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1.
Plant Cell ; 2024 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-39197037

RESUMO

Photorespiration is an energetically costly metabolic pathway in plants that responds to environmental stresses. The molecular basis of the regulation of the photorespiratory cycle under stress conditions remains unclear. Here, we discovered that FERONIA (FER) regulates photorespiratory flow under salt stress in Arabidopsis (Arabidopsis thaliana). FER mutation results in hypersensitivity to salt stress, but disruption of ferredoxin-dependent glutamate synthase 1 (GLU1), an enzyme that participates in the photorespiratory pathway by producing glutamate, greatly suppresses fer-4 hypersensitivity to salt stress primarily due to reduced glycine yield. In contrast, disrupting mitochondrial serine hydroxymethyltransferase1 (SHM1), which is supposed to increase glycine levels by hampering the conversion of glycine to serine in the photorespiratory cycle, aggravates fer-4 hypersensitivity to salt stress. Biochemical data show that FER interacts with and phosphorylates SHM1, and this phosphorylation modulates SHM1 stability. Additionally, the production of proline and its intermediate △1-pyrroline-5-carboxylate (P5C), which are both synthesized from glutamate, also contributes to fer-4 hypersensitivity to salt stress. In conclusion, this study elucidates the functional mechanism of FER in regulating salt tolerance by modulating photorespiratory flux, which greatly broadens our understanding of how plants adapt to high salinity.

2.
Plant Cell ; 35(1): 201-217, 2023 01 02.
Artigo em Inglês | MEDLINE | ID: mdl-36149287

RESUMO

Salt stress simultaneously causes ionic toxicity, osmotic stress, and oxidative stress, which directly impact plant growth and development. Plants have developed numerous strategies to adapt to saline environments. Whereas some of these strategies have been investigated and exploited for crop improvement, much remains to be understood, including how salt stress is perceived by plants and how plants coordinate effective responses to the stress. It is, however, clear that the plant cell wall is the first contact point between external salt and the plant. In this context, significant advances in our understanding of halotropism, cell wall synthesis, and integrity surveillance, as well as salt-related cytoskeletal rearrangements, have been achieved. Indeed, molecular mechanisms underpinning some of these processes have recently been elucidated. In this review, we aim to provide insights into how plants respond and adapt to salt stress, with a special focus on primary cell wall biology in the model plant Arabidopsis thaliana.


Assuntos
Parede Celular , Estresse Salino , Arabidopsis/metabolismo , Proteínas de Arabidopsis/metabolismo , Parede Celular/metabolismo , Regulação da Expressão Gênica de Plantas , Plantas/metabolismo , Estresse Salino/fisiologia
3.
J Exp Bot ; 75(7): 1852-1871, 2024 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-38226463

RESUMO

Drought tolerance is a complex trait in soybean that is controlled by polygenetic quantitative trait loci (QTLs). In this study, wilting score, days-to-wilting, leaf relative water content, and leaf relative conductivity were used to identify QTLs associated with drought tolerance in recombinant inbred lines derived from a cross between a drought-sensitive variety, Lin, and a drought-tolerant variety, Meng. A total of 33 drought-tolerance QTLs were detected. Of these 17 were major QTLs. In addition, 15 were novel drought-tolerance QTLs. The most predominant QTL was on chromosome 11. This was detected in at least three environments. The overlapped mapping interval of the four measured traits was 0.2 cM in genetic distance (about 220 kb in physical length). Glyma.11g143500 (designated as GmUAA6), which encodes a UDP-N-acetylglucosamine transporter, was identified as the most likely candidate gene. The allele of GmUAA6 from Lin (GmUAA6Lin) was associated with improved soybean drought tolerance. Overexpression of GmUAA6Lin in Arabidopsis and soybean hairy roots enhanced drought tolerance. Furthermore, a 3-bp insertion/deletion (InDel) in the coding sequence of GmUAA6 explained up to 49.9% of the phenotypic variation in drought tolerance-related traits, suggesting that this InDel might be used in future marker-assisted selection of drought-tolerant lines in soybean breeding programs.


