RESUMEN
With global climate changes and the increased demand for food due to expected world population growth, genetic improvement programs have aimed at producing crops with increased yield and tolerance to environmental stresses, such as drought, salinity, and pathogens. On the other hand, genetic improvement programs via biotechnology require candidate genes that confer traits of interest to be incorporated into improved crops. In this regard, genes encoding transcription factors (TFs) can be promising since they are proteins that transcriptionally regulate the expression of target genes related to the most diverse roles in the plant, including defense against stresses. Among TFs, bZIP (basic leucine zipper) proteins regulate many developmental and physiological processes in the plant, such as seed formation, fruit ripening, nutrient assimilation, and defense response to abiotic and biotic stresses. In this review, we aim to highlight the main advances in the potential use of bZIP TFs in the genetic improvement of crops. We address this potential mainly regarding crop tolerance to stresses and other agricultural traits, such as increased yield and fruit features.
Asunto(s)
Factores de Transcripción con Cremalleras de Leucina de Carácter Básico , Proteínas de Plantas , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Factores de Transcripción con Cremalleras de Leucina de Carácter Básico/genética , Factores de Transcripción con Cremalleras de Leucina de Carácter Básico/metabolismo , Productos Agrícolas/genética , Productos Agrícolas/metabolismo , Biotecnología , Estrés Fisiológico/genética , Regulación de la Expresión Génica de las PlantasRESUMEN
INTRODUCTION: BTB and CNC homology 1 (Bach1) is a protein that antagonizes some actions of nuclear factor erythroid 2-related factor-2 (Nrf2), the master regulator of cytoprotective responses. Bach1 binds to genomic DNA and inhibits the synthesis of antioxidant enzymes, thereby increasing inflammation. Bach1 may be a therapeutic target for mitigating inflammation in chronic kidney disease (CKD) patients. However, no clinical study has been reported on Bach1 in this population. This study aimed to evaluate Bach1 mRNA expression with different treatments for CKD, including conservative treatment (nondialysis), hemodialysis (HD), and peritoneal dialysis (PD). METHODS: Twenty patients undergoing HD (56.5 [19] years), 15 on PD (54 [24] years) and 13 nondialysis patients (63 [10] years, with an estimated glomerular filtration rate of 41 [14] mL/min/1.73 m2 ) were enrolled in the study. The mRNA expression of Nrf2, NF-kB, heme oxygenase 1 (HO-1), and Bach1 was evaluated in peripheral blood mononuclear cells using quantitative real-time polymerase chain reaction. Malondialdehyde (MDA) was evaluated as a lipid peroxidation marker. Routine biochemical parameters were also evaluated. FINDINGS: As expected, patients on dialysis were more inflamed. Bach1 mRNA expression was significantly higher in patients undergoing HD than in PD and nondialysis patients (p < 0.007). The mRNA expression of HO-1, NF-kB, and Nrf2 was not different in the groups. CONCLUSION: In conclusion, CKD patients on HD exhibited an upregulation of Bach1 mRNA expression compared to patients on PD treatment and nondialysis CKD patients. The association between Nrf2 and Bach1 expression in these patients warrants further investigation.
Asunto(s)
Factor 2 Relacionado con NF-E2 , Insuficiencia Renal Crónica , Humanos , Factor 2 Relacionado con NF-E2/genética , Factor 2 Relacionado con NF-E2/metabolismo , Factores de Transcripción con Cremalleras de Leucina de Carácter Básico/genética , Factores de Transcripción con Cremalleras de Leucina de Carácter Básico/metabolismo , FN-kappa B/metabolismo , Leucocitos Mononucleares/metabolismo , Diálisis Renal , Hemo-Oxigenasa 1/genética , Hemo-Oxigenasa 1/metabolismo , Insuficiencia Renal Crónica/genética , Insuficiencia Renal Crónica/terapia , Inflamación , ARN Mensajero/genética , ARN Mensajero/metabolismoRESUMEN
The circadian rhythm disorder and abnormal expression of rhythm genes are related to many diseases, especially cancer. Rhythm gene NFIL3 is involved in energy metabolism and immune cell differentiation, and its aberrant expression is associated with metabolic diseases and inflammation. Previously, numerous studies have shown that aberrant NFIL3 expression is associated with tumorigenesis, progression, and chemotherapy resistance. For instance, NFIL3 performs as a nuclear transcription factor, impacts cell proliferation, represses apoptosis, and promotes cancer cell invasion and metastasis by regulating the transcription of target genes. In addition, NFIL3 expressed in cancer cells influences the type and proportion of infiltrated immune cells in the tumor microenvironment. Increased expression of NFIL3 induces the chemotherapy and immunotherapy resistance in cancer. In this review, we summarized the pathological functions of NFIL3 in tumorigenesis, cancer development, and treatment. The rhythm gene NFIL3 can be used as a promising target in cancer therapy in the future.
