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1.
EMBO J ; 42(19): e112999, 2023 Oct 04.
Artigo em Inglês | MEDLINE | ID: mdl-37622245

RESUMO

Cold stress is a major abiotic stress that adversely affects plant growth and crop productivity. The C-REPEAT BINDING FACTOR/DRE BINDING FACTOR 1 (CBF/DREB1) transcriptional regulatory cascade plays a key role in regulating cold acclimation and freezing tolerance in Arabidopsis (Arabidopsis thaliana). Here, we show that max (more axillary growth) mutants deficient in strigolactone biosynthesis and signaling display hypersensitivity to freezing stress. Exogenous application of GR245DS , a strigolactone analog, enhances freezing tolerance in wild-type plants and strigolactone-deficient mutants and promotes the cold-induced expression of CBF genes. Biochemical analysis showed that the transcription factor WRKY41 serves as a substrate for the F-box E3 ligase MAX2. WRKY41 directly binds to the W-box in the promoters of CBF genes and represses their expression, negatively regulating cold acclimation and freezing tolerance. MAX2 ubiquitinates WRKY41, thus marking it for cold-induced degradation and thereby alleviating the repression of CBF expression. In addition, SL-mediated degradation of SMXLs also contributes to enhanced plant freezing tolerance by promoting anthocyanin biosynthesis. Taken together, our study reveals the molecular mechanism underlying strigolactones promote the cold stress response in Arabidopsis.

2.
Plant Cell ; 2024 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-38875155

RESUMO

Plants respond to cold stress at multiple levels, including increasing cytosolic calcium (Ca2+) influx and triggering the expression of cold-responsive genes. Here we show that the Ca2+-permeable channel CYCLIC NUCLEOTIDE GATED CHANNEL20 (CNGC20) positively regulates freezing tolerance in Arabidopsis (Arabidopsis thaliana) by mediating cold-induced Ca2+ influx. Moreover, we demonstrate that the leucine-rich repeat receptor-like kinase PLANT PEPTIDE CONTAINING SULFATED TYROSINE1 RECEPTOR (PSY1R) is activated by cold, phosphorylating and enhancing the activity of CNGC20. The psy1r mutant exhibited decreased cold-evoked Ca2+ influx and freezing tolerance. Conversely, COLD-RESPONSIVE PROTEIN KINASE1 (CRPK1), a protein kinase that negatively regulates cold signaling, phosphorylates and facilitates the degradation of CNGC20 under prolonged periods of cold treatment, thereby attenuating freezing tolerance. This study thus identifies PSY1R and CRPK1 kinases that regulate CNGC20 activity and stability, respectively, thereby antagonistically modulating freezing tolerance in plants.

3.
Plant Cell ; 35(9): 3585-3603, 2023 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-37279565

RESUMO

Ubiquitination modulates protein turnover or activity depending on the number and location of attached ubiquitin (Ub) moieties. Proteins marked by a lysine 48 (K48)-linked polyubiquitin chain are usually targeted to the 26S proteasome for degradation; however, other polyubiquitin chains, such as those attached to K63, usually regulate other protein properties. Here, we show that 2 PLANT U-BOX E3 ligases, PUB25 and PUB26, facilitate both K48- and K63-linked ubiquitination of the transcriptional regulator INDUCER OF C-REPEAT BINDING FACTOR (CBF) EXPRESSION1 (ICE1) during different periods of cold stress in Arabidopsis (Arabidopsis thaliana), thus dynamically modulating ICE1 stability. Moreover, PUB25 and PUB26 attach both K48- and K63-linked Ub chains to MYB15 in response to cold stress. However, the ubiquitination patterns of ICE1 and MYB15 mediated by PUB25 and PUB26 differ, thus modulating their protein stability and abundance during different stages of cold stress. Furthermore, ICE1 interacts with and inhibits the DNA-binding activity of MYB15, resulting in an upregulation of CBF expression. This study unravels a mechanism by which PUB25 and PUB26 add different polyubiquitin chains to ICE1 and MYB15 to modulate their stability, thereby regulating the timing and degree of cold stress responses in plants.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/metabolismo , Proteínas de Arabidopsis/metabolismo , Resposta ao Choque Frio , Poliubiquitina/metabolismo , Fatores de Transcrição/metabolismo , Ubiquitinação , Ubiquitina/metabolismo
4.
EMBO J ; 40(2): e104559, 2021 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-33372703