Assuntos
Glycine max , Locos de Características Quantitativas , Mapeamento Cromossômico , Resistência à Seca , Melhoramento Vegetal , Fenótipo , Secas
4.
J Integr Plant Biol ; 2024 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-39031490

RESUMO

Generation of crops with low phytic acid (myo-inositol-1,2,3,4,5,6-hexakisphosphate (InsP6)) is an important breeding direction, but such plants often display less desirable agronomic traits. In this study, through ethyl methanesulfonate-mediated mutagenesis, we found that inositol 1,3,4-trisphosphate 5/6-kinase 4 (ITPK4), which is essential for producing InsP6, is a critical regulator of salt tolerance in Arabidopsis. Loss of function of ITPK4 gene leads to reduced root elongation under salt stress, which is primarily because of decreased root meristem length and reduced meristematic cell number. The itpk4 mutation also results in increased root hair density and increased accumulation of reactive oxygen species during salt exposure. RNA sequencing assay reveals that several auxin-responsive genes are down-regulated in the itpk4-1 mutant compared to the wild-type. Consistently, the itpk4-1 mutant exhibits a reduced auxin level in the root tip and displays compromised gravity response, indicating that ITPK4 is involved in the regulation of the auxin signaling pathway. Through suppressor screening, it was found that mutation of Multidrug Resistance Protein 5 (MRP5)5 gene, which encodes an ATP-binding cassette (ABC) transporter required for transporting InsP6 from the cytoplasm into the vacuole, fully rescues the salt hypersensitivity of the itpk4-1 mutant, but in the itpk4-1 mrp5 double mutant, InsP6 remains at a very low level. These results imply that InsP6 homeostasis rather than its overall amount is beneficial for stress tolerance in plants. Collectively, this study uncovers a pair of gene mutations that confer low InsP6 content without impacting stress tolerance, which offers a new strategy for creating "low-phytate" crops.

5.
Proc Natl Acad Sci U S A ; 117(6): 3270-3280, 2020 02 11.
Artigo em Inglês | MEDLINE | ID: mdl-31992638

RESUMO

Protein kinases are major regulatory components in almost all cellular processes in eukaryotic cells. By adding phosphate groups, protein kinases regulate the activity, localization, protein-protein interactions, and other features of their target proteins. It is known that protein kinases are central components in plant responses to environmental stresses such as drought, high salinity, cold, and pathogen attack. However, only a few targets of these protein kinases have been identified. Moreover, how these protein kinases regulate downstream biological processes and mediate stress responses is still largely unknown. In this study, we introduce a strategy based on isotope-labeled in vitro phosphorylation reactions using in vivo phosphorylated peptides as substrate pools and apply this strategy to identify putative substrates of nine protein kinases that function in plant abiotic and biotic stress responses. As a result, we identified more than 5,000 putative target sites of osmotic stress-activated SnRK2.4 and SnRK2.6, abscisic acid-activated protein kinases SnRK2.6 and casein kinase 1-like 2 (CKL2), elicitor-activated protein kinase CDPK11 and MPK6, cold-activated protein kinase MPK6, H2O2-activated protein kinase OXI1 and MPK6, and salt-induced protein kinase SOS1 and MPK6, as well as the low-potassium-activated protein kinase CIPK23. These results provide comprehensive information on the role of these protein kinases in the control of cellular activities and could be a valuable resource for further studies on the mechanisms underlying plant responses to environmental stresses.


Assuntos
Proteínas de Arabidopsis/metabolismo , Mapas de Interação de Proteínas/fisiologia , Proteínas Quinases/metabolismo , Proteoma/metabolismo , Estresse Fisiológico/fisiologia , Arabidopsis/metabolismo , Arabidopsis/fisiologia , Fosforilação , Mapeamento de Interação de Proteínas
6.
BMC Plant Biol ; 21(1): 309, 2021 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-34210268

