in the rat amygdala (i.e., a marker of brain stress system activation). In support of the hypothesized role of glucocorticoid transcriptional regulation of extrahypothalamic GRs in addiction-like behavior, an intra-amygdala infusion of an antisense oligonucleotide that blocked GR transcriptional activity reduced addiction-like behaviors. Finally, we identified transcriptional adaptations of GR signaling in the amygdala of humans with OUD. Thus, GRs, their coregulators, and downstream systems may represent viable therapeutic targets to treat the "stress side" of OUD.
Assuntos
Transtornos Relacionados ao Uso de Opioides , Síndrome de Abstinência a Substâncias , Corticosteroides , Animais , Hormônio Liberador da Corticotropina , Ratos , Peixe-ZebraRESUMO
MOTIVATION: Despite widespread prevalence of somatic structural variations (SVs) across most tumor types, understanding of their molecular implications often remains poor. SVs are extremely heterogeneous in size and complexity, hindering the interpretation of their pathogenic role. Tools integrating large SV datasets across platforms are required to fully characterize the cancer's somatic landscape. RESULTS: svpluscnv R package is a swiss army knife for the integration and interpretation of orthogonal datasets including copy number variant segmentation profiles and sequencing-based structural variant calls. The package implements analysis and visualization tools to evaluate chromosomal instability and ploidy, identify genes harboring recurrent SVs and detects complex rearrangements such as chromothripsis and chromoplexia. Further, it allows systematic identification of hot-spot shattered genomic regions, showing reproducibility across alternative detection methods and datasets. AVAILABILITY AND IMPLEMENTATION: https://github.com/ccbiolab/svpluscnv. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.
Assuntos
Genoma , Genômica , Variações do Número de Cópias de DNA , Variação Estrutural do Genoma , Humanos , Reprodutibilidade dos Testes , Análise de Sequência , SoftwareRESUMO
The Metabolome and Transcriptome are mutually communicating within cancer cells, and this interplay is translated into the existence of quantifiable correlation structures between gene expression and metabolite abundance levels. Studying these correlations could provide a novel venue of understanding cancer and the discovery of novel biomarkers and pharmacological strategies, as well as laying the foundation for the prediction of metabolite quantities by leveraging information from the more widespread transcriptomics data. In the current paper, we investigate the correlation between gene expression and metabolite levels in the Cancer Cell Line Encyclopedia dataset, building a direct correlation network between the two molecular ensembles. We show that a metabolite/transcript correlation network can be used to predict metabolite levels in different samples and datasets, such as the NCI-60 cancer cell line dataset, both on a sample-by-sample basis and in differential contrasts. We also show that metabolite levels can be predicted in principle on any sample and dataset for which transcriptomics data are available, such as the Cancer Genome Atlas (TCGA).
Assuntos
Neoplasias , Transcriptoma , Biomarcadores , Linhagem Celular Tumoral , Humanos , Metaboloma/genética , Metabolômica , Neoplasias/genéticaRESUMO
Plants need to attune their stress responses to the ongoing developmental programmes to maximize their efficacy. For instance, successful submergence adaptation is often associated with a delicate balance between saving resources and their expenditure to activate measures that allow stress avoidance or attenuation. We observed a significant decrease in submergence tolerance associated with ageing in Arabidopsis thaliana, with a critical step between 2 and 3 weeks of post-germination development. This sensitization to flooding was concomitant with the transition from juvenility to adulthood. Transcriptomic analyses indicated that a group of genes related to abscisic acid and oxidative stress response was more highly expressed in juvenile plants than in adult ones. These genes are induced by the endomembrane tethered transcription factor ANAC017 that was in turn activated by submergence-associated oxidative stress. A combination of molecular, biochemical and genetic analyses showed that these genes are located in genomic regions that move towards a heterochromatic state with adulthood, as marked by lysine 4 trimethylation of histone H3. We concluded that, while the mechanisms of flooding stress perception and signal transduction were unaltered between juvenile and adult phases, the sensitivity that these mechanisms set into action is integrated, via epigenetic regulation, into the developmental programme of the plant.
Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/genética , Epigênese Genética , Oxigênio/metabolismo , Fatores de Transcrição/metabolismo , Ácido Abscísico/metabolismo , Adaptação Fisiológica , Arabidopsis/fisiologia , Proteínas de Arabidopsis/genética , Perfilação da Expressão Gênica , Germinação , Estresse Oxidativo , Reguladores de Crescimento de Plantas/metabolismo , Plantas Geneticamente Modificadas , Estresse Fisiológico , Fatores de Transcrição/genéticaRESUMO
MOTIVATION: Gene network inference and master regulator analysis (MRA) have been widely adopted to define specific transcriptional perturbations from gene expression signatures. Several tools exist to perform such analyses but most require a computer cluster or large amounts of RAM to be executed. RESULTS: We developed corto, a fast and lightweight R package to infer gene networks and perform MRA from gene expression data, with optional corrections for copy-number variations and able to run on signatures generated from RNA-Seq or ATAC-Seq data. We extensively benchmarked it to infer context-specific gene networks in 39 human tumor and 27 normal tissue datasets. AVAILABILITY AND IMPLEMENTATION: Cross-platform and multi-threaded R package on CRAN (stable version) https://cran.r-project.org/package=corto and Github (development release) https://github.com/federicogiorgi/corto. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.
Assuntos
Redes Reguladoras de Genes , Neoplasias , Humanos , Software , TranscriptomaRESUMO
SUMMARY: A primary problem in high-throughput genomics experiments is finding the most important genes involved in biological processes (e.g. tumor progression). In this applications note, we introduce spathial, an R package for navigating high-dimensional data spaces. spathial implements the Principal Path algorithm, which is a topological method for locally navigating on the data manifold. The package, together with the core algorithm, provides several high-level functions for interpreting the results. One of the analyses we propose is the extraction of the genes that are mainly involved in the progress from one state to another. We show a possible application in the context of tumor progression using RNA-Seq and single-cell datasets, and we compare our results with two commonly used algorithms, edgeR and monocle3, respectively. AVAILABILITY AND IMPLEMENTATION: The R package spathial is available on the Comprehensive R Archive Network (https://cran.r-project.org/web/packages/spathial/index.html) and on GitHub (https://github.com/erikagardini/spathial). It is distributed under the GNU General Public License (version 3). SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.
Assuntos
Algoritmos , Software , Evolução Biológica , GenômicaRESUMO
Several severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants have emerged, posing a renewed threat to coronavirus disease 2019 containment and to vaccine and drug efficacy. In this study, we analyzed more than 1,000,000 SARS-CoV-2 genomic sequences deposited up to April 27, 2021, on the GISAID public repository, and identified a novel T478K mutation located on the SARS-CoV-2 Spike protein. The mutation is structurally located in the region of interaction with human receptor ACE2 and was detected in 11,435 distinct cases. We show that T478K has appeared and risen in frequency since January 2021, predominantly in Mexico and the United States, but we could also detect it in several European countries.
Assuntos
COVID-19/virologia , Genoma Viral , SARS-CoV-2/genética , Glicoproteína da Espícula de Coronavírus/fisiologia , Europa (Continente) , Humanos , México , Mutação , Filogenia , Glicoproteína da Espícula de Coronavírus/genética , Estados UnidosRESUMO
The avalanche of genomic data generated from the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus requires the development of tools to detect and monitor its mutations across the world. Here, we present a webtool, coronapp, dedicated to easily processing user-provided SARS-CoV-2 genomic sequences and visualizing the current worldwide status of SARS-CoV-2 mutations. The webtool allows users to highlight mutations and categorize them by frequency, country, genomic location and effect on protein sequences, and to monitor their presence in the population over time. The tool is available at http://giorgilab.unibo.it/coronannotator/ for the annotation of user-provided sequences. The full code is freely shared at https://github.com/federicogiorgi/giorgilab/tree/master/coronannotator.