RESUMO

The transient elevation of cytosolic free calcium concentration ([Ca2+ ]cyt ) induced by cold stress is a well-established phenomenon; however, the underlying mechanism remains elusive. Here, we report that the Ca2+ -permeable transporter ANNEXIN1 (AtANN1) mediates cold-triggered Ca2+ influx and freezing tolerance in Arabidopsis thaliana. The loss of function of AtANN1 substantially impaired freezing tolerance, reducing the cold-induced [Ca2+ ]cyt increase and upregulation of the cold-responsive CBF and COR genes. Further analysis showed that the OST1/SnRK2.6 kinase interacted with and phosphorylated AtANN1, which consequently enhanced its Ca2+ transport activity, thereby potentiating Ca2+ signaling. Consistent with these results and freezing sensitivity of ost1 mutants, the cold-induced [Ca2+ ]cyt elevation in the ost1-3 mutant was reduced. Genetic analysis indicated that AtANN1 acts downstream of OST1 in responses to cold stress. Our data thus uncover a cascade linking OST1-AtANN1 to cold-induced Ca2+ signal generation, which activates the cold response and consequently enhances freezing tolerance in Arabidopsis.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Sinalização do Cálcio/fisiologia , Cálcio/metabolismo , Resposta ao Choque Frio/fisiologia , Membrana Celular/metabolismo , Temperatura Baixa , Congelamento , Regulação da Expressão Gênica de Plantas/fisiologia , Proteínas Quinases/metabolismo , Fatores de Transcrição/metabolismo
5.
Plant Cell ; 34(8): 2833-2851, 2022 07 30.
Artigo em Inglês | MEDLINE | ID: mdl-35543494

RESUMO

Maize (Zea mays) originated in tropical areas and is thus susceptible to low temperatures, which pose a major threat to maize production. Our understanding of the molecular basis of cold tolerance in maize is limited. Here, we identified bZIP68, a basic leucine zipper (bZIP) transcription factor, as a negative regulator of cold tolerance in maize. Transcriptome analysis revealed that bZIP68 represses the cold-induced expression of DREB1 transcription factor genes. The stability and transcriptional activity of bZIP68 are controlled by its phosphorylation at the conserved Ser250 residue under cold stress. Furthermore, we demonstrated that the bZIP68 locus was a target of selection during early domestication. A 358-bp insertion/deletion (Indel-972) polymorphism in the bZIP68 promoter has a significant effect on the differential expression of bZIP68 between maize and its wild ancestor teosinte. This study thus uncovers an evolutionary cis-regulatory variant that could be used to improve cold tolerance in maize.


Assuntos
Fatores de Transcrição , Zea mays , Fatores de Transcrição de Zíper de Leucina Básica/genética , Fatores de Transcrição de Zíper de Leucina Básica/metabolismo , Domesticação , Regiões Promotoras Genéticas/genética , Fatores de Transcrição/metabolismo , Zea mays/metabolismo
6.
Plant Cell ; 34(7): 2708-2729, 2022 07 04.
Artigo em Inglês | MEDLINE | ID: mdl-35404404