RESUMO

BACKGROUND: Phytohormone abscisic acid (ABA) is involved in the regulation of a wide range of biological processes. In Arabidopsis, it has been well-known that SnRK2s are the central components of the ABA signaling pathway that control the balance between plant growth and stress response, but the functions of ZmSnRK2 in maize are rarely reported. Therefore, the study of ZmSnRK2 is of great importance to understand the ABA signaling pathways in maize. RESULTS: In this study, 14 ZmSnRK2 genes were identified in the latest version of maize genome database. Phylogenetic analysis revealed that ZmSnRK2s are divided into three subclasses based on their diversity of C-terminal domains. The exon-intron structures, phylogenetic, synteny and collinearity analysis indicated that SnRK2s, especially the subclass III of SnRK2, are evolutionally conserved in maize, rice and Arabidopsis. Subcellular localization showed that ZmSnRK2 proteins are localized in the nucleus and cytoplasm. The RNA-Seq datasets and qRT-PCR analysis showed that ZmSnRK2 genes exhibit spatial and temporal expression patterns during the growth and development of different maize tissues, and the transcript levels of some ZmSnRK2 genes in kernel are significantly induced by ABA and sucrose treatment. In addition, we found that ZmSnRK2.10, which belongs to subclass III, is highly expressed in kernel and activated by ABA. Overexpression of ZmSnRK2.10 partially rescued the ABA-insensitive phenotype of snrk2.2/2.3 double and snrk2.2/2.3/2.6 triple mutants and led to delaying plant flowering in Arabidopsis. CONCLUSION: The SnRK2 gene family exhibits a high evolutionary conservation and has expanded with whole-genome duplication events in plants. The ZmSnRK2s expanded in maize with whole-genome and segmental duplication, not tandem duplication. The expression pattern analysis of ZmSnRK2s in maize offers important information to study their functions. Study of the functions of ZmSnRK.10 in Arabidopsis suggests that the ABA-dependent members of SnRK2s are evolutionarily conserved in plants. Our study elucidated the structure and evolution of SnRK2 genes in plants and provided a basis for the functional study of ZmSnRK2s protein in maize.


Assuntos
Ácido Abscísico/metabolismo , Genes de Plantas , Transdução de Sinais , Zea mays/genética , Zea mays/metabolismo , Arabidopsis/genética , Sequência de Bases , Núcleo Celular/metabolismo , Cromossomos de Plantas/genética , Evolução Molecular , Duplicação Gênica , Regulação da Expressão Gênica de Plantas , Mutação/genética , Fenótipo , Filogenia , Transdução de Sinais/genética , Frações Subcelulares/metabolismo , Sintenia/genética
7.
Proc Natl Acad Sci U S A ; 115(51): 13123-13128, 2018 12 18.
Artigo em Inglês | MEDLINE | ID: mdl-30514814

RESUMO

The perception and relay of cell-wall signals are critical for plants to regulate growth and stress responses, but the underlying mechanisms are poorly understood. We found that the cell-wall leucine-rich repeat extensins (LRX) 3/4/5 are critical for plant salt tolerance in Arabidopsis The LRXs physically associate with the RAPID ALKALINIZATION FACTOR (RALF) peptides RALF22/23, which in turn interact with the plasma membrane-localized receptor-like protein kinase FERONIA (FER). The lrx345 triple mutant as well as fer mutant plants display retarded growth and salt hypersensitivity, which are mimicked by overexpression of RALF22/23 Salt stress promotes S1P protease-dependent release of mature RALF22 peptides. Treatment of roots with mature RALF22/23 peptides or salt stress causes the internalization of FER. Our results suggest that the LRXs, RALFs, and FER function as a module to transduce cell-wall signals to regulate plant growth and salt stress tolerance.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/fisiologia , Desenvolvimento Vegetal , Plantas Geneticamente Modificadas/fisiologia , Proteínas/metabolismo , Tolerância ao Sal/genética , Estresse Fisiológico , Proteínas de Arabidopsis/genética , Parede Celular/metabolismo , Regulação da Expressão Gênica de Plantas , Leucina/química , Proteínas de Repetições Ricas em Leucina , Proteínas/genética , Plantas Tolerantes a Sal/fisiologia , Transdução de Sinais
8.
Int J Mol Sci ; 22(6)2021 Mar 23.
Artigo em Inglês | MEDLINE | ID: mdl-33806816

RESUMO

Cell wall biosynthesis is a complex biological process in plants. In the rapidly growing cells or in the plants that encounter a variety of environmental stresses, the compositions and the structure of cell wall can be dynamically changed. To constantly monitor cell wall status, plants have evolved cell wall integrity (CWI) maintenance system, which allows rapid cell growth and improved adaptation of plants to adverse environmental conditions without the perturbation of cell wall organization. Salt stress is one of the abiotic stresses that can severely disrupt CWI, and studies have shown that the ability of plants to sense and maintain CWI is important for salt tolerance. In this review, we highlight the roles of CWI in salt tolerance and the mechanisms underlying the maintenance of CWI under salt stress. The unsolved questions regarding the association between the CWI and salt tolerance are discussed.