Asunto(s)
Factores de Transcripción con Cremalleras de Leucina de Carácter Básico , Neoplasias , Humanos , Factores de Transcripción con Cremalleras de Leucina de Carácter Básico/genética , Factores de Transcripción con Cremalleras de Leucina de Carácter Básico/metabolismo , Regulación de la Expresión Génica , Factores de Transcripción/metabolismo , Ritmo Circadiano/genética , Neoplasias/genética , Carcinogénesis/genética , Microambiente Tumoral/genéticaRESUMEN
Salicylic acid (SA) is a hormone that modulates plant defenses by inducing changes in gene expression. The mechanisms that control SA accumulation are essential for understanding the defensive process. TGA transcription factors from clade II in Arabidopsis, which include the proteins TGA2, TGA5, and TGA6, are known to be key positive mediators for the transcription of genes such as PR-1 that are induced by SA application. However, unexpectedly, stress conditions that induce SA accumulation, such as infection with the avirulent pathogen P. syringae DC3000/AvrRPM1 and UV-C irradiation, result in enhanced PR-1 induction in plants lacking the clade II TGAs (tga256 plants). Increased PR-1 induction was accompanied by enhanced isochorismate synthase-dependent SA production as well as the upregulation of several genes involved in the hormone's accumulation. In response to avirulent P. syringae, PR-1 was previously shown to be controlled by both SA-dependent and -independent pathways. Therefore, the enhanced induction of PR-1 (and other defense genes) and accumulation of SA in the tga256 mutant plants is consistent with the clade II TGA factors providing negative feedback regulation of the SA-dependent and/or -independent pathways. Together, our results indicate that the TGA transcription factors from clade II negatively control SA accumulation under stress conditions that induce the hormone production. Our study describes a mechanism involving old actors playing new roles in regulating SA homeostasis under stress.
Asunto(s)
Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/genética , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Factores de Transcripción con Cremalleras de Leucina de Carácter Básico/genética , Regulación de la Expresión Génica de las Plantas , Hormonas/metabolismo , Mutación , Enfermedades de las Plantas/genética , Pseudomonas syringae , Ácido Salicílico/metabolismo , Factores de Transcripción/genética , Factores de Transcripción/metabolismoRESUMEN
Nitrate is a nutrient and a potent signal that impacts global gene expression in plants. However, the regulatory factors controlling temporal and cell type-specific nitrate responses remain largely unknown. We assayed nitrate-responsive transcriptome changes in five major root cell types of the Arabidopsis thaliana root as a function of time. We found that gene-expression response to nitrate is dynamic and highly localized and predicted cell type-specific transcription factor (TF)-target interactions. Among cell types, the endodermis stands out as having the largest and most connected nitrate-regulatory gene network. ABF2 and ABF3 are major hubs for transcriptional responses in the endodermis cell layer. We experimentally validated TF-target interactions for ABF2 and ABF3 by chromatin immunoprecipitation followed by sequencing and a cell-based system to detect TF regulation genome-wide. Validated targets of ABF2 and ABF3 account for more than 50% of the nitrate-responsive transcriptome in the endodermis. Moreover, ABF2 and ABF3 are involved in nitrate-induced lateral root growth. Our approach offers an unprecedented spatiotemporal resolution of the root response to nitrate and identifies important components of cell-specific gene regulatory networks.
Asunto(s)
Proteínas de Arabidopsis/genética , Factores de Transcripción con Cremalleras de Leucina de Carácter Básico/genética , Proteínas de Unión al ADN/genética , Regulación de la Expresión Génica de las Plantas , Nitratos/metabolismo , Fenómenos Fisiológicos de las Plantas , Factores de Transcripción/genética , Arabidopsis/fisiología , Proteínas de Arabidopsis/metabolismo , Factores de Transcripción con Cremalleras de Leucina de Carácter Básico/metabolismo , Biología Computacional/métodos , Proteínas de Unión al ADN/metabolismo , Perfilación de la Expresión Génica , Ontología de Genes , Redes Reguladoras de Genes , Modelos Biológicos , Especificidad de Órganos/genética , Raíces de Plantas/fisiología , Factores de Transcripción/metabolismo , TranscriptomaRESUMEN
Adjustment to energy starvation is crucial to ensure growth and survival. In Arabidopsis thaliana (Arabidopsis), this process relies in part on the phosphorylation of the circadian clock regulator bZIP63 by SUCROSE non-fermenting RELATED KINASE1 (SnRK1), a key mediator of responses to low energy. We investigated the effects of mutations in bZIP63 on plant carbon (C) metabolism and growth. Results from phenotypic, transcriptomic and metabolomic analysis of bZIP63 mutants prompted us to investigate the starch accumulation pattern and the expression of genes involved in starch degradation and in the circadian oscillator. bZIP63 mutation impairs growth under light-dark cycles, but not under constant light. The reduced growth likely results from the accentuated C depletion towards the end of the night, which is caused by the accelerated starch degradation of bZIP63 mutants. The diel expression pattern of bZIP63 is dictated by both the circadian clock and energy levels, which could determine the changes in the circadian expression of clock and starch metabolic genes observed in bZIP63 mutants. We conclude that bZIP63 composes a regulatory interface between the metabolic and circadian control of starch breakdown to optimize C usage and plant growth.