RESUMO

Stomatal opening is largely promoted by light-activated plasma membrane-localized proton ATPases (PM H+-ATPases), while their closure is mainly modulated by abscisic acid (ABA) signaling during drought stress. It is unknown whether PM H+-ATPases participate in ABA-induced stomatal closure. We established that BRI1-ASSOCIATED RECEPTOR KINASE 1 (BAK1) interacts with, phosphorylates and activates the major PM Arabidopsis H+-ATPase isoform 2 (AHA2). Detached leaves from aha2-6 single mutant Arabidopsis thaliana plants lost as much water as bak1-4 single and aha2-6 bak1-4 double mutants, with all three mutants losing more water than the wild-type (Columbia-0 [Col-0]). In agreement with these observations, aha2-6, bak1-4, and aha2-6 bak1-4 mutants were less sensitive to ABA-induced stomatal closure than Col-0, whereas the aha2-6 mutation did not affect ABA-inhibited stomatal opening under light conditions. ABA-activated BAK1 phosphorylated AHA2 at Ser-944 in its C-terminus and activated AHA2, leading to rapid H+ efflux, cytoplasmic alkalinization, and reactive oxygen species (ROS) accumulation, to initiate ABA signal transduction and stomatal closure. The phosphorylation-mimicking mutation AHA2S944D driven by its own promoter could largely compensate for the defective phenotypes of water loss, cytoplasmic alkalinization, and ROS accumulation in both aha2-6 and bak1-4 mutants. Our results uncover a crucial role of AHA2 in cytoplasmic alkalinization and ABA-induced stomatal closure during the plant's response to drought stress.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Ácido Abscísico/metabolismo , Ácido Abscísico/farmacologia , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Membrana Celular/metabolismo , Mutação/genética , Fosforilação , Estômatos de Plantas/metabolismo , Proteínas Serina-Treonina Quinases/genética , ATPases Translocadoras de Prótons/genética , ATPases Translocadoras de Prótons/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Água/metabolismo
7.
Mol Cell ; 66(1): 117-128.e5, 2017 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-28344081

RESUMO

In plant cells, changes in fluidity of the plasma membrane may serve as the primary sensor of cold stress; however, the precise mechanism and how the cell transduces and fine-tunes cold signals remain elusive. Here we show that the cold-activated plasma membrane protein cold-responsive protein kinase 1 (CRPK1) phosphorylates 14-3-3 proteins. The phosphorylated 14-3-3 proteins shuttle from the cytosol to the nucleus, where they interact with and destabilize the key cold-responsive C-repeat-binding factor (CBF) proteins. Consistent with this, the crpk1 and 14-3-3κλ mutants show enhanced freezing tolerance, and transgenic plants overexpressing 14-3-3λ show reduced freezing tolerance. Further study shows that CRPK1 is essential for the nuclear translocation of 14-3-3 proteins and for 14-3-3 function in freezing tolerance. Thus, our study reveals that the CRPK1-14-3-3 module transduces the cold signal from the plasma membrane to the nucleus to modulate CBF stability, which ensures a faithfully adjusted response to cold stress of plants.


Assuntos
Proteínas 14-3-3/metabolismo , Proteínas de Arabidopsis/metabolismo , Arabidopsis/enzimologia , Membrana Celular/enzimologia , Núcleo Celular/enzimologia , Temperatura Baixa , Resposta ao Choque Frio , Proteínas Quinases/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Transdução de Sinais , Sensação Térmica , Fatores de Transcrição/metabolismo , Proteínas 14-3-3/genética , Transporte Ativo do Núcleo Celular , Adaptação Fisiológica , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Ativação Enzimática , Genótipo , Fluidez de Membrana , Mutação , Fenótipo , Fosforilação , Plantas Geneticamente Modificadas , Complexo de Endopeptidases do Proteassoma/metabolismo , Proteínas Quinases/genética , Proteínas Serina-Treonina Quinases/genética , Estabilidade Proteica , Proteólise , Fatores de Tempo , Fatores de Transcrição/genética
8.
EMBO J ; 39(13): e103630, 2020 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-32449547