Assuntos
Genoma Viral , Mutação , SARS-CoV-2/genética , Sequência de Aminoácidos , COVID-19/virologia , Genômica , HumanosRESUMO
Pulpitis, inflammation of the dental pulp, is a disease that often necessitates emergency dental care. While pulpitis is considered to be a microbial disease primarily caused by bacteria, viruses have also been implicated in its pathogenesis. Here, we determined the expression of the SARS-CoV2 receptor, angiotensin converting enzyme 2 (ACE2) and its associated cellular serine protease TPMRSS2 in the dental pulp under normal and inflamed conditions. Next, we explored the relationship between the SARS-CoV-2/human interactome and genes expressed in pulpitis. Using existing datasets we show that both ACE2 and TPMRSS2 are expressed in the dental pulp and, that their expression does not change under conditions of inflammation. Furthermore, Master Regulator Analysis of the SARS-CoV2/human interactome identified 75 relevant genes whose expression values are either up-regulated or down-regulated in both the human interactome and pulpitis. Our results suggest that the dental pulp is vulnerable to SARS-CoV2 infection and that SARS-CoV-2 infection of the dental pulp may contribute to worse outcomes of pulpitis.
Assuntos
Infecções por Coronavirus/complicações , Polpa Dentária/metabolismo , Pneumonia Viral/complicações , Pulpite/virologia , Enzima de Conversão de Angiotensina 2 , Betacoronavirus/metabolismo , COVID-19 , Infecções por Coronavirus/metabolismo , Infecções por Coronavirus/virologia , Conjuntos de Dados como Assunto , Polpa Dentária/virologia , Perfilação da Expressão Gênica , Regulação da Expressão Gênica , Humanos , Pandemias , Peptidil Dipeptidase A/metabolismo , Pneumonia Viral/metabolismo , Pneumonia Viral/virologia , Pulpite/metabolismo , Receptores de Coronavírus , Receptores Virais/metabolismo , SARS-CoV-2 , Serina Endopeptidases/metabolismoRESUMO
There is a rising global concern for the recently emerged novel coronavirus (2019-nCoV). Full genomic sequences have been released by the worldwide scientific community in the last few weeks to understand the evolutionary origin and molecular characteristics of this virus. Taking advantage of all the genomic information currently available, we constructed a phylogenetic tree including also representatives of other coronaviridae, such as Bat coronavirus (BCoV) and severe acute respiratory syndrome. We confirm high sequence similarity (>99%) between all sequenced 2019-nCoVs genomes available, with the closest BCoV sequence sharing 96.2% sequence identity, confirming the notion of a zoonotic origin of 2019-nCoV. Despite the low heterogeneity of the 2019-nCoV genomes, we could identify at least two hypervariable genomic hotspots, one of which is responsible for a Serine/Leucine variation in the viral ORF8-encoded protein. Finally, we perform a full proteomic comparison with other coronaviridae, identifying key aminoacidic differences to be considered for antiviral strategies deriving from previous anti-coronavirus approaches.
Assuntos
Betacoronavirus/genética , Infecções por Coronavirus/virologia , Variação Genética , Genoma Viral , Sequência de Aminoácidos , Animais , Sequência de Bases , Betacoronavirus/classificação , COVID-19 , Quirópteros/virologia , Humanos , Modelos Genéticos , Filogenia , Pneumonia Viral , Proteoma , RNA Viral/genética , SARS-CoV-2RESUMO
UNLABELLED: The accurate reconstruction of gene regulatory networks from large scale molecular profile datasets represents one of the grand challenges of Systems Biology. The Algorithm for the Reconstruction of Accurate Cellular Networks (ARACNe) represents one of the most effective tools to accomplish this goal. However, the initial Fixed Bandwidth (FB) implementation is both inefficient and unable to deal with sample sets providing largely uneven coverage of the probability density space. Here, we present a completely new implementation of the algorithm, based on an Adaptive Partitioning strategy (AP) for estimating the Mutual Information. The new AP implementation (ARACNe-AP) achieves a dramatic improvement in computational performance (200× on average) over the previous methodology, while preserving the Mutual Information estimator and the Network inference accuracy of the original algorithm. Given that the previous version of ARACNe is extremely demanding, the new version of the algorithm will allow even researchers with modest computational resources to build complex regulatory networks from hundreds of gene expression profiles. AVAILABILITY AND IMPLEMENTATION: A JAVA cross-platform command line executable of ARACNe, together with all source code and a detailed usage guide are freely available on Sourceforge (http://sourceforge.net/projects/aracne-ap). JAVA version 8 or higher is required. CONTACT: califano@c2b2.columbia.edu SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.