Asunto(s)
Proteínas de Arabidopsis , Arabidopsis , Relojes Circadianos , Arabidopsis/genética , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Factores de Transcripción con Cremalleras de Leucina de Carácter Básico/genética , Factores de Transcripción con Cremalleras de Leucina de Carácter Básico/metabolismo , Relojes Circadianos/genética , Ritmo Circadiano/genética , Regulación de la Expresión Génica de las Plantas , Fotoperiodo , Proteínas Serina-Treonina Quinasas/metabolismo , AzúcaresRESUMEN
The human T-cell lymphotropic virus type-1 (HTLV-1) is associated with severe pathologies, such as HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP), adult T-cell leukemia-lymphoma (ATLL), and infective dermatitis associated with the HTLV-1 (IDH). Interestingly, HTLV-1 infection does not necessarily imply the development of pathological processes and it is unknown why some patients remain asymptomatic carriers (AC). Despite some mutations in the HTLV-1 genome appear to influence the outcome of HTLV-1, there are few studies that characterize molecularly the hbz region. This study aimed to perform the molecular characterization of hbz gene isolated from patients with different clinical outcomes. A total of 15 sequences were generated and analyzed with 571 sequences previously published. The analises showed that the R119Q mutation seems to be related to HTLV-1 clinical conditions since the frequency of this HBZ mutation is significantly different in comparison between AC with HAM/TSP and ATLL. The R119Q mutation is possibly a protective factor as the frequency is higher in AC sequences.
Asunto(s)
Factores de Transcripción con Cremalleras de Leucina de Carácter Básico/genética , Variación Genética , Genoma Viral , Infecciones por HTLV-I/virología , Virus Linfotrópico T Tipo 1 Humano/genética , Mutación , Proteínas de los Retroviridae/genética , Adulto , Genómica , Infecciones por HTLV-I/sangre , Infecciones por HTLV-I/clasificación , Humanos , Leucocitos Mononucleares/virología , Paraparesia Espástica Tropical/virología , Carga ViralRESUMEN
Plants are sessile organisms, which are vulnerable to environmental stresses. As such, plants have developed multiple molecular, physiological, and cellular mechanisms to cope with natural stressors. However, these environmental adversities, including drought, are sources of the main agribusiness problems since they interfere with plant growth and productivity. Particularly under water deprivation conditions, the abscisic acid-responsive element-binding protein AREB1/ABF2 plays an important role in drought stress response and physiological adaptation. In this investigation, we provide substantial confirmation for the role of AREB1/ABF2 in plant survival under severe water deficit using the CRISPR activation (CRISPRa) technique to enhance the AREB1 gene expression. In our strategy, the inactive nuclease dCas9 was fused with an Arabidopsis histone acetyltransferase 1, which improves gene expression by remodeling chromatin. The AREB1 overexpression promotes an improvement in the physiological performance of the transgenic homozygous plants under drought, which was associated with an increase in chlorophyll content, antioxidant enzyme activity, and soluble sugar accumulation, leading to lower reactive oxygen species accumulation. Finally, we found that the CRISPR-mediated up-regulation of AREB1 changes the abundance of several downstream ABA-inducible genes, allowing us to report that CRISPRa dCas9-HAT is a valuable biotechnological tool to improve drought stress tolerance through the positive regulation of AREB1.
Asunto(s)
Proteínas de Arabidopsis/fisiología , Factores de Transcripción con Cremalleras de Leucina de Carácter Básico/fisiología , Fenómenos Fisiológicos de las Plantas/genética , Arabidopsis/genética , Arabidopsis/fisiología , Proteínas de Arabidopsis/genética , Factores de Transcripción con Cremalleras de Leucina de Carácter Básico/genética , Proteína 9 Asociada a CRISPR , Sistemas CRISPR-Cas , Deshidratación/genética , Edición Génica , Regulación de la Expresión Génica de las Plantas , Plantas Modificadas GenéticamenteRESUMEN
Translational control targeting the initiation phase is central to the regulation of gene expression. Understanding all of its aspects requires substantial technological advancements. Here we modified yeast translation complex profile sequencing (TCP-seq), related to ribosome profiling, and adapted it for mammalian cells. Human TCP-seq, capable of capturing footprints of 40S subunits (40Ss) in addition to 80S ribosomes (80Ss), revealed that mammalian and yeast 40Ss distribute similarly across 5'TRs, indicating considerable evolutionary conservation. We further developed yeast and human selective TCP-seq (Sel-TCP-seq), enabling selection of 40Ss and 80Ss associated with immuno-targeted factors. Sel-TCP-seq demonstrated that eIF2 and eIF3 travel along 5' UTRs with scanning 40Ss to successively dissociate upon AUG recognition; notably, a proportion of eIF3 lingers on during the initial elongation cycles. Highlighting Sel-TCP-seq versatility, we also identified four initiating 48S conformational intermediates, provided novel insights into ATF4 and GCN4 mRNA translational control, and demonstrated co-translational assembly of initiation factor complexes.
Asunto(s)
Complejos Multiproteicos/metabolismo , Factores de Iniciación de Péptidos/metabolismo , Biosíntesis de Proteínas , Ribosomas/metabolismo , Regiones no Traducidas 5' , Factor de Transcripción Activador 4/genética , Factor de Transcripción Activador 4/metabolismo , Factores de Transcripción con Cremalleras de Leucina de Carácter Básico/genética , Factores de Transcripción con Cremalleras de Leucina de Carácter Básico/metabolismo , Codón Iniciador , Factor 2 Eucariótico de Iniciación/genética , Factor 2 Eucariótico de Iniciación/metabolismo , Factor 3 de Iniciación Eucariótica/genética , Factor 3 de Iniciación Eucariótica/metabolismo , Células HEK293 , Humanos , Complejos Multiproteicos/genética , Factores de Iniciación de Péptidos/genética , Subunidades Ribosómicas Pequeñas de Eucariotas/genética , Subunidades Ribosómicas Pequeñas de Eucariotas/metabolismo , Ribosomas/genética , Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismoRESUMEN
Objective Type 1 diabetes mellitus (T1DM) is an autoimmune disorder caused by a complex interaction between environmental and genetic risk factors. BTB domain and CNC homolog 2 (BACH2) gene encodes a transcription factor that acts on the differentiation and formation of B and T lymphocytes. BACH2 is also involved in the suppression of apoptosis and inflammation in pancreatic beta-cells, indicating a role for it in the development of T1DM. Therefore, the aim of this study was to evaluate the association of the BACH2 rs11755527 single nucleotide polymorphism (SNP) with T1DM. Subjects and methods This case-control study comprised 475 patients with T1DM and 598 nondiabetic individuals. The BACH2 rs11755527 (C/G) SNP was genotyped using real-time PCR with TaqMan MGB probes. Results Genotype distributions of rs11755527 SNP were in accordance with frequencies predicted by the Hardy-Weinberg equilibrium in case and control groups and were similar between groups (P = 0.729). The minor allele frequency was 43.6% in cases and 42.5% in controls (P = 0.604). Moreover, the G allele frequency did not differ between groups when considering different inheritance models and adjusting for age, gender, body mass index, and HLA DR/DQ genotypes of high-risk for T1DM. Although, well-known high-risk T1DM HLA DR/DQ genotypes were associated with T1DM in our population [OR= 7.42 (95% CI 3.34 - 17.0)], this association was not influenced by the rs11755527 SNP. Conclusion The BACH2 rs11755527 SNP seems not to be associated with T1DM in a Brazilian population.
Asunto(s)
Factores de Transcripción con Cremalleras de Leucina de Carácter Básico/genética , Diabetes Mellitus Tipo 1/genética , Predisposición Genética a la Enfermedad , Polimorfismo de Nucleótido Simple/genética , Adulto , Brasil , Estudios de Casos y Controles , Femenino , Frecuencia de los Genes , Genotipo , Humanos , Masculino , Persona de Mediana Edad , Reacción en Cadena de la Polimerasa , Factores de RiesgoRESUMEN
ABSTRACT Objective Type 1 diabetes mellitus (T1DM) is an autoimmune disorder caused by a complex interaction between environmental and genetic risk factors. BTB domain and CNC homolog 2 (BACH2) gene encodes a transcription factor that acts on the differentiation and formation of B and T lymphocytes. BACH2 is also involved in the suppression of apoptosis and inflammation in pancreatic beta-cells, indicating a role for it in the development of T1DM. Therefore, the aim of this study was to evaluate the association of the BACH2 rs11755527 single nucleotide polymorphism (SNP) with T1DM. Subjects and methods This case-control study comprised 475 patients with T1DM and 598 nondiabetic individuals. The BACH2 rs11755527 (C/G) SNP was genotyped using real-time PCR with TaqMan MGB probes. Results Genotype distributions of rs11755527 SNP were in accordance with frequencies predicted by the Hardy-Weinberg equilibrium in case and control groups and were similar between groups (P = 0.729). The minor allele frequency was 43.6% in cases and 42.5% in controls (P = 0.604). Moreover, the G allele frequency did not differ between groups when considering different inheritance models and adjusting for age, gender, body mass index, and HLA DR/DQ genotypes of high-risk for T1DM. Although, well-known high-risk T1DM HLA DR/DQ genotypes were associated with T1DM in our population [OR= 7.42 (95% CI 3.34 - 17.0)], this association was not influenced by the rs11755527 SNP. Conclusion The BACH2 rs11755527 SNP seems not to be associated with T1DM in a Brazilian population.
Asunto(s)
Humanos , Masculino , Femenino , Adulto , Predisposición Genética a la Enfermedad , Polimorfismo de Nucleótido Simple/genética , Diabetes Mellitus Tipo 1/genética , Factores de Transcripción con Cremalleras de Leucina de Carácter Básico/genética , Brasil , Estudios de Casos y Controles , Reacción en Cadena de la Polimerasa , Factores de Riesgo , Frecuencia de los Genes , Genotipo , Persona de Mediana EdadRESUMEN
Seeds germinating underground display a specific developmental programme, termed skotomorphogenesis, to ensure survival of the emerging seedlings until they reach the light. They rapidly elongate the hypocotyl and maintain the cotyledons closed, forming a hook with the hypocotyl in order to protect apical meristematic cells from mechanical damage. Such crucial events for the fate of the seedling are tightly regulated and although some transcriptional regulators and phytohormones are known to be implicated in this regulation, we are still far from a complete understanding of these biological processes. Our work provides information on the diverse roles in skotomorphogenesis of the core components of microRNA biogenesis in Arabidopsis, HYL1, DCL1, and SE. We show that hypocotyl elongation is promoted by all these components, probably through the action of specific miRNAs. Hook development also depends on these proteins however, remarkably, HYL1 exerts its role in an opposite way to DCL1 and SE. Interestingly, we found that a specific HYL1 domain involved in protein-protein interaction is required for this function. Genetic evidences also point to the phosphorylation status of HYL1 as important for this function. We propose that HYL1 help maintain the hook closed during early skotomorphogenesis in a microprocessor-independent manner by repressing the activity of HY5, the transcriptional master regulator that triggers light responses. This work uncovers a previously unnoticed link between components of the miRNA biogenesis machinery, the skotomorphogenic growth, and hook development in Arabidopsis.
Asunto(s)
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Factores de Transcripción con Cremalleras de Leucina de Carácter Básico/metabolismo , Proteínas de Unión al ARN/metabolismo , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Factores de Transcripción con Cremalleras de Leucina de Carácter Básico/genética , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Regulación de la Expresión Génica de las Plantas/genética , Regulación de la Expresión Génica de las Plantas/fisiología , MicroARNs/genética , MicroARNs/metabolismo , Proteínas de Unión al ARN/genética , Ribonucleasa III/genética , Ribonucleasa III/metabolismoRESUMEN
In the presence of galactose, lithium ions activate the unfolded protein response (UPR) by inhibiting phosphoglucomutase activity and causing the accumulation of galactose-related metabolites, including galactose-1-phosphate. These metabolites also accumulate in humans who have the disease classic galactosemia. Here, we demonstrate that Saccharomyces cerevisiae yeast strains harboring a deletion of UBX4, a gene encoding a partner of Cdc48p in the endoplasmic reticulum-associated degradation (ERAD) pathway, exhibit delayed UPR activation after lithium and galactose exposure because the deletion decreases galactose-1-phosphate levels. The delay in UPR activation did not occur in yeast strains in which key ERAD or proteasomal pathway genes had been disrupted, indicating that the ubx4Δ phenotype is ERAD-independent. We also observed that the ubx4Δ strain displays decreased oxygen consumption. The inhibition of mitochondrial respiration was sufficient to diminish galactose-1-phosphate levels and, consequently, affects UPR activation. Finally, we show that the deletion of the AMP-activated protein kinase ortholog-encoding gene SNF1 can restore the oxygen consumption rate in ubx4Δ strain, thereby reestablishing galactose metabolism, UPR activation, and cellular adaption to lithium-galactose challenge. Our results indicate a role for Ubx4p in yeast mitochondrial function and highlight that mitochondrial and endoplasmic reticulum functions are intertwined through galactose metabolism. These findings also shed new light on the mechanisms of lithium action and on the pathophysiology of galactosemia.
Asunto(s)
Galactosa/farmacología , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Litio/farmacología , Mitocondrias/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/metabolismo , Respuesta de Proteína Desplegada/efectos de los fármacos , Factores de Transcripción con Cremalleras de Leucina de Carácter Básico/genética , Factores de Transcripción con Cremalleras de Leucina de Carácter Básico/metabolismo , Retículo Endoplásmico/metabolismo , Galactosa/metabolismo , Galactosafosfatos/metabolismo , Péptidos y Proteínas de Señalización Intracelular/deficiencia , Péptidos y Proteínas de Señalización Intracelular/genética , Consumo de Oxígeno , Proteínas Serina-Treonina Quinasas/deficiencia , Proteínas Serina-Treonina Quinasas/genética , Empalme del ARN , Proteínas Represoras/genética , Proteínas Represoras/metabolismo , Proteínas de Saccharomyces cerevisiae/genéticaRESUMEN
Drought episodes decrease plant growth and productivity, which in turn cause high economic losses. Plants naturally sense and respond to water stress by activating specific signalling pathways leading to physiological and developmental adaptations. Genetically engineering genes that belong to these pathways might improve the drought tolerance of plants. The abscisic acid (ABA)-responsive element binding protein 1/ABRE binding factor (AREB1/ABF2) is a key positive regulator of the drought stress response. We investigated whether the CRISPR activation (CRISPRa) system that targets AREB1 might contribute to improve drought stress tolerance in Arabidopsis. Arabidopsis histone acetyltransferase 1 (AtHAT1) promotes gene expression activation by switching chromatin to a relaxed state. Stable transgenic plants expressing chimeric dCas9HAT were first generated. Then, we showed that the CRISPRa dCas9HAT mechanism increased the promoter activity controlling the ß-glucuronidase (GUS) reporter gene. To activate the endogenous promoter of AREB1, the CRISPRa dCas9HAT system was set up, and resultant plants showed a dwarf phenotype. Our qRT-PCR experiments indicated that both AREB1 and RD29A, a gene positively regulated by AREB1, exhibited higher gene expression than the control plants. The plants generated here showed higher chlorophyll content and faster stomatal aperture under water deficit, in addition to a better survival rate after drought stress. Altogether, we report that CRISPRa dCas9HAT is a valuable biotechnological tool to improve drought stress tolerance through the positive regulation of AREB1.
Asunto(s)
Aclimatación/genética , Proteínas de Arabidopsis/genética , Arabidopsis/fisiología , Factores de Transcripción con Cremalleras de Leucina de Carácter Básico/genética , Proteína 9 Asociada a CRISPR/genética , Plantas Modificadas Genéticamente/fisiología , Factores de Transcripción/genética , Proteínas de Arabidopsis/metabolismo , Sistemas CRISPR-Cas/genética , Sequías , Regulación de la Expresión Génica de las Plantas/fisiología , Histona Acetiltransferasas , Regiones Promotoras Genéticas/genética , Proteínas Recombinantes de Fusión/genética , Factores de Transcripción/metabolismoRESUMEN
Plants must defend themselves against pathogens. The defense response requires greater protein synthesis, which generates endoplasmic reticulum (ER) stress, yet failure to attenuate this stress has detrimental effects. WRKY7/11/17 transcription factors (TFs) are negative regulators of immunity since mutants are more resistant to Pseudomonas syringae pv tomato (Pst) infection. Here, we reveal a connection between ER-stress and the molecular mechanisms underlying the wrky mutant phenotype. The bZIP28 TF upregulates ER-chaperone expression (BiP1/2, ERdj3B, and SDF2) upon exposure of Arabidopsis to a bacterial defense elicitor, flagellin 22 (Flg22). Also, the activation of ER-chaperones is more sustained in double and triple wrky mutants treated with Flg22, suggesting that WRKY7/11/17 TFs downregulate these genes. Moreover, wrky mutants accumulate more bZIP28 transcripts in response to Flg22, indicating that WRKY7/11/17 transcriptionally repress this TF. Using Arabidopsis protoplasts, we also demonstrate that WRKYs bind to the bZIP28 promoter via W-box elements. Additionally, triple wrky mutants are more resistant, whilst bzip28 mutants are more susceptible, to Pst infection. Finally, we postulate a model of PAMP-Triggered Immunity regulation, where Flg22 activates bZIP28-signaling inducing the expression of ER-stress genes, as well as WRKY7/11/17 expression, which in turn inhibits PTI by downregulating bZIP28, controlling physiological responses in the Arabidopsis-Pst interaction.
Asunto(s)
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Arabidopsis/microbiología , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Factores de Transcripción con Cremalleras de Leucina de Carácter Básico/genética , Factores de Transcripción con Cremalleras de Leucina de Carácter Básico/metabolismo , Regulación de la Expresión Génica de las Plantas , Inmunidad de la Planta/genética , Inmunidad de la Planta/fisiología , Plantas Modificadas Genéticamente/genética , Plantas Modificadas Genéticamente/metabolismo , Plantas Modificadas Genéticamente/microbiología , Pseudomonas syringae/patogenicidad , Factores de Transcripción/genética , Factores de Transcripción/metabolismo , Respuesta de Proteína Desplegada/genética , Respuesta de Proteína Desplegada/fisiologíaRESUMEN
Human T-cell leukemia virus type 1 (HTLV-1) is the etiological agent of adult T-cell leukemia (ATL). The HTLV-1 basic leucine zipper protein (HBZ) is expressed in all cases of ATL and is directly associated with virus pathogenicity. The two isoforms of the HBZ protein are synthesized from antisense messenger RNAs (mRNAs) that are either spliced (sHBZ) or unspliced (usHBZ) versions of the HBZ transcript. The sHBZ and usHBZ mRNAs have entirely different 5'untranslated regions (5'UTR) and are differentially expressed in cells, with the sHBZ protein being more abundant. Here, we show that differential expression of the HBZ isoforms is regulated at the translational level. Translation initiation of the usHBZ mRNA relies on a cap-dependent mechanism, while the sHBZ mRNA uses internal initiation. Based on the structural data for the sHBZ 5'UTR generated by SHAPE in combination with 5' and 3' deletion mutants, the minimal region harboring IRES activity was mapped to the 5'end of the sHBZ mRNA. In addition, the sHBZ IRES recruited the 40S ribosomal subunit upstream of the initiation codon, and IRES activity was found to be dependent on the ribosomal protein eS25 and eIF5A.
Asunto(s)
Factores de Transcripción con Cremalleras de Leucina de Carácter Básico/genética , Virus Linfotrópico T Tipo 1 Humano/genética , Iniciación de la Cadena Peptídica Traduccional , ARN Mensajero/genética , ARN Viral/genética , Proteínas de los Retroviridae/genética , Regiones no Traducidas 5'/genética , Animales , Factores de Transcripción con Cremalleras de Leucina de Carácter Básico/metabolismo , Células COS , Chlorocebus aethiops , Regulación Viral de la Expresión Génica , Células HEK293 , Células HeLa , Virus Linfotrópico T Tipo 1 Humano/metabolismo , Humanos , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Empalme del ARN , ARN Mensajero/metabolismo , ARN Viral/metabolismo , Proteínas de los Retroviridae/metabolismoRESUMEN
KEY MESSAGE: In this study we show that expression of the Arabidopsis ABF4 gene in potato increases tuber yield under normal and abiotic stress conditions, improves storage capability and processing quality of the tubers, and enhances salt and drought tolerance. Potato is the third most important food crop in the world. Potato plants are susceptible to salinity and drought, which negatively affect crop yield, tuber quality and market value. The development of new varieties with higher yields and increased tolerance to adverse environmental conditions is a main objective in potato breeding. In addition, tubers suffer from undesirable sprouting during storage that leads to major quality losses; therefore, the control of tuber sprouting is of considerable economic importance. ABF (ABRE-binding factor) proteins are bZIP transcription factors that regulate abscisic acid signaling during abiotic stress. ABF proteins also play an important role in the tuberization induction. We developed transgenic potato plants constitutively expressing the Arabidopsis ABF4 gene (35S::ABF4). In this study, we evaluated the performance of 35S::ABF4 plants grown in soil, determining different parameters related to tuber yield, tuber quality (carbohydrates content and sprouting behavior) and tolerance to salt and drought stress. Besides enhancing salt stress and drought tolerance, constitutive expression of ABF4 increases tuber yield under normal and stress conditions, enhances storage capability and improves the processing quality of the tubers.
Asunto(s)
Proteínas de Arabidopsis/genética , Arabidopsis/genética , Factores de Transcripción con Cremalleras de Leucina de Carácter Básico/genética , Sequías , Regulación de la Expresión Génica de las Plantas , Tubérculos de la Planta/genética , Tubérculos de la Planta/fisiología , Tolerancia a la Sal/genética , Solanum tuberosum/genética , Proteínas de Arabidopsis/metabolismo , Factores de Transcripción con Cremalleras de Leucina de Carácter Básico/metabolismo , Clorofila/metabolismo , Transporte de Electrón/efectos de los fármacos , Regulación de la Expresión Génica de las Plantas/efectos de los fármacos , Oxidación-Reducción , Fotosíntesis/efectos de los fármacos , Estomas de Plantas/efectos de los fármacos , Estomas de Plantas/genética , Estomas de Plantas/fisiología , Transpiración de Plantas/efectos de los fármacos , Transpiración de Plantas/genética , Tubérculos de la Planta/efectos de los fármacos , Plantas Modificadas Genéticamente , Prolina/metabolismo , Tolerancia a la Sal/efectos de los fármacos , Cloruro de Sodio/farmacología , Solanum tuberosum/efectos de los fármacos , AguaRESUMEN
In transplantation, donor dendritic cells (do-DCs) initiate the alloimmune response either by direct interaction with host T cells or by transferring intact donor MHC to host DCs. However, how do-DCs can be targeted for improving allograft survival is still unclear. Here we show CD103+ DCs are the major do-DC subset involved in the acute rejection of murine skin transplants. In the absence of CD103+ do-DCs, less donor MHC-II is carried to host lymph nodes, fewer allogenic T cells are primed and allograft survival is prolonged. Incubation of skin grafts with the anti-inflammatory mycobacterial protein DnaK reduces donor MHC-II on CD103+DCs and prolongs graft survival. This effect is mediated through IL-10-induced March1, which ubiquitinates and decreases MHC-II levels. Importantly, in vitro pre-treatment of human DCs with DnaK reduces their ability to prime alloreactive T cells. Our findings demonstrate a novel therapeutic approach to dampen alloimmunity by targeting donor MHC-II on CD103+DCs.
Asunto(s)
Antígenos CD/metabolismo , Células Dendríticas/metabolismo , Cadenas alfa de Integrinas/metabolismo , Ubiquitina-Proteína Ligasas/metabolismo , Animales , Antígenos CD/genética , Factores de Transcripción con Cremalleras de Leucina de Carácter Básico/genética , Factores de Transcripción con Cremalleras de Leucina de Carácter Básico/metabolismo , Antígenos de Histocompatibilidad Clase II/genética , Antígenos de Histocompatibilidad Clase II/metabolismo , Cadenas alfa de Integrinas/genética , Interleucina-10/genética , Interleucina-10/metabolismo , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Proteínas Represoras/genética , Proteínas Represoras/metabolismo , Factor de Transcripción STAT3/genética , Factor de Transcripción STAT3/metabolismo , Ubiquitina-Proteína Ligasas/genéticaRESUMEN
Low temperatures, salinity, and drought cause significant crop losses. These conditions involve osmotic stress, triggering transcriptional remodeling, and consequently, the restitution of cellular homeostasis and growth recovery. Protein transcription factors regulate target genes, thereby mediating plant responses to stress. bZIP17 is a transcription factor involved in cellular responses to salinity and the unfolded protein response. Because salinity can also produce osmotic stress, the role of bZIP17 in response to osmotic stress was assessed. Mannitol treatments induced the transcript accumulation and protein processing of bZIP17. Transcriptomic analyses showed that several genes associated with seed storage and germination showed lower expression in bzip17 mutants than in wild-type plants. Interestingly, bZIP17 transcript was more abundant in seeds, and germination analyses revealed that wild-type plants germinated later than bzip17 mutants in the presence of mannitol, but no effects were observed when the seeds were exposed to ABA. Finally, the transcript levels of bZIP17 target genes that control seed storage and germination were assessed in seeds exposed to mannitol treatments, which showed lower expression levels in bzip17 mutants compared to the wild-type seeds. These results suggest that bZIP17 plays a role in osmotic stress, acting as a negative regulator of germination through the regulation of genes involved in seed storage and germination.
Asunto(s)
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Factores de Transcripción con Cremalleras de Leucina de Carácter Básico/metabolismo , Regulación de la Expresión Génica de las Plantas/fisiología , Germinación/fisiología , Presión Osmótica/fisiología , Semillas/metabolismo , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Factores de Transcripción con Cremalleras de Leucina de Carácter Básico/genética , Semillas/genéticaRESUMEN
Sunflecks, transient patches of light that penetrate through gaps in the canopy and transiently interrupt shade, are eco-physiologically and agriculturally important sources of energy for carbon gain, but our molecular understanding of how plant organs perceive and respond to sunflecks through photoreceptors remains limited. The UV-B photoreceptor UV RESISTANCE LOCUS8 (UVR8) is a recent addition to the list of plant photosensory receptors, and we have made considerable advances in our understanding of the physiology and molecular mechanisms of action of UVR8 and its signaling pathway. However, the function of UVR8 in the natural environment is poorly understood. Here, we show that the UVR8 dimer/monomer ratio responds quantitatively and reversibly to the intensity of sunflecks that interrupt shade in the field. Sunflecks reduced hypocotyl growth and increased CHALCONE SYNTHASE (CHS) and ELONGATED HYPOCOTYL5 gene expression and CHS protein abundance in wild-type Arabidopsis (Arabidopsis thaliana) seedlings, but the uvr8 mutant was impaired in these responses. UVR8 was also required for normal nuclear dynamics of CONSTITUTIVELY PHOTOMORPHOGENIC1. We propose that UVR8 plays an important role in the plant perception of and response to sunflecks.