RESUMO

Light and temperature are two core environmental factors that coordinately regulate plant growth and survival throughout their entire life cycle. However, the mechanisms integrating light and temperature signaling pathways in plants remain poorly understood. Here, we report that CBF1, an AP2/ERF-family transcription factor essential for plant cold acclimation, promotes hypocotyl growth under ambient temperatures in Arabidopsis. We show that CBF1 increases the protein abundance of PIF4 and PIF5, two phytochrome-interacting bHLH-family transcription factors that play pivotal roles in modulating plant growth and development, by directly binding to their promoters to induce their gene expression, and by inhibiting their interaction with phyB in the light. Moreover, our data demonstrate that CBF1 promotes PIF4/PIF5 protein accumulation and hypocotyl growth at both 22°C and 17°C, but not at 4°C, with a more prominent role at 17°C than at 22°C. Together, our study reveals that CBF1 integrates light and temperature control of hypocotyl growth by promoting PIF4 and PIF5 protein abundance in the light, thus providing insights into the integration mechanisms of light and temperature signaling pathways in plants.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/crescimento & desenvolvimento , Hipocótilo/crescimento & desenvolvimento , Temperatura , Transativadores/metabolismo , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Hipocótilo/genética , Transativadores/genética
9.
Plant Cell ; 33(11): 3555-3573, 2021 11 04.
Artigo em Inglês | MEDLINE | ID: mdl-34427646

RESUMO

Light and temperature are two key environmental factors that coordinately regulate plant growth and development. Although the mechanisms that integrate signaling mediated by cold and red light have been unraveled, the roles of the blue light photoreceptors cryptochromes in plant responses to cold remain unclear. In this study, we demonstrate that the CRYPTOCHROME2 (CRY2)-COP1-HY5-BBX7/8 module regulates blue light-dependent cold acclimation in Arabidopsis thaliana. We show that phosphorylated forms of CRY2 induced by blue light are stabilized by cold stress and that cold-stabilized CRY2 competes with the transcription factor HY5 to attenuate the HY5-COP1 interaction, thereby allowing HY5 to accumulate at cold temperatures. Furthermore, our data demonstrate that B-BOX DOMAIN PROTEIN7 (BBX7) and BBX8 function as direct HY5 targets that positively regulate freezing tolerance by modulating the expression of a set of cold-responsive genes, which mainly occurs independently of the C-repeat-binding factor pathway. Our study uncovers a mechanistic framework by which CRY2-mediated blue-light signaling enhances freezing tolerance, shedding light on the molecular mechanisms underlying the crosstalk between cold and light signaling pathways in plants.


Assuntos
Aclimatação/genética , Arabidopsis/fisiologia , Temperatura Baixa , Transdução de Sinal Luminoso/genética , Luz , Arabidopsis/genética
10.
Plant Cell ; 33(12): 3675-3699, 2021 12 03.
Artigo em Inglês | MEDLINE | ID: mdl-34469582

RESUMO

Verticillium wilt is a severe plant disease that causes massive losses in multiple crops. Increasing the plant resistance to Verticillium wilt is a critical challenge worldwide. Here, we report that the hemibiotrophic Verticillium dahliae-secreted Asp f2-like protein VDAL causes leaf wilting when applied to cotton leaves in vitro but enhances the resistance to V. dahliae when overexpressed in Arabidopsis or cotton without affecting the plant growth and development. VDAL protein interacts with Arabidopsis E3 ligases plant U-box 25 (PUB25) and PUB26 and is ubiquitinated by PUBs in vitro. However, VDAL is not degraded by PUB25 or PUB26 in planta. Besides, the pub25 pub26 double mutant shows higher resistance to V. dahliae than the wild-type. PUBs interact with the transcription factor MYB6 in a yeast two-hybrid screen. MYB6 promotes plant resistance to Verticillium wilt while PUBs ubiquitinate MYB6 and mediate its degradation. VDAL competes with MYB6 for binding to PUBs, and the role of VDAL in increasing Verticillium wilt resistance depends on MYB6. Taken together, these results suggest that plants evolute a strategy to utilize the invaded effector protein VDAL to resist the V. dahliae infection without causing a hypersensitive response (HR); alternatively, hemibiotrophic pathogens may use some effectors to keep plant cells alive during its infection in order to take nutrients from host cells. This study provides the molecular mechanism for plants increasing disease resistance when overexpressing some effector proteins without inducing HR, and may promote searching for more genes from pathogenic fungi or bacteria to engineer plant disease resistance.