Assuntos
Algoritmos , Biologia Computacional/métodos , Redes Reguladoras de Genes , Genética Reversa/métodos , Biologia de Sistemas , SoftwareRESUMO
MOTIVATION: Multiplex readout assays are now increasingly being performed using microfluidic automation in multiwell format. For instance, the Library of Integrated Network-based Cellular Signatures (LINCS) has produced gene expression measurements for tens of thousands of distinct cell perturbations using a 384-well plate format. This dataset is by far the largest 384-well gene expression measurement assay ever performed. We investigated the gene expression profiles of a million samples from the LINCS dataset and found that the vast majority (96%) of the tested plates were affected by a significant 2D spatial bias. RESULTS: Using a novel algorithm combining spatial autocorrelation detection and principal component analysis, we could remove most of the spatial bias from the LINCS dataset and show in parallel a dramatic improvement of similarity between biological replicates assayed in different plates. The proposed methodology is fully general and can be applied to any highly multiplexed assay performed in multiwell format. CONTACT: ac2248@columbia.edu SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.
Assuntos
Bioensaio , Técnicas Analíticas Microfluídicas/métodos , Transcriptoma , Algoritmos , Automação , Viés , Biblioteca Gênica , Humanos , Análise de Componente PrincipalRESUMO
While Brachypodium distachyon (Brachypodium) is an emerging model for grasses, no expression atlas or gene coexpression network is available. Such tools are of high importance to provide insights into the function of Brachypodium genes. We present a detailed Brachypodium expression atlas, capturing gene expression in its major organs at different developmental stages. The data were integrated into a large-scale coexpression database ( www.gene2function.de), enabling identification of duplicated pathways and conserved processes across 10 plant species, thus allowing genome-wide inference of gene function. We highlight the importance of the atlas and the platform through the identification of duplicated cell wall modules, and show that a lignin biosynthesis module is conserved across angiosperms. We identified and functionally characterised a putative ferulate 5-hydroxylase gene through overexpression of it in Brachypodium, which resulted in an increase in lignin syringyl units and reduced lignin content of mature stems, and led to improved saccharification of the stem biomass. Our Brachypodium expression atlas thus provides a powerful resource to reveal functionally related genes, which may advance our understanding of important biological processes in grasses.
Assuntos
Brachypodium/citologia , Brachypodium/genética , Parede Celular/genética , Regulação da Expressão Gênica de Plantas , Redes Reguladoras de Genes , Genes de Plantas , Lignina/metabolismo , Arabidopsis/genética , Bases de Dados Genéticas , Oryza/genética , Caules de Planta/metabolismo , Plantas Geneticamente Modificadas , Transcriptoma/genéticaRESUMO
The Group VII Ethylene Responsive Factors (ERFs-VII) RAP2.2 and RAP2.12 have been mainly characterized with regard to their contribution as activators of fermentation in plants. However, transcriptional changes measured in conditions that stabilize these transcription factors exceed the mere activation of this biochemical pathway, implying additional roles performed by the ERF-VIIs in other processes. We evaluated gene expression in transgenic Arabidopsis lines expressing a stabilized form of RAP2.12, or hampered in ERF-VII activity, and identified genes affected by this transcriptional regulator and its homologs, including some involved in oxidative stress response, which are not universally induced under anaerobic conditions. The contribution of the ERF-VIIs in regulating this set of genes in response to chemically induced or submergence-stimulated mitochondria malfunctioning was found to depend on the plant developmental stage. A similar age-dependent mechanism also restrained ERF-VII activity upon the core-hypoxic genes, independently of the N-end rule pathway, which is accounted for the control of the anaerobic response. To conclude, this study shed new light on a dual role of ERF-VII proteins under submergence: as positive regulators of the hypoxic response and as repressors of oxidative-stress related genes, depending on the developmental stage at which plants are challenged by stress conditions.