Assuntos
Parede Celular/fisiologia , Fenômenos Fisiológicos Vegetais , Salinidade , Tolerância ao Sal , Adaptação Fisiológica , Celulose/biossíntese , Regulação da Expressão Gênica de Plantas , Glicoproteínas/metabolismo , Concentração de Íons de Hidrogênio , Espaço Intracelular/metabolismo , Oxirredução , Transdução de Sinais
9.
New Phytol ; 228(5): 1573-1590, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-32619295

RESUMO

CDK8 is a key subunit of Mediator complex, a large multiprotein complex that is a fundamental part of the conserved eukaryotic transcriptional machinery. However, the biological functions of CDK8 in plant abiotic stress responses remain largely unexplored. Here, we demonstrated CDK8 as a critical regulator in the abscisic acid (ABA) signaling and drought response pathways in Arabidopsis. Compared to wild-type, cdk8 mutants showed reduced sensitivity to ABA, impaired stomatal apertures and hypersensitivity to drought stress. Transcriptomic and chromatin immunoprecipitation analysis revealed that CDK8 positively regulates the transcription of several ABA-responsive genes, probably through promoting the recruitment of RNA polymerase II to their promoters. We discovered that both CDK8 and SnRK2.6 interact physically with an ERF/AP2 transcription factor RAP2.6, which can directly bind to the promoters of RD29A and COLD-REGULATED 15A (COR15A) with GCC or DRE elements, thereby promoting their expression. Importantly, we also showed that CDK8 is essential for the ABA-induced expression of RAP2.6 and RAP2.6-mediated upregulation of ABA-responsive genes, indicating that CDK8 could link the SnRK2.6-mediated ABA signaling to RNA polymerase II to promote immediate transcriptional response to ABA and drought signals. Overall, our data provide new insights into the roles of CDK8 in modulating ABA signaling and drought responses.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Quinase 8 Dependente de Ciclina , Fatores de Transcrição , Ácido Abscísico , Arabidopsis/genética , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Quinase 8 Dependente de Ciclina/genética , Secas , Regulação da Expressão Gênica de Plantas , Proteínas Serina-Treonina Quinases/metabolismo , Estresse Fisiológico/genética , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
10.
PLoS Genet ; 13(4): e1006753, 2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-28419088

RESUMO

MicroRNAs (miRNAs) regulate gene expression and play critical roles in growth and development as well as stress responses in eukaryotes. miRNA biogenesis in plants requires a processing complex that consists of the core components DICER-LIKE 1 (DCL1), SERRATE (SE) and HYPONASTIC LEAVES (HYL1). Here we show that inactivation of functionally redundant members of the SnRK2 kinases, which are the core components of abscisic acid (ABA) and osmotic stress signaling pathways, leads to reduction in miRNA accumulation under stress conditions. Further analysis revealed that the steady state level of HYL1 protein in plants under osmotic stress is dependent on the SnRK2 kinases. Additionally, our results suggest that the SnRK2 kinases physically associate with the miRNA processing components SE and HYL1 and can phosphorylate these proteins in vitro. These findings reveal an important role for the SnRK2 kinases in the regulation of miRNA accumulation and establish a mechanism by which ABA and osmotic stress signaling is linked to miRNA biogenesis.


Assuntos
Proteínas de Arabidopsis/biossíntese , Proteínas de Arabidopsis/genética , Proteínas de Ciclo Celular/biossíntese , MicroRNAs/biossíntese , Proteínas Serina-Treonina Quinases/genética , Proteínas de Ligação a RNA/biossíntese , Ribonuclease III/biossíntese , Ácido Abscísico/metabolismo , Arabidopsis/genética , Arabidopsis/crescimento & desenvolvimento , Proteínas de Ciclo Celular/genética , Regulação da Expressão Gênica de Plantas , MicroRNAs/genética , Pressão Osmótica , Fosforilação , Folhas de Planta/genética , Folhas de Planta/crescimento & desenvolvimento , Proteínas Serina-Treonina Quinases/biossíntese , Proteínas de Ligação a RNA/genética , Ribonuclease III/genética , Transdução de Sinais
11.
J Integr Plant Biol ; 62(3): 258-263, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32068336