Assuntos
Proteínas de Arabidopsis/genética , Arabidopsis/fisiologia , Ascomicetos/fisiologia , Proteínas Fúngicas/genética , Doenças das Plantas/genética , Ubiquitina-Proteína Ligases/genética , Arabidopsis/genética , Arabidopsis/microbiologia , Proteínas de Arabidopsis/metabolismo , Ascomicetos/genética , Resistência à Doença/genética , Proteínas Fúngicas/metabolismo , Doenças das Plantas/microbiologia , Ubiquitina-Proteína Ligases/metabolismo
11.
J Integr Plant Biol ; 2024 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-38804844

RESUMO

Drought stress has negative effects on crop growth and production. Characterization of transcription factors that regulate the expression of drought-responsive genes is critical for understanding the transcriptional regulatory networks in response to drought, which facilitates the improvement of crop drought tolerance. Here, we identified an Alfin-like (AL) family gene ZmAL14 that negatively regulates drought resistance. Overexpression of ZmAL14 exhibits susceptibility to drought while mutation of ZmAL14 enhances drought resistance. An abscisic acid (ABA)-activated protein kinase ZmSnRK2.2 interacts and phosphorylates ZmAL14 at T38 residue. Knockout of ZmSnRK2.2 gene decreases drought resistance of maize. A dehydration-induced Rho-like small guanosine triphosphatase gene ZmROP8 is directly targeted and repressed by ZmAL14. Phosphorylation of ZmAL14 by ZmSnRK2.2 prevents its binding to the ZmROP8 promoter, thereby releasing the repression of ZmROP8 transcription. Overexpression of ZmROP8 stimulates peroxidase activity and reduces hydrogen peroxide accumulation after drought treatment. Collectively, our study indicates that ZmAL14 is a negative regulator of drought resistance, which can be phosphorylated by ZmSnRK2.2 through the ABA signaling pathway, thus preventing its suppression on ZmROP8 transcription during drought stress response.

12.
J Integr Plant Biol ; 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38751035

RESUMO

Calcium oscillations are induced by different stresses. Calcium-dependent protein kinases (CDPKs/CPKs) are one major group of the plant calcium decoders that are involved in various processes including drought response. Some CPKs are calcium-independent. Here, we identified ZmCPK2 as a negative regulator of drought resistance by screening an overexpression transgenic maize pool. We found that ZmCPK2 does not bind calcium, and its activity is mainly inhibited during short term abscisic acid (ABA) treatment, and dynamically changed in prolonged treatment. Interestingly, ZmCPK2 interacts with and is inhibited by calcium-dependent ZmCPK17, a positive regulator of drought resistance, which is activated by ABA. ZmCPK17 could prevent the nuclear localization of ZmCPK2 through phosphorylation of ZmCPK2T60. ZmCPK2 interacts with and phosphorylates and activates ZmYAB15, a negative transcriptional factor for drought resistance. Our results suggest that drought stress-induced Ca2+ can be decoded directly by ZmCPK17 that inhibits ZmCPK2, thereby promoting plant adaptation to water deficit.

13.
EMBO J ; 38(1)2019 01 03.
Artigo em Inglês | MEDLINE | ID: mdl-30429206

RESUMO

OST1 (open stomata 1) protein kinase plays a central role in regulating freezing tolerance in Arabidopsis; however, the mechanism underlying cold activation of OST1 remains unknown. Here, we report that a plasma membrane-localized clade-E growth-regulating 2 (EGR2) phosphatase interacts with OST1 and inhibits OST1 activity under normal conditions. EGR2 is N-myristoylated by N-myristoyltransferase NMT1 at 22°C, which is important for its interaction with OST1. Moreover, myristoylation of EGR2 is required for its function in plant freezing tolerance. Under cold stress, the interaction of EGR2 and NMT1 is attenuated, leading to the suppression of EGR2 myristoylation in plants. Plant newly synthesized unmyristoylated EGR2 has decreased binding ability to OST1 and also interferes with the EGR2-OST1 interaction under cold stress. Consequently, the EGR2-mediated inhibition of OST1 activity is released. Consistently, mutations of EGRs cause plant tolerance to freezing, whereas overexpression of EGR2 exhibits decreased freezing tolerance. This study thus unravels a molecular mechanism underlying cold activation of OST1 by membrane-localized EGR2 and suggests that a myristoyl switch on EGR2 helps plants to adapt to cold stress.


