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1.
Plant Signal Behav ; 19(1): 2371693, 2024 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-38923879

RESUMO

One of the main signal transduction pathways that modulate plant growth and stress responses, including drought, is the action of phytohormones. Recent advances in omics approaches have facilitated the exploration of plant genomes. However, the molecular mechanisms underlying the response in the crown of barley, which plays an essential role in plant performance under stress conditions and regeneration after stress treatment, remain largely unclear. The objective of the present study was the elucidation of drought-induced molecular reactions in the crowns of different barley phytohormone mutants. We verified the hypothesis that defects of gibberellins, brassinosteroids, and strigolactones action affect the transcriptomic, proteomic, and hormonal response of barley crown to the transitory drought influencing plant development under stress. Moreover, we assumed that due to the strong connection between strigolactones and branching the hvdwarf14.d mutant, with dysfunctional receptor of strigolactones, manifests the most abundant alternations in crowns and phenotype under drought. Finally, we expected to identify components underlying the core response to drought which are independent of the genetic background. Large-scale analyses were conducted using gibberellins-biosynthesis, brassinosteroids-signaling, and strigolactones-signaling mutants, as well as reference genotypes. Detailed phenotypic evaluation was also conducted. The obtained results clearly demonstrated that hormonal disorders caused by mutations in the HvGA20ox2, HvBRI1, and HvD14 genes affected the multifaceted reaction of crowns to drought, although the expression of these genes was not induced by stress. The study further detected not only genes and proteins that were involved in the drought response and reacted specifically in mutants compared to the reaction of reference genotypes and vice versa, but also the candidates that may underlie the genotype-universal stress response. Furthermore, candidate genes involved in phytohormonal interactions during the drought response were identified. We also found that the interplay between hormones, especially gibberellins and auxins, as well as strigolactones and cytokinins may be associated with the regulation of branching in crowns exposed to drought. Overall, the present study provides novel insights into the molecular drought-induced responses that occur in barley crowns.


Assuntos
Secas , Hordeum , Mutação , Reguladores de Crescimento de Plantas , Hordeum/genética , Hordeum/metabolismo , Hordeum/crescimento & desenvolvimento , Reguladores de Crescimento de Plantas/metabolismo , Mutação/genética , Giberelinas/metabolismo , Regulação da Expressão Gênica de Plantas , Brassinosteroides/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Estresse Fisiológico/genética , Lactonas/metabolismo
2.
Int J Mol Sci ; 25(9)2024 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-38731903

RESUMO

To assess the impact of Enchytraeidae (potworms) on the functioning of the decomposer system, knowledge of the feeding preferences of enchytraeid species is required. Different food preferences can be explained by variations in enzymatic activities among different enchytraeid species, as there are no significant differences in the morphology or anatomy of their alimentary tracts. However, it is crucial to distinguish between the contribution of microbial enzymes and the animal's digestive capacity. Here, we computationally analyzed the endogenous digestive enzyme genes in Enchytraeus albidus. The analysis was based on RNA-Seq of COI-monohaplotype culture (PL-A strain) specimens, utilizing transcriptome profiling to determine the trophic position of the species. We also corroborated the results obtained using transcriptomics data from genetically heterogeneous freeze-tolerant strains. Our results revealed that E. albidus expresses a wide range of glycosidases, including GH9 cellulases and a specific digestive SH3b-domain-containing i-type lysozyme, previously described in the earthworm Eisenia andrei. Therefore, E. albidus combines traits of both primary decomposers (primary saprophytophages) and secondary decomposers (sapro-microphytophages/microbivores) and can be defined as an intermediate decomposer. Based on assemblies of publicly available RNA-Seq reads, we found close homologs for these cellulases and i-type lysozymes in various clitellate taxa, including Crassiclitellata and Enchytraeidae.


Assuntos
Perfilação da Expressão Gênica , Oligoquetos , Transcriptoma , Animais , Transcriptoma/genética , Perfilação da Expressão Gênica/métodos , Oligoquetos/genética , Oligoquetos/enzimologia , Digestão/genética , Glicosídeo Hidrolases/genética , Glicosídeo Hidrolases/metabolismo
3.
Biochimie ; 221: 38-59, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38242278