RESUMO

A recent paper by Kidokoro et al. (2020) in The Plant Cell reported a transgene-dependent transcriptional silencing phenomenon in the dominant ice1-1 Arabidopsis mutant containing the CBF3-LUC reporter, and questioned whether ICE1 may regulate CBF genes and may be involved in plant cold response. Here, we evaluate available evidence supporting the involvement of ICE1 in plant cold response, and provide ChIP-seq data showing ICE1 binding to the promoters of CBF genes and other regulatory genes known to be critical for cold response as well as to the promoters of some COR genes.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Arabidopsis/fisiologia , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Temperatura Baixa , Regulação da Expressão Gênica de Plantas/genética , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/metabolismo , Plantas Geneticamente Modificadas/fisiologia , Regiões Promotoras Genéticas/genética , Transdução de Sinais/genética , Transdução de Sinais/fisiologia , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
12.
New Phytol ; 224(1): 274-290, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31009077

RESUMO

The capability to maintain cell wall integrity is critical for plants to adapt to unfavourable conditions. l-Arabinose (Ara) is a constituent of several cell wall polysaccharides and many cell wall-localised glycoproteins, but so far the contribution of Ara metabolism to abiotic stress tolerance is still poorly understood. Here, we report that mutations in the MUR4 (also known as HSR8) gene, which is required for the biosynthesis of UDP-Arap in Arabidopsis, led to reduced root elongation under high concentrations of NaCl, KCl, NaNO3 , or KNO3 . The short root phenotype of the mur4/hsr8 mutants under high salinity is rescued by exogenous Ara or gum arabic, a commercial product of arabinogalactan proteins (AGPs) from Acacia senegal. Mutation of the MUR4 gene led to abnormal cell-cell adhesion under salt stress. MUR4 forms either a homodimer or heterodimers with its isoforms. Analysis of the higher order mutants of MUR4 with its three paralogues, MURL, DUR, MEE25, reveals that the paralogues of MUR4 also contribute to the biosynthesis of UDP-Ara and are critical for root elongation. Taken together, our work revealed the importance of the Ara metabolism in salt stress tolerance and also provides new insights into the enzymes involved in the UDP-Ara biosynthesis in plants.


Assuntos
Arabidopsis/fisiologia , Arabinose/biossíntese , Tolerância ao Sal/fisiologia , Estresse Fisiológico , Ácido Abscísico/farmacologia , Arabidopsis/efeitos dos fármacos , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Arabinose/farmacologia , Adesão Celular/efeitos dos fármacos , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Mucoproteínas/metabolismo , Mutação/genética , Fenótipo , Proteínas de Plantas/metabolismo , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/crescimento & desenvolvimento , Isoformas de Proteínas/metabolismo , Multimerização Proteica/efeitos dos fármacos , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Cloreto de Sódio/farmacologia , Regulação para Cima/efeitos dos fármacos , Regulação para Cima/genética
13.
PLoS Genet ; 12(11): e1006416, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27812104

RESUMO

The function of miR165/166 in plant growth and development has been extensively studied, however, its roles in abiotic stress responses remain largely unknown. Here, we report that reduction in the expression of miR165/166 conferred a drought and cold resistance phenotype and hypersensitivity to ABA during seed germination and post-germination seedling development. We further show that the ABA hypersensitive phenotype is associated with a changed transcript abundance of ABA-responsive genes and a higher expression level of ABI4, which can be directly regulated by a miR165/166 target. Additionally, we found that reduction in miR165/166 expression leads to elevated ABA levels, which occurs at least partially through the increased expression of BG1, a gene that is directly regulated by a miR165/166 target. Taken together, our results uncover a novel role for miR165/166 in the regulation of ABA and abiotic stress responses and control of ABA homeostasis.


Assuntos
Ácido Abscísico/genética , Arabidopsis/genética , MicroRNAs/genética , Arabidopsis/crescimento & desenvolvimento , Secas , Regulação da Expressão Gênica de Plantas , Germinação/genética , Homeostase/genética , Mutação , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/crescimento & desenvolvimento , Plântula/genética , Plântula/crescimento & desenvolvimento , Sementes/genética , Sementes/crescimento & desenvolvimento , Estresse Fisiológico/genética
14.
Anal Chem ; 90(17): 10263-10270, 2018 09 04.
Artigo em Inglês | MEDLINE | ID: mdl-30103608

RESUMO

Protein phosphorylation is one of the most important and widespread molecular regulatory mechanisms that controls almost all aspects of cellular functions in animals and plants. Here, we introduce a novel chemically functionalized reverse phase phosphoprotein array (RP3A) to capture and measure phosphoproteomes. RP3A uses polyamidoamine (PAMAM) dendrimer immobilized with Ti(IV) ions to functionalize nitrocellulose membrane, facilitating specific chelation of phosphoproteins from complex protein samples on the array. Globular, water-soluble Ti(IV)-dendrimer allows the RP3A surface to be highly accessible to phosphoproteins multidimensionally, and the captured phosphoproteins were subsequently detected using the same validated antibodies as in regular reverse-phase protein arrays. The novel chemical strategy demonstrated superior specificity (1:10 000), high sensitivity (fg level), and good quantitative nature ( R2 = 0.99) for measuring phosphoproteins. We further applied quantitative phosphoproteomics followed by RP3A to validate the phosphorylation status of a panel of phosphoproteins in response to environmental stresses in Arabidopsis.


Assuntos
Proteínas de Arabidopsis/química , Nanoestruturas/química , Fosfoproteínas/química , Polímeros/química , Arabidopsis/química , Cromatografia Líquida , Bases de Dados de Proteínas , Fosforilação , Análise Serial de Proteínas , Espectrometria de Massas em Tandem
15.
Plant Physiol ; 171(4): 2744-59, 2016 08.
Artigo em Inglês | MEDLINE | ID: mdl-27252305

RESUMO

The three tandemly arranged CBF genes, CBF1, CBF2, and CBF3, are involved in cold acclimation. Due to the lack of stable loss-of-function Arabidopsis (Arabidopsis thaliana) mutants deficient in all three CBF genes, it is still unclear whether the CBF genes are essential for freezing tolerance and whether they may have other functions besides cold acclimation. In this study, we used the CRISPR/Cas9 system to generate cbf single, double, and triple mutants. Compared to the wild type, the cbf triple mutants are extremely sensitive to freezing after cold acclimation, demonstrating that the three CBF genes are essential for cold acclimation. Our results show that the three CBF genes also contribute to basal freezing tolerance. Unexpectedly, we found that the cbf triple mutants are defective in seedling development and salt stress tolerance. Transcript profiling revealed that the CBF genes regulate 414 cold-responsive (COR) genes, of which 346 are CBF-activated genes and 68 are CBF-repressed genes. The analysis suggested that CBF proteins are extensively involved in the regulation of carbohydrate and lipid metabolism, cell wall modification, and gene transcription. Interestingly, like the triple mutants, cbf2 cbf3 double mutants are more sensitive to freezing after cold acclimation compared to the wild type, but cbf1 cbf3 double mutants are more resistant, suggesting that CBF2 is more important than CBF1 and CBF3 in cold acclimation-dependent freezing tolerance. Our results not only demonstrate that the three CBF genes together are required for cold acclimation and freezing tolerance, but also reveal that they are important for salt tolerance and seedling development.


Assuntos
Aclimatação/genética , Proteínas de Arabidopsis/metabolismo , Arabidopsis/genética , Arabidopsis/fisiologia , Temperatura Baixa , Mutação/genética , Fatores de Transcrição/metabolismo , Aclimatação/efeitos dos fármacos , Arabidopsis/efeitos dos fármacos , Arabidopsis/crescimento & desenvolvimento , Proteínas de Arabidopsis/genética , Congelamento , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Genes de Plantas , Germinação/efeitos dos fármacos , Germinação/genética , Pressão Osmótica/efeitos dos fármacos , Fenótipo , Sementes/efeitos dos fármacos , Sementes/genética , Sementes/crescimento & desenvolvimento , Cloreto de Sódio/farmacologia , Estresse Fisiológico/efeitos dos fármacos , Fatores de Transcrição/genética
16.
Plant Cell Environ ; 40(1): 56-68, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-27577186

RESUMO

In yeast, the interaction of General Control Non-derepressible 1 (GCN1) with GCN2 enables GCN2 to phosphorylate eIF2α (the alpha subunit of eukaryotic translation initiation factor 2) under a variety of stresses. Here, we cloned AtGCN1, an Arabidopsis homologue of GCN1. We show that AtGCN1 directly interacts with GCN2 and is essential for the phosphorylation of eIF2α under salicylic acid (SA), ultraviolet (UV), cold stress and amino acid deprivation conditions. Two mutant alleles, atgcn1-1 and atgcn1-2, which are defective in the phosphorylation of eIF2α, showed increased sensitivity to cold stress, compared with the wild type. Ribosome-bound RNA profiles showed that the translational state of mRNA was higher in atgcn1-1 than in the wild type. Our result also showed that cold treatment reduced the tendency of the tor mutant seedlings to produce purple hypocotyls. In addition, the kinase activity of TOR was transiently inhibited when plants were exposed to cold stress, suggesting that the inhibition of TOR is another pathway important for plants to respond to cold stress. In conclusion, our results indicate that the AtGCN1-mediated phosphorylation of eIF2α, which is required for inhibiting the initiation of protein translation, is essential for cold tolerance in Arabidopsis.