Assuntos
Aclimatação , Proteínas de Arabidopsis/metabolismo , Proteínas de Arabidopsis/fisiologia , Arabidopsis , Temperatura Baixa/efeitos adversos , Proteínas Quinases/metabolismo , Proteína Fosfatase 2C/fisiologia , Aclimatação/genética , Arabidopsis/enzimologia , Arabidopsis/genética , Arabidopsis/crescimento & desenvolvimento , Arabidopsis/metabolismo , Membrana Celular/metabolismo , Resposta ao Choque Frio/genética , Resposta ao Choque Frio/fisiologia , Ativação Enzimática/genética , Ácidos Graxos Monoinsaturados/metabolismo , Congelamento , Regulação da Expressão Gênica de Plantas , Fosforilação , Plantas Geneticamente Modificadas , Processamento de Proteína Pós-Traducional/genética , Transdução de Sinais
14.
New Phytol ; 237(5): 1728-1744, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36444538

RESUMO

Drought is a major environmental stress that threatens crop production. Therefore, identification of genes involved in drought stress response is of vital importance to decipher the molecular mechanism of stress signal transduction and breed drought tolerance crops, especially for maize. Clade A PP2C phosphatases are core abscisic acid (ABA) signaling components, regulating ABA signal transduction and drought response. However, the roles of other clade PP2Cs in drought resistance remain largely unknown. Here, we discovered a clade F PP2C, ZmPP84, that negatively regulates drought tolerance by screening a transgenic overexpression maize library. Quantitative RT-PCR indicates that the transcription of ZmPP84 is suppressed by drought stress. We identified that ZmMEK1, a member of the MAPKK family, interacts with ZmPP84 by immunoprecipitation and mass spectrometry analysis. Additionally, we found that ZmPP84 can dephosphorylate ZmMEK1 and repress its kinase activity on the downstream substrate kinase ZmSIMK1, while ZmSIMK1 is able to phosphorylate S-type anion channel ZmSLAC1 at S146 and T520 in vitro. Mutations of S146 and T520 to phosphomimetic aspartate could activate ZmSLAC1 currents in Xenopus oocytes. Taken together, our study suggests that ZmPP84 is a negative regulator of drought stress response that inhibits stomatal closure through dephosphorylating ZmMEK1, thereby repressing ZmMEK1-ZmSIMK1 signaling pathway.


Assuntos
Ácido Abscísico , Zea mays , Ácido Abscísico/farmacologia , Ácido Abscísico/metabolismo , Zea mays/genética , Zea mays/metabolismo , Resistência à Seca , Melhoramento Vegetal , Fosfoproteínas Fosfatases/genética , Fosfoproteínas Fosfatases/metabolismo , Secas , Regulação da Expressão Gênica de Plantas , Estresse Fisiológico/genética
15.
New Phytol ; 237(1): 140-159, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36110045

RESUMO

14-3-3s are highly conserved phosphopeptide-binding proteins that play important roles in various developmental and signaling pathways in plants. However, although protein phosphorylation has been proven to be a key mechanism for regulating many pivotal components of the light signaling pathway, the role of 14-3-3 proteins in photomorphogenesis remains largely obscure. PHYTOCHROME-INTERACTING FACTOR3 (PIF3) is an extensively studied transcription factor repressing photomorphogenesis, and it is well-established that upon red (R) light exposure, photo-activated phytochrome B (phyB) interacts with PIF3 and induces its rapid phosphorylation and degradation. PHOTOREGULATORY PROTEIN KINASES (PPKs), a family of nuclear protein kinases, interact with phyB and PIF3 in R light and mediate multisite phosphorylation of PIF3 in vivo. Here, we report that two members of the 14-3-3 protein family, 14-3-3λ and κ, bind to a serine residue in the bHLH domain of PIF3 that can be phosphorylated by PPKs, and act as key positive regulators of R light-induced photomorphogenesis. Moreover, 14-3-3λ and κ preferentially interact with photo-activated phyB and promote the phyB-PIF3-PPK complex formation, thereby facilitating phyB-induced phosphorylation and degradation of PIF3 upon R light exposure. Together, our data demonstrate that 14-3-3λ and κ work in close concert with the phyB-PIF3 module to regulate light signaling in Arabidopsis.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Fitocromo , Fitocromo/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Proteínas 14-3-3/metabolismo , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Luz , Fitocromo B/metabolismo , Arabidopsis/genética , Arabidopsis/metabolismo
16.
Cytokine ; 161: 156078, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36401983