RESUMO

Although enchytraeids have gained popularity in scientific research, fundamental questions regarding their feeding ecology and biology remain largely unexplored. This study investigates α-amylases, major digestive enzymes responsible for hydrolyzing starch and similar polysaccharides into sugars, in Enchytraeus albidus. Genetic data related to α-amylases is currently lacking for the family Enchytraeidae but also for the entire Annelida. To detect and identify coding sequences of the expressed α-amylase genes in COI-monohaplotype culture (PL-A strain) of E. albidus, we used classical "gene fishing" and transcriptomic approaches. We also compared coding sequence variants of α-amylase retrieved from transcriptomic data related to freeze-tolerant strains. Our results reveal that E. albidus possesses two distinct α-amylase genes (Amy I and Amy II) that are homologs to earthworm Eisenia fetida Ef-Amy genes. Different strains of E. albidus possess distinctive alleles of α-amylases with unique SNP patterns specific to a particular strain. Unlike Amy II, Amy I seems to be a highly polymorphic and multicopy gene. The domain architecture of the putative Amy proteins was found the same as for classical animal α-amylases with ABC-domains. A characteristic feature of Amy II is the lack of GHGA motif in the flexible loop region, similarly to many insect amylases. We identified "Enchytraeus-Eisenia type" α-amylase homologs in other clitellates and polychaetes, indicating the ancestral origin of Amy I/II proteins in Annelida. This study provides the first insight into the endogenous non-proteolytic digestive enzyme genes in potworms, discusses the evolution of Amy α-amylases in Annelida, and explores phylogenetic implications.


Assuntos
alfa-Amilases , alfa-Amilases/genética , alfa-Amilases/metabolismo , alfa-Amilases/química , Animais , Evolução Molecular , Filogenia , DNA Complementar/genética , Anelídeos/genética , Anelídeos/enzimologia , Oligoquetos/genética , Oligoquetos/enzimologia , Sequência de Aminoácidos
4.
Curr Biol ; 33(23): R1246-R1261, 2023 12 04.
Artigo em Inglês | MEDLINE | ID: mdl-38052178

RESUMO

Climate change threatens global food and nutritional security through negative effects on crop growth and agricultural productivity. Many countries have adopted ambitious climate change mitigation and adaptation targets that will exacerbate the problem, as they require significant changes in current agri-food systems. In this review, we provide a roadmap for improved crop production that encompasses the effective transfer of current knowledge into plant breeding and crop management strategies that will underpin sustainable agriculture intensification and climate resilience. We identify the main problem areas and highlight outstanding questions and potential solutions that can be applied to mitigate the impacts of climate change on crop growth and productivity. Although translation of scientific advances into crop production lags far behind current scientific knowledge and technology, we consider that a holistic approach, combining disciplines in collaborative efforts, can drive better connections between research, policy, and the needs of society.


Assuntos
Mudança Climática , Produtos Agrícolas , Melhoramento Vegetal , Agricultura , Produção Agrícola
5.
Front Plant Sci ; 14: 1247853, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37941662

RESUMO

Introduction: Breeding barley cultivars adapted to drought requires in-depth knowledge on physiological drought responses. Methods: We used a high-throughput functional phenotyping platform to examine the response of four high-yielding European spring barley cultivars to a standardized drought treatment imposed around flowering. Results: Cv. Chanell showed a non-conserving water-use behavior with high transpiration and maximum productivity under well-watered conditions but rapid transpiration decrease under drought. The poor recovery upon re-irrigation translated to large yield losses. Cv. Baronesse showed the most water-conserving behavior, with the lowest pre-drought transpiration and the most gradual transpiration reduction under drought. Its good recovery (resilience) prevented large yield losses. Cv. Formula was less conserving than cv. Baronesse and produced low yet stable yields. Cv. RGT's dynamic water use with high transpiration under ample water supply and moderate transpiration decrease under drought combined with high resilience secured the highest and most stable yields. Discussion: Such a dynamic water-use behavior combined with higher drought resilience and favorable root traits could potentially create an ideotype for intermediate drought. Prospective studies will examine these results in field experiments and will use the newly gained understanding on water use in barley to improve process descriptions in crop simulation models to support crop model-aided ideotype design.

6.
Plant Sci ; 337: 111894, 2023 Oct 08.
Artigo em Inglês | MEDLINE | ID: mdl-37813193

RESUMO

NAC family gene - SNAC1 (Stress-responsive NAC1) is responsive to drought, salt, cold stress, and ABA. It acts as a regulator in mediating tolerance to abiotic stress through different pathways. Abiotic stress, among them drought and salinity, are adverse factors for plant growth and crop productivity. SNAC1 was an object of high interest according to the effect of improved drought and salt tolerance when overexpressed in different plant species such as rice, wheat, barley, cotton, maize, banana, or oat. SNAC1 functions by regulating the expression of genes that contain the NAC Recognized Sequence (NACRS) within their promoter region. This gene is induced by drought, specifically in guard cells. Its downstream targets have been identified. The role of SNAC1 in molecular and physiological responses during abiotic stress has been proposed, but this knowledge still needs to be expanded. Here, we describe recent advances in understanding the action of SNAC1 in adapting plants to abiotic stress.

7.
Front Plant Sci ; 14: 1270180, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37849845

RESUMO

Stomata, key gatekeepers of plant hydration, have long been known to play a pivotal role in mitigating the impacts of abiotic stressors. However, the complex molecular mechanisms underscoring this role remain unresolved fully and continue to be the subject of research. In the context of water-use efficiency (WUE), a key indicator of a plant's ability to conserve water, this aspect links intrinsically with stomatal behavior. Given the pivotal role of stomata in modulating water loss, it can be argued that the complex mechanisms governing stomatal development and function will significantly influence a plant's WUE under different abiotic stress conditions. Addressing these calls for a concerted effort to strengthen plant adaptability through advanced, targeted research. In this vein, recent studies have illuminated how specific stressors trigger alterations in gene expression, orchestrating changes in stomatal pattern, structure, and opening. This reveals a complex interplay between stress stimuli and regulatory sequences of essential genes implicated in stomatal development, such as MUTE, SPCH, and FAMA. This review synthesizes current discoveries on the molecular foundations of stomatal development and behavior in various stress conditions and their implications for WUE. It highlights the imperative for continued exploration, as understanding and leveraging these mechanisms guarantee enhanced plant resilience amid an ever-changing climatic landscape.

8.
BMC Plant Biol ; 23(1): 445, 2023 Sep 22.
Artigo em Inglês | MEDLINE | ID: mdl-37735356

RESUMO

BACKGROUND: Drought is a major environmental stress that affects crop productivity worldwide. Although previous research demonstrated links between strigolactones (SLs) and drought, here we used barley (Hordeum vulgare) SL-insensitive mutant hvd14 (dwarf14) to scrutinize the SL-dependent mechanisms associated with water deficit response. RESULTS: We have employed a combination of transcriptomics, proteomics, phytohormonomics analyses, and physiological data to unravel differences between wild-type and hvd14 plants under drought. Our research revealed that drought sensitivity of hvd14 is related to weaker induction of abscisic acid-responsive genes/proteins, lower jasmonic acid content, higher reactive oxygen species content, and lower wax biosynthetic and deposition mechanisms than wild-type plants. In addition, we identified a set of transcription factors (TFs) that are exclusively drought-induced in the wild-type barley. CONCLUSIONS: Critically, we resolved a comprehensive series of interactions between the drought-induced barley transcriptome and proteome responses, allowing us to understand the profound effects of SLs in alleviating water-limiting conditions. Several new avenues have opened for developing barley more resilient to drought through the information provided. Moreover, our study contributes to a better understanding of the complex interplay between genes, proteins, and hormones in response to drought, and underscores the importance of a multidisciplinary approach to studying plant stress response mechanisms.


Assuntos
Hordeum , Hordeum/genética , Secas , Multiômica , Percepção
9.
Trends Plant Sci ; 28(8): 873-875, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37208202

RESUMO

Recently. Mei et al. discovered the molecular mechanism behind the synergistic action of auxins and jasmonates in enhancing the role of abscisic acid (ABA) in seed germination. They found that JASMONATE-ZIM DOMAIN (JAZ) proteins interact with AUXIN RESPONSE FACTOR (ARF)-16 to mediate auxin-jasmonic acid (JA) crosstalk. Furthermore, they revealed that ARF16 interacts with ABSCISIC ACID INSENSITIVE (ABI)-5 and positively modulates ABA responses at seed germination.


Assuntos
Ácido Abscísico , Proteínas de Arabidopsis , Ácido Abscísico/metabolismo , Ácidos Indolacéticos/metabolismo , Germinação , Sementes/genética , Sementes/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Regulação da Expressão Gênica de Plantas
10.
Front Plant Sci ; 14: 1144990, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37008485

RESUMO

Seed germination is an essential step in a plant's life cycle. It is controlled by complex physiological, biochemical, and molecular mechanisms and external factors. Alternative splicing (AS) is a co-transcriptional mechanism that regulates gene expression and produces multiple mRNA variants from a single gene to modulate transcriptome diversity. However, little is known about the effect of AS on the function of generated protein isoforms. The latest reports indicate that alternative splicing (AS), the relevant mechanism controlling gene expression, plays a significant role in abscisic acid (ABA) signaling. In this review, we present the current state of the art about the identified AS regulators and the ABA-related changes in AS during seed germination. We show how they are connected with the ABA signaling and the seed germination process. We also discuss changes in the structure of the generated AS isoforms and their impact on the functionality of the generated proteins. Also, we point out that the advances in sequencing technology allow for a better explanation of the role of AS in gene regulation by more accurate detection of AS events and identification of full-length splicing isoforms.

11.
Trends Plant Sci ; 28(5): 537-543, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-36740490

RESUMO

Greenhouse gas (GHG) emissions have created a global climate crisis which requires immediate interventions to mitigate the negative effects on all aspects of life on this planet. As current agriculture and land use contributes up to 25% of total GHG emissions, plant scientists take center stage in finding possible solutions for a transition to sustainable agriculture and land use. In this article, the PlantACT! (Plants for climate ACTion!) initiative of plant scientists lays out a road map of how and in which areas plant scientists can contribute to finding immediate, mid-term, and long-term solutions, and what changes are necessary to implement these solutions at the personal, institutional, and funding levels.


Assuntos
Agricultura , Gases de Efeito Estufa , Gases de Efeito Estufa/análise , Plantas , Mudança Climática , Efeito Estufa
13.
BMC Genomics ; 23(1): 177, 2022 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-35246029

RESUMO

BACKGROUND: High temperature shock is becoming increasingly common in our climate, affecting plant growth and productivity. The ability of a plant to survive stress is a complex phenomenon. One of the essential tissues for plant performance under various environmental stimuli is the crown. However, the molecular characterization of this region remains poorly investigated. Gibberellins play a fundamental role in whole-plant stature formation. This study identified plant stature modifications and crown-specific transcriptome re-modeling in gibberellin-deficient barley sdw1.a (BW827) and sdw1.d (BW828) mutants exposed to increased temperature. RESULTS: The deletion around the sdw1 gene in BW827 was found to encompass at least 13 genes with primarily regulatory functions. A bigger genetic polymorphism of BW828 than of BW827 in relation to wild type was revealed. Transcriptome-wide sequencing (RNA-seq) revealed several differentially expressed genes involved in gibberellin metabolism and heat response located outside of introgression regions. It was found that HvGA20ox4, a paralogue of the HvGA20ox2 gene, was upregulated in BW828 relative to other genotypes, which manifested as basal internode elongation. The transcriptome response to elevated temperature differed in the crown of sdw1.a and sdw1.d mutants; it was most contrasting for HvHsf genes upregulated under elevated temperature in BW828, whereas those specific to BW827 were downregulated. In-depth examination of sdw1 mutants revealed also some differences in their phenotypes and physiology. CONCLUSIONS: We concluded that despite the studied sdw1 mutants being genetically related, their heat response seemed to be genotype-specific and observed differences resulted from genetic background diversity rather than single gene mutation, multiple gene deletion, or allele-specific expression of the HvGA20ox2 gene. Differences in the expressional reaction of genes to heat in different sdw1 mutants, found to be independent of the polymorphism, could be further explained by in-depth studies of the regulatory factors acting in the studied system. Our findings are particularly important in genetic research area since molecular response of crown tissue has been marginally investigated, and can be useful for wide genetic research of crops since barley has become a model plant for them.


Assuntos
Hordeum , Regulação da Expressão Gênica de Plantas , Genótipo , Resposta ao Choque Térmico/genética , Sequenciamento de Nucleotídeos em Larga Escala , Hordeum/genética , Fenótipo
14.
Trends Plant Sci ; 27(5): 423-425, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35249809

RESUMO

Recent reports by Qin et al. and Zhang et al. cast light on long-distance abscisic acid (ABA) transport and demonstrate that ABA has a major impact on plant growth and physiology under both non-stress and stress conditions. Insights into ABA transport may provide a means to modulate the response of plants to climate change.


Assuntos
Ácido Abscísico , Proteínas de Membrana Transportadoras , Transporte de Íons , Proteínas de Membrana Transportadoras/genética , Proteínas de Membrana Transportadoras/metabolismo , Desenvolvimento Vegetal , Plantas/metabolismo
15.
Trends Genet ; 38(4): 310-311, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-34949464

RESUMO

Many letters of the plant genetic code have been read since the first plant genome was published in 2000 for Arabidopsis. In a recent paper, Marks et al. examined 798 plant genomes and provide a current view of plant genomics in terms of the quality of the assemblies, coupled with their taxonomical and geographical distribution.


Assuntos
Arabidopsis , Genômica , Arabidopsis/genética , Genoma de Planta/genética , Plantas/genética , Análise de Sequência de DNA
16.
Cells ; 10(8)2021 08 05.
Artigo em Inglês | MEDLINE | ID: mdl-34440762

RESUMO

The core abscisic acid (ABA) signaling pathway consists of receptors, phosphatases, kinases and transcription factors, among them ABA INSENSITIVE 5 (ABI5) and ABRE BINDING FACTORs/ABRE-BINDING PROTEINs (ABFs/AREBs), which belong to the BASIC LEUCINE ZIPPER (bZIP) family and control expression of stress-responsive genes. ABI5 is mostly active in seeds and prevents germination and post-germinative growth under unfavorable conditions. The activity of ABI5 is controlled at transcriptional and protein levels, depending on numerous regulators, including components of other phytohormonal pathways. ABFs/AREBs act redundantly in regulating genes that control physiological processes in response to stress during vegetative growth. In this review, we focus on recent reports regarding ABI5 and ABFs/AREBs functions during abiotic stress responses, which seem to be partially overlapping and not restricted to one developmental stage in Arabidopsis and other species. Moreover, we point out that ABI5 and ABFs/AREBs play a crucial role in the core ABA pathway's feedback regulation. In this review, we also discuss increased stress tolerance of transgenic plants overexpressing genes encoding ABA-dependent bZIPs. Taken together, we show that ABI5 and ABFs/AREBs are crucial ABA-dependent transcription factors regulating processes essential for plant adaptation to stress at different developmental stages.


Assuntos
Ácido Abscísico/metabolismo , Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Fatores de Transcrição de Zíper de Leucina Básica/metabolismo , Desenvolvimento Vegetal , Plantas Geneticamente Modificadas/metabolismo , Estresse Fisiológico , Arabidopsis/genética , Arabidopsis/crescimento & desenvolvimento , Proteínas de Arabidopsis/genética , Fatores de Transcrição de Zíper de Leucina Básica/genética , Flores/genética , Flores/crescimento & desenvolvimento , Flores/metabolismo , Frutas/genética , Frutas/crescimento & desenvolvimento , Frutas/metabolismo , Regulação da Expressão Gênica de Plantas , Germinação , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/crescimento & desenvolvimento , Sementes/genética , Sementes/crescimento & desenvolvimento , Sementes/metabolismo , Transdução de Sinais
17.
Int J Mol Sci ; 22(3)2021 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-33494371

RESUMO

Mechanisms involved in the de-acclimation of herbaceous plants caused by warm periods during winter are poorly understood. This study identifies the genes associated with this mechanism in winter barley. Seedlings of eight accessions (four tolerant and four susceptible to de-acclimation cultivars and advanced breeding lines) were cold acclimated for three weeks and de-acclimated at 12 °C/5 °C (day/night) for one week. We performed differential expression analysis using RNA sequencing. In addition, reverse-transcription quantitative real-time PCR and enzyme activity analyses were used to investigate changes in the expression of selected genes. The number of transcripts with accumulation level changed in opposite directions during acclimation and de-acclimation was much lower than the number of transcripts with level changed exclusively during one of these processes. The de-acclimation-susceptible accessions showed changes in the expression of a higher number of functionally diverse genes during de-acclimation. Transcripts associated with stress response, especially oxidoreductases, were the most abundant in this group. The results provide novel evidence for the distinct molecular regulation of cold acclimation and de-acclimation. Upregulation of genes controlling developmental changes, typical for spring de-acclimation, was not observed during mid-winter de-acclimation. Mid-winter de-acclimation seems to be perceived as an opportunity to regenerate after stress. Unfortunately, it is competitive to remain in the cold-acclimated state. This study shows that the response to mid-winter de-acclimation is far more expansive in de-acclimation-susceptible cultivars, suggesting that a reduced response to the rising temperature is crucial for de-acclimation tolerance.


Assuntos
Aclimatação/genética , Temperatura Baixa , Estudos de Associação Genética , Hordeum/fisiologia , Estações do Ano , Biologia Computacional/métodos , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Ontologia Genética , Transcriptoma
18.
Plant Sci ; 300: 110593, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33180718

RESUMO

CBP20 (Cap-Binding Protein 20) encodes a small subunit of nuclear Cap-Binding Complex (nCBC) that together with CBP80 binds mRNA cap. We previously described barley hvcbp20.ab mutant that demonstrated higher leaf water content and faster stomatal closure than the WT after drought stress. Hence, we presumed that the better water-saving mechanism in hvcbp20.ab may result from the lower permeability of epidermis that together with stomata action limit the water evaporation under drought stress. We asked whether hvcbp20.ab exhibited any differences in wax load on the leaf surface when subjected to drought in comparison to WT cv. 'Sebastian'. To address this question, we investigated epicuticular wax structure and chemical composition under drought stress in hvcbp20.ab mutant and its WT. We showed that hvcbp20.ab mutant exhibited the increased deposition of cuticular wax. Moreover, our gene expression results suggested a role of HvCBP20 as a negative regulator of both, the biosynthesis of waxes at the level of alkane-forming, and waxes transportation. Interestingly, we also observed increased wax deposition in Arabidopsis cbp20 mutant exposed to drought, which allowed us to describe the CBP20-regulated epicuticular wax accumulation under drought stress in a wider evolutionarily context.


Assuntos
Desidratação/fisiopatologia , Hordeum/genética , Hordeum/metabolismo , Epiderme Vegetal/metabolismo , Proteínas de Plantas/metabolismo , Proteínas de Ligação ao Cap de RNA/metabolismo , Água/metabolismo , Desidratação/genética , Regulação da Expressão Gênica de Plantas , Mutação , Epiderme Vegetal/genética , Proteínas de Plantas/genética , Proteínas de Ligação a RNA/metabolismo , Estresse Fisiológico/genética , Fatores de Transcrição/metabolismo
19.
Front Plant Sci ; 11: 1138, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32849699

RESUMO

ABA INSENSITIVE 5 (ABI5) is a basic leucine zipper (bZIP) transcription factor which acts in the abscisic acid (ABA) network and is activated in response to abiotic stresses. However, the precise role of barley (Hordeum vulgare) ABI5 in ABA signaling and its function under stress remains elusive. Here, we show that HvABI5 is involved in ABA-dependent regulation of barley response to drought stress. We identified barley TILLING mutants carrying different alleles in the HvABI5 gene and we studied in detail the physiological and molecular response to drought and ABA for one of them. The hvabi5.d mutant, carrying G1751A transition, was insensitive to ABA during seed germination, yet it showed the ability to store more water than its parent cv. "Sebastian" (WT) in response to drought stress. The drought-tolerant phenotype of hvabi5.d was associated with better membrane protection, higher flavonoid content, and faster stomatal closure in the mutant under stress compared to the WT. The microarray transcriptome analysis revealed up-regulation of genes associated with cell protection mechanisms in the mutant. Furthermore, HvABI5 target genes: HVA1 and HVA22 showed higher activity after drought, which may imply better adaptation of hvabi5.d to stress. On the other hand, chlorophyll content in hvabi5.d was lower than in WT, which was associated with decreased photosynthesis efficiency observed in the mutant after drought treatment. To verify that HvABI5 acts in the ABA-dependent manner we analyzed expression of selected genes related to ABA pathway in hvabi5.d and its WT parent after drought and ABA treatments. The expression of key genes involved in ABA metabolism and signaling differed in the mutant and the WT under stress. Drought-induced increase of expression of HvNCED1, HvBG8, HvSnRK2.1, and HvPP2C4 genes was 2-20 times higher in hvabi5.d compared to "Sebastian". We also observed a faster stomatal closure in hvabi5.d and much higher induction of HvNCED1 and HvSnRK2.1 genes after ABA treatment. Together, these findings demonstrate that HvABI5 plays a role in regulation of drought response in barley and suggest that HvABI5 might be engaged in the fine tuning of ABA signaling by a feedback regulation between biosynthetic and signaling events. In addition, they point to different mechanisms of HvABI5 action in regulating drought response and seed germination in barley.

20.
Trends Plant Sci ; 25(10): 950-952, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32646720

RESUMO

Epicuticular waxes serve as a protective layer on plant aerial surfaces. The chemical reactions of wax biosynthesis are well understood, but little is known about the underlying regulatory mechanisms. New data from Yang et al. and Lange et al. argue that RNA degradation and silencing play a key role in regulating the content of alkanes, the most abundant components of wax.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/genética , Complexo Multienzimático de Ribonucleases do Exossomo , RNA , Ceras
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