Assuntos
Adaptação Fisiológica , Proteínas de Arabidopsis/metabolismo , Arabidopsis/fisiologia , Temperatura Baixa , Biossíntese de Proteínas , Adaptação Fisiológica/efeitos dos fármacos , Arabidopsis/efeitos dos fármacos , Arabidopsis/genética , Sequência de Bases , Clonagem Molecular , Fator de Iniciação 2 em Eucariotos/metabolismo , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Herbicidas/toxicidade , Modelos Biológicos , Fosforilação/efeitos dos fármacos , Ligação Proteica/efeitos dos fármacos , Biossíntese de Proteínas/efeitos dos fármacos , Proteínas Quinases/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Ribossomos/efeitos dos fármacos , Ribossomos/metabolismo , Estresse Fisiológico/efeitos dos fármacos , Sulfonamidas/toxicidade , Triazinas/toxicidade
17.
PLoS Genet ; 10(5): e1004389, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24830651

RESUMO

Mitogen-activated protein (MAP) kinase signaling cascades play important roles in the regulation of plant defense. The Raf-like MAP kinase kinase kinase (MAPKKK) EDR1 negatively regulates plant defense responses and cell death. However, how EDR1 functions, and whether it affects the regulation of MAPK cascades, are not well understood. Here, we showed that EDR1 negatively regulates the MKK4/MKK5-MPK3/MPK6 kinase cascade in Arabidopsis. We found that edr1 mutants have highly activated MPK3/MPK6 kinase activity and higher levels of MPK3/MPK6 proteins than wild type. EDR1 physically interacts with MKK4 and MKK5, and this interaction requires the N-terminal domain of EDR1. EDR1 also negatively affects MKK4/MKK5 protein levels. In addition, the mpk3, mkk4 and mkk5 mutations suppress edr1-mediated resistance, and over-expression of MKK4 or MKK5 causes edr1-like resistance and mildew-induced cell death. Taken together, our data indicate that EDR1 physically associates with MKK4/MKK5 and negatively regulates the MAPK cascade to fine-tune plant innate immunity.


Assuntos
Proteínas de Arabidopsis/metabolismo , Quinases de Proteína Quinase Ativadas por Mitógeno/metabolismo , Imunidade Vegetal/genética , Arabidopsis , Proteínas de Arabidopsis/imunologia , Regulação da Expressão Gênica de Plantas , Sistema de Sinalização das MAP Quinases/genética , Quinases de Proteína Quinase Ativadas por Mitógeno/imunologia , Fosforilação , Doenças das Plantas/genética , Doenças das Plantas/imunologia , Plantas Geneticamente Modificadas/genética
18.
BMC Genomics ; 15: 191, 2014 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-24625133

RESUMO

BACKGROUND: Genome comparisons between closely related species often show non-conserved regions across chromosomes. Some of them are located in specific regions of chromosomes and some are even confined to one or more entire chromosomes. The origin and biological relevance of these non-conserved regions are still largely unknown. Here we used the genome of Fusarium graminearum to elucidate the significance of non-conserved regions. RESULTS: The genome of F. graminearum harbours thirteen non-conserved regions dispersed over all of the four chromosomes. Using RNA-Seq data from the mycelium of F. graminearum, we found weakly expressed regions on all of the four chromosomes that exactly matched with non-conserved regions. Comparison of gene expression between two different developmental stages (conidia and mycelium) showed that the expression of genes in conserved regions is stable, while gene expression in non-conserved regions is much more influenced by developmental stage. In addition, genes involved in the production of secondary metabolites and secreted proteins are enriched in non-conserved regions, suggesting that these regions could also be important for adaptations to new environments, including adaptation to new hosts. Finally, we found evidence that non-conserved regions are generated by sequestration of genes from multiple locations. Gene relocations may lead to clustering of genes with similar expression patterns or similar biological functions, which was clearly exemplified by the PKS2 gene cluster. CONCLUSIONS: Our results showed that chromosomes can be functionally divided into conserved and non-conserved regions, and both could have specific and distinct roles in genome evolution and regulation of gene expression.


Assuntos
Cromossomos Fúngicos , Fusarium/genética , Regulação Fúngica da Expressão Gênica , Genes Fúngicos , Evolução Molecular , Fusarium/metabolismo , Perfilação da Expressão Gênica , Regulação da Expressão Gênica no Desenvolvimento , Família Multigênica , Análise de Sequência de RNA , Sintenia
19.
Cell Rep ; 43(5): 114179, 2024 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-38691455

RESUMO

Plant pathogens manipulate host development, facilitating colonization and proliferation. Ralstonia solanacearum is a soil-borne bacterial pathogen that penetrates roots and colonizes plants through the vascular system, causing wilting and death. Here, we find that RipAC, an effector protein from R. solanacearum, alters root development in Arabidopsis, promoting the formation of lateral roots and root hairs. RipAC interacts with CELLULOSE SYNTHASE (CESA)-INTERACTIVE PROTEIN 1 (CSI1), which regulates the activity of CESA complexes at the plasma membrane. RipAC disrupts CESA-CSI1 interaction, leading to a reduction in cellulose content, root developmental alterations, and a promotion of bacterial pathogenicity. We find that CSI1 also associates with the receptor kinase FERONIA, forming a complex that negatively regulates immunity in roots; this interaction, however, is not affected by RipAC. Our work reveals a bacterial virulence strategy that selectively affects the activities of a host target, promoting anatomical alterations that facilitate infection without causing activation of immunity.


Assuntos
Arabidopsis , Parede Celular , Doenças das Plantas , Raízes de Plantas , Ralstonia solanacearum , Raízes de Plantas/microbiologia , Raízes de Plantas/crescimento & desenvolvimento , Arabidopsis/microbiologia , Arabidopsis/crescimento & desenvolvimento , Arabidopsis/metabolismo , Ralstonia solanacearum/patogenicidade , Ralstonia solanacearum/crescimento & desenvolvimento , Ralstonia solanacearum/metabolismo , Doenças das Plantas/microbiologia , Parede Celular/metabolismo , Proteínas de Arabidopsis/metabolismo , Proteínas de Bactérias/metabolismo , Microbiologia do Solo , Glucosiltransferases/metabolismo
20.
BMC Genomics ; 14: 21, 2013 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-23324402

RESUMO

BACKGROUND: The genome of Fusarium graminearum has been sequenced and annotated previously, but correct gene annotation remains a challenge. In addition, posttranscriptional regulations, such as alternative splicing and RNA editing, are poorly understood in F. graminearum. Here we took advantage of RNA-Seq to improve gene annotations and to identify alternative splicing and RNA editing in F. graminearum. RESULTS: We identified and revised 655 incorrectly predicted gene models, including revisions of intron predictions, intron splice sites and prediction of novel introns. 231 genes were identified with two or more alternative splice variants, mostly due to intron retention. Interestingly, the expression ratios between different transcript isoforms appeared to be developmentally regulated. Surprisingly, no RNA editing was identified in F. graminearum. Moreover, 2459 novel transcriptionally active regions (nTARs) were identified and our analysis indicates that many of these could be missed genes. Finally, we identified the 5' UTR and/or 3' UTR sequences of 7666 genes. A number of representative novel gene models and alternatively spliced genes were validated by reverse transcription polymerase chain reaction and sequencing of the generated amplicons. CONCLUSIONS: We have developed novel and efficient strategies to identify alternatively spliced genes and incorrect gene models based on RNA-Seq data. Our study identified hundreds of alternatively spliced genes in F. graminearum and for the first time indicated that alternative splicing is developmentally regulated in filamentous fungi. In addition, hundreds of incorrect predicted gene models were identified and revised and thousands of nTARs were discovered in our study, which will be helpful for the future genomic and transcriptomic studies in F. graminearum.


Assuntos
Processamento Alternativo/genética , Fusarium/genética , Modelos Genéticos , RNA Fúngico/genética , Análise de Sequência de RNA , Sequência de Bases , Fusarium/crescimento & desenvolvimento , Genes Fúngicos/genética , Dados de Sequência Molecular , Controle de Qualidade , Edição de RNA/genética , Sítios de Splice de RNA/genética , Transcrição Gênica/genética , Regiões não Traduzidas/genética
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