RESUMO

Sepsis-associated encephalopathy (SAE) is a serious and common complication of sepsis. To study the ferroptosis in the pathogenesis of SAE and demonstrate the protection effect of ferroptosis resistance, cognitive function, neurological deficits, blood-brain barrier integrity and neuroinflammation were detected. SAE model was established by cecal ligation and puncture (CLP) in mice and an in vitro model was created by introducing LPS to HT22 cells. Ferroptosis inducer Fe-citrate (Fe) and ferroptosis inhibitor ferrostatin-1 (Fer-1) was post-treated in the models, respectively. SAE caused ferroptosis, as evidenced by an increase in reactive oxygen species (ROS), iron content and malondialdehyde (MDA) and a decrease in glutathione (GSH) level, as well as changes in the expression of ferroptosis-related proteins as acyl-CoA synthetase long-chain family member 4 (ACSL4), glutathione peroxidase 4 (GPX4), and cystine-glutamate antiporter (SLC7A11), and harmed mitochondrial function. In contrast, inhibiting ferroptosis with Fer-1 attenuated ferroptosis. Meanwhile, Fer-1 attenuated neurologic severity score, learning and memory impairment, Fluoro-Jade C (FJC) staining, and decreased Evans Blue (EB) extravasation, microglia activation and TNF-α and IL-1ß production following SAE. The benefit of Fer-1 was diminished by ferroptosis inducer Fe. In addition, Fer-1 up-regulated the nuclear factor erythroid-2-related factor 2 (Nrf2)/ heme oxygenase-1(HO-1) signaling axis both in vivo and in vitro. In conclusion, our study revealed that Fer-1 might inhibit feroptosis in neurons by triggering the Nrf2/OH-1 pathway, thereby providing a therapeutic solution for SAE.


Assuntos
Ferroptose , Encefalopatia Associada a Sepse , Animais , Camundongos , Fator 2 Relacionado a NF-E2/metabolismo , Cicloexilaminas/farmacologia
17.
J Exp Bot ; 74(17): 5394-5404, 2023 09 13.
Artigo em Inglês | MEDLINE | ID: mdl-37326597

RESUMO

Abscisic acid (ABA) is an essential phytohormone for plant responses to complex and variable environmental conditions. The molecular basis of the ABA signaling pathway has been well elucidated. SnRK2.2 and SnRK2.3 are key protein kinases participating in ABA responses, and the regulation of their activity plays an important role in signaling. Previous mass spectroscopy analysis of SnRK2.3 suggested that ubiquitin and homologous proteins may bind directly to the kinase. Ubiquitin typically recruits E3 ubiquitin ligase complexes to target proteins, marking them for degradation by the 26S proteasome. Here, we show that SnRK2.2 and SnRK2.3 interact with ubiquitin but are not covalently attached to the protein, resulting in the suppression of their kinase activity. The binding between SnRK2.2, SnRK2.3, and ubiquitin is weakened under prolonged ABA treatment. Overexpression of ubiquitin positively regulated the growth of seedlings exposed to ABA. Our results thus demonstrate a novel function for ubiquitin, which negatively regulates ABA responses by directly inhibiting SnRK2.2 and SnRK2.3 kinase activity.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/metabolismo , Ácido Abscísico/metabolismo , Proteínas Serina-Treonina Quinases/genética , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Ubiquitina/metabolismo
18.
Plant Cell ; 32(7): 2196-2215, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32371543

RESUMO

Phytochromes are red (R) and far-red (FR) light photoreceptors in plants, and PHYTOCHROME-INTERACTING FACTORS (PIFs) are a group of basic helix-loop-helix family transcription factors that play central roles in repressing photomorphogenesis. Here, we report that MYB30, an R2R3-MYB family transcription factor, acts as a negative regulator of photomorphogenesis in Arabidopsis (Arabidopsis thaliana). We show that MYB30 preferentially interacts with the Pfr (active) forms of the phytochrome A (phyA) and phytochrome B (phyB) holoproteins and that MYB30 levels are induced by phyA and phyB in the light. It was previously shown that phytochromes induce rapid phosphorylation and degradation of PIFs upon R light exposure. Our current data indicate that MYB30 promotes PIF4 and PIF5 protein reaccumulation under prolonged R light irradiation by directly binding to their promoters to induce their expression and by inhibiting the interaction of PIF4 and PIF5 with the Pfr form of phyB. In addition, our data indicate that MYB30 interacts with PIFs and that they act additively to repress photomorphogenesis. In summary, our study demonstrates that MYB30 negatively regulates Arabidopsis photomorphogenic development by acting to promote PIF4 and PIF5 protein accumulation under prolonged R light irradiation, thus providing new insights into the complicated but delicate control of PIFs in the responses of plants to their dynamic light environment.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/crescimento & desenvolvimento , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Fatores de Transcrição/metabolismo , Arabidopsis/fisiologia , Proteínas de Arabidopsis/genética , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Regulação da Expressão Gênica de Plantas , Luz , Fitocromo A/metabolismo , Fitocromo B/metabolismo , Plantas Geneticamente Modificadas , Regiões Promotoras Genéticas , Plântula/fisiologia , Fatores de Transcrição/genética
19.
Plant Cell ; 32(3): 703-721, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31919300

RESUMO

The phytohormone abscisic acid (ABA) and the Polycomb group proteins have key roles in regulating plant growth and development; however, their interplay and underlying mechanisms are not fully understood. Here, we identified an Arabidopsis (Arabidopsis thaliana) nodulin homeobox (AtNDX) protein as a negative regulator in the ABA signaling pathway. AtNDX mutants are hypersensitive to ABA, as measured by inhibition of seed germination and root growth, and the expression of AtNDX is downregulated by ABA. AtNDX interacts with the Polycomb Repressive Complex1 (PRC1) core components AtRING1A and AtRING1B in vitro and in vivo, and together, they negatively regulate the expression levels of some ABA-responsive genes. We identified ABA-INSENSITIVE (ABI4) as a direct target of AtNDX. AtNDX directly binds the downstream region of ABI4 and deleting this region increases the ABA sensitivity of primary root growth. Furthermore, ABI4 mutations rescue the ABA-hypersensitive phenotypes of ndx mutants and ABI4-overexpressing plants are hypersensitive to ABA in primary root growth. Thus, our work reveals the critical functions of AtNDX and PRC1 in some ABA-mediated processes and their regulation of ABI4.


Assuntos
Ácido Abscísico/metabolismo , Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Proteínas de Transporte/metabolismo , Proteínas de Homeodomínio/metabolismo , Proteínas de Membrana/metabolismo , Proteínas de Plantas/metabolismo , Complexo Repressor Polycomb 1/metabolismo , Transdução de Sinais , Ácido Abscísico/farmacologia , Arabidopsis/efeitos dos fármacos , Proteínas de Arabidopsis/genética , Sequência de Bases , Proteínas de Transporte/genética , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Genes de Plantas , Germinação/efeitos dos fármacos , Proteínas de Homeodomínio/genética , Modelos Biológicos , Mutação/genética , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/metabolismo , Complexo Repressor Polycomb 1/genética , Ligação Proteica/efeitos dos fármacos , Plântula/efeitos dos fármacos , Plântula/crescimento & desenvolvimento , Transdução de Sