RESUMO
Common beans (Phaseolus vulgaris L.), besides being an important source of nutrients such as iron, magnesium, and protein, are crucial for food security, especially in developing countries. Common bean cultivation areas commonly face production challenges due to drought occurrences, mainly during the reproductive period. Dry spells last approximately 20 days, enough time to compromise production. Hence, it is crucial to understand the genetic and molecular mechanisms that confer drought tolerance to improve common bean cultivars' adaptation to drought. Sixty six RNASeq libraries, generated from tolerant and sensitive cultivars in drought time sourced from the R5 phenological stage at 0 to 20 days of water deficit were sequenced, generated over 1.5 billion reads, that aligned to 62,524 transcripts originating from a reference transcriptome, as well as 6673 transcripts obtained via de novo assembly. Differentially expressed transcripts were functionally annotated, revealing a variety of genes associated with molecular functions such as oxidoreductase and transferase activity, as well as biological processes related to stress response and signaling. The presence of regulatory genes involved in signaling cascades and transcriptional control was also highlighted, for example, LEA proteins and dehydrins associated with dehydration protection, and transcription factors such as WRKY, MYB, and NAC, which modulate plant response to water deficit. Additionally, genes related to membrane and protein protection, as well as water and ion uptake and transport, were identified, including aquaporins, RING-type E3 ubiquitin transferases, antioxidant enzymes such as GSTs and CYPs, and thioredoxins. This study highlights the complexity of plant response to water scarcity, focusing on the functional diversity of the genes involved and their participation in the biological processes essential for plant adaptation to water stress. The identification of regulatory and cell protection genes offers promising prospects for genetic improvement aiming at the production of common bean varieties more resistant to drought. These findings have the potential to drive sustainable agriculture, providing valuable insights to ensure food security in a context of climate change.
Assuntos
Secas , Regulação da Expressão Gênica de Plantas , Phaseolus , Proteínas de Plantas , Phaseolus/genética , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Transcriptoma/genética , Estresse Fisiológico/genética , Adaptação Fisiológica/genética , Desidratação/genética , Perfilação da Expressão Gênica/métodos , Resistência à SecaRESUMO
Dehydration is a stress factor for organisms inhabiting natural habitats where water is scarce. Thus, it may be expected that species facing arid environments will develop mechanisms that maximize resistance to desiccation. Insects are excellent models for studying the effects of dehydration as well as the mechanisms and processes that prevent water loss since the effect of desiccation is greater due to the higher area/volume ratio than larger animals. Even though physiological and behavioral mechanisms to cope with desiccation are being understood, the genetic basis underlying the mechanisms related to variation in desiccation resistance and the context-dependent effect remain unsolved. Here we analyze the genetic bases of desiccation resistance in Drosophila melanogaster and identify candidate genes that underlie trait variation. Our quantitative genetic analysis of desiccation resistance revealed sexual dimorphism and extensive genetic variation. The phenotype-genotype association analyses (GWAS) identified 71 candidate genes responsible for total phenotypic variation in desiccation resistance. Half of these candidate genes were sex-specific suggesting that the genetic architecture underlying this adaptive trait differs between males and females. Moreover, the public availability of desiccation data analyzed on the same lines but in a different lab allows us to investigate the reliability and repeatability of results obtained in independent screens. Our survey indicates a pervasive micro-environment lab-dependent effect since we did not detect overlap in the sets of genes affecting desiccation resistance identified between labs.
Assuntos
Desidratação , Drosophila melanogaster , Animais , Feminino , Masculino , Drosophila melanogaster/genética , Desidratação/genética , Dessecação , Reprodutibilidade dos Testes , Drosophila/fisiologia , ÁguaRESUMO
Aging is a complex biological process, resulting in gradual and progressive decline in structure and function in many organ systems. Our objective is to determine if structural changes produced by aging vary with sex in a stressful situation such as dehydration. The expression of Slc12a3 mRNA in the renal cortex, α-smooth muscle actin (α-SMA), and fibronectin was evaluated in male and female rats, aged 3 and 18 months, submitted and not submitted to water deprivation (WD) for 48 h, respectively. When comparing ages, 18-month-old males showed a lower expression of Slc12a3 mRNA than 3-month-old males, and control and WD 18-month-old male and female rats exhibited a higher expression of α-SMA than the respective 3-month-old rats. Fibronectin was higher in both control and WD 18-month-old males than the respective 3-month-old males. In females, only the control 18-month-old rats showed higher fibronectin than the control 3-month-old rats. When we compared sex, control and WD 3-month-old female rats had a lower expression of Slc12a3 mRNA than the respective males. The WD 18-month-old male rats presented a higher expression of fibronectin and α-SMA than the WD 18-month-old female rats. When we compared hydric conditions, the WD 18-month-old males displayed a lower relative expression of Slc12a3 mRNA and higher α-SMA expression than the control 18-month-old males. Aging, sex, and dehydration lead to alterations in kidney structure.
Assuntos
Desidratação , Fibronectinas , Rim , Animais , Feminino , Masculino , Ratos , Envelhecimento/genética , Desidratação/genética , Fibronectinas/genética , Rim/patologia , RNA Mensageiro/genética , Privação de ÁguaRESUMO
Drought is one of the major factors limiting global crop yield. In Mexico, agriculture is expected to be severely affected by drought. The Capsicum genus has several crop species of agricultural importance. In this work, we analysed the Capsicum chinense plant physiological responses and differentially expressed genes under water stress mainly focused on the responses elicited following recovery through repetitive stress. Plants were cultivated in an experimental block. Each block consisted of plants under water deficit and a control group without deficit. Morphometric and functional parameters, and the expression of genes related to resistance to abiotic stresses were measured. Morphological differences were observed. Plants subjected to water deficit showed impaired growth. Nonetheless, in the physiological parameters, no differences were observed between treatments. We selected abiotic stress-related genes that include heat-shock proteins (HSPs), heat-shock factors (HSFs), transcription factors related to abiotic stress (MYB, ETR1 , and WRKY ), and those associated with biotic and abiotic stress responses (Jar1 and Lox2 ). HSF, HSP, MYB72, ETR1, Jar1, WRKYa , and Lox2 genes were involved in the response to water-deficit stress in C. chinense plants. In conclusion, our work may improve our understanding of the morphological, physiological, and molecular mechanisms underlying hydric stress response in C. chinense .
Assuntos
Capsicum , Aclimatação , Agricultura , Capsicum/genética , Desidratação/genética , Regulação da Expressão Gênica de PlantasRESUMO
Drought is a pivotal cause for crop yield reductions. When subjected to recurrent external stimuli, plants can develop memory of stress responses that, eventually, enables improved plant tolerance to environmental changes. In addition, despite causal relationships, these responses may vary according to hierarchical levels of observation. Thus, this study aims to check the responses of recurrent and non-recurrent stresses in two rice genotypes observing their drought memory responses at different levels of organization, that is, on a physiological, biochemical and metabolomic scale and for end in global PCA. For this, seventy variables were measured on the scales described in order to obtain a large number of observations. The memory responses were evident in almost all scales observed. The lowland genotype, especially plants not subjected to recurrent water shortage, showed higher damage to the photosynthetic apparatus under drought conditions, although it has exhibited more evident memory response effect after rehydration. On the other hand, the upland genotype appears to be more tolerant to drought insofar lower biochemical damage was observed. Specific behaviors of each genotype at biochemical and metabolomics levels and similar behavior at physiological level were observed. This study demonstrates the importance of observation at different hierarchical levels.
Assuntos
Adaptação Fisiológica/genética , Desidratação/genética , Desidratação/fisiopatologia , Secas , Oryza/genética , Oryza/fisiologia , Água/metabolismo , Brasil , Produtos Agrícolas/genética , Produtos Agrícolas/fisiologia , Regulação da Expressão Gênica de Plantas , Genes de Plantas , Variação Genética , Genótipo , Estresse Fisiológico/genéticaRESUMO
BACKGROUND: Desiccation tolerant Selaginella species evolved to survive extreme environmental conditions. Studies to determine the mechanisms involved in the acquisition of desiccation tolerance (DT) have focused on only a few Selaginella species. Due to the large diversity in morphology and the wide range of responses to desiccation within the genus, the understanding of the molecular basis of DT in Selaginella species is still limited. RESULTS: Here we present a reference transcriptome for the desiccation tolerant species S. sellowii and the desiccation sensitive species S. denticulata. The analysis also included transcriptome data for the well-studied S. lepidophylla (desiccation tolerant), in order to identify DT mechanisms that are independent of morphological adaptations. We used a comparative approach to discriminate between DT responses and the common water loss response in Selaginella species. Predicted proteomes show strong homology, but most of the desiccation responsive genes differ between species. Despite such differences, functional analysis revealed that tolerant species with different morphologies employ similar mechanisms to survive desiccation. Significant functions involved in DT and shared by both tolerant species included induction of antioxidant systems, amino acid and secondary metabolism, whereas species-specific responses included cell wall modification and carbohydrate metabolism. CONCLUSIONS: Reference transcriptomes generated in this work represent a valuable resource to study Selaginella biology and plant evolution in relation to DT. Our results provide evidence of convergent evolution of S. sellowii and S. lepidophylla due to the different gene sets that underwent selection to acquire DT.
Assuntos
Adaptação Fisiológica/genética , Desidratação/genética , Desidratação/fisiopatologia , Selaginellaceae/genética , Selaginellaceae/fisiologia , Especificidade da Espécie , Estresse Fisiológico/genética , Evolução Biológica , Perfilação da Expressão Gênica , Variação GenéticaRESUMO
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.
Assuntos
Proteínas de Arabidopsis/fisiologia , Fatores de Transcrição de Zíper de Leucina Básica/fisiologia , Fenômenos Fisiológicos Vegetais/genética , Arabidopsis/genética , Arabidopsis/fisiologia , Proteínas de Arabidopsis/genética , Fatores de Transcrição de Zíper de Leucina Básica/genética , Proteína 9 Associada à CRISPR , Sistemas CRISPR-Cas , Desidratação/genética , Edição de Genes , Regulação da Expressão Gênica de Plantas , Plantas Geneticamente ModificadasRESUMO
Peanut wild relatives (Arachis spp.) have high genetic diversity and are important sources of resistance to biotic and abiotic stresses. In this study, proteins were analyzed in root tissues of A. duranensis submitted to a progressive water deficit in soil and the differential abundance was compared to transcript expression profiles obtained by RNA-seq and qRT-PCR. Using a 2-DE approach, a total of 31 proteins were identified, most of which were associated with stress response and drought perception. These comprised a chitinase-2 (unique to stressed condition), an MLP-like protein, a glycine-rich protein DOT1-like, a maturase K and heat shock-related proteins (HSP70 - an isoform unique to the control, and HSP17.3). Other proteins unique to the control condition comprised a transcription initiation factor IIF subunit alpha-like protein, a SRPBCC ligand-binding domain superfamily protein, an Adenine phosphoribosyl transferase, a Leo1-like protein, a Cobalamine-independent methionine synthase and a Transmembrane emp24 domain-containing protein p24delta9-like. Correlation of mRNA expression and corresponding protein abundance was observed for 15 of the identified proteins, with genes encoding the majority of proteins (14) negatively regulated in stressed roots. Proteins identified in this study offer potential for the genetic improvement of cultivated peanut for drought tolerance. SIGNIFICANCE: The comparison of protein abundance and corresponding transcript expression levels (RNA-seq and qRT-PCR) revealed that 15 of the identified proteins showed similar expression behavior, with the majority (14 proteins) negatively regulated in stressed roots. Chitinase-2 (Cht2) was the only protein with an upregulation behavior in all approaches. These proteins appear to play an important role in drought tolerance in A. duranensis and may be further explored in peanut genetic breeding programs.
Assuntos
Arachis/metabolismo , Resistência à Doença , Regulação da Expressão Gênica de Plantas , Proteínas de Plantas/biossíntese , Raízes de Plantas/metabolismo , Arachis/genética , Desidratação/genética , Desidratação/metabolismo , Perfilação da Expressão Gênica , Proteínas de Plantas/genética , Raízes de Plantas/genética , ProteômicaRESUMO
Negative energy balance promotes physiological adaptations that ensure the survival of animals. The hypothalamic-pituitary-thyroid axis regulates basal energy expenditure and its down-regulating adaptation to negative energy balance is well described: in fasting, the serum content of thyrotrophin (TSH) and thyroid hormones (TH) decreases, enhancing the survival odds of individuals. By contrast, dehydration-induced anorexic (DIA) rats present an impaired hypothalamic-pituitary-thyroid (HPT) axis adaptation despite their negative energy balance: increased circulating TSH levels. The implication of cocaine- and amphetamine-regulated transcript (CART), an anorexic peptide, in HPT axis function impairment and food-avoidance behaviour displayed by DIA animals is unknown. Because CART is co-expressed with the peptide that regulates the HPT axis in hypophysiotrophic paraventricular nucleus (PVN) neurones (TSH-releasing hormone), we analysed CART expression and possible implications with respect to high TSH levels of DIA animals. We examined whether changes in CART expression from the lateral hypothalamic area (LHA) and arcuate nucleus (ARC) could participate in food-avoidance of DIA rats. DIA and forced-food restricted (FFR) animals reduced their body weight and food intake. FFR rats had a down-regulation of their HPT axis (reduced serum TH and TSH content), whereas DIA animals had reduced TH but increased TSH levels. CART mRNA expression in the ARC decreased similarly between experimental groups and diminished in anterior, medial PVN and in LHA of FFR animals, whereas DIA animals showed unchanged levels. This impaired CART mRNA expression in the anterior PVN and LHA could be related to the aberrant feeding behaviour of DIA rats but not to their deregulated HPT axis function.
Assuntos
Anfetaminas/farmacologia , Anorexia/genética , Cocaína/farmacologia , Região Hipotalâmica Lateral/efeitos dos fármacos , Núcleo Hipotalâmico Paraventricular/efeitos dos fármacos , Transcrição Gênica/efeitos dos fármacos , Animais , Anorexia/etiologia , Regulação do Apetite/genética , Núcleo Arqueado do Hipotálamo/metabolismo , Núcleo Arqueado do Hipotálamo/fisiopatologia , Aprendizagem da Esquiva , Peso Corporal/genética , Desidratação/complicações , Desidratação/genética , Comportamento Alimentar , Região Hipotalâmica Lateral/metabolismo , Masculino , Proteínas do Tecido Nervoso/genética , Núcleo Hipotalâmico Paraventricular/metabolismo , Ratos , Hormônios Tireóideos/sangue , Tireotropina/sangueRESUMO
The present study evaluated the physiological, molecular and hormonal parameters from scion/rootstock interaction of citrus plants during recurrent water deficit. Responses of the Valencia (VO) scion variety grafted on two rootstocks with different soil water extraction capacities, Rangpur Lime (RL) and Sunki Maravilha (SM), during three successive periods of water deficit: plants exposed to a single episode of water deficit (WD1) and plants exposed to two (WD2) and three (WD3) recurrent periods of WD were compared. The combinations VO/RL and VO/SM presented polymorphic alterations of epigenetic marks and hormonal (i.e. abscisic acid, auxins and salicylicacid) profiles, which were particularly prominent when VO/SM plantswere exposed toWD3 treatment. Upon successive drought events, the VO/SM combination presented acclimatization characteristics that enable higher tolerance to water deficit by increasing transpiration (E), stomatal conductance (g s ) and photosynthetic rate (A), which in turn may have facilitated the whole plant survival. Besides providing comprehensive data on the scion/rootstock interactions upon successive stress events, this study brings the first dataset suggesting that epigenetic alterations in citrus plants triggered by recurrent water deficit lead to improved drought tolerance in this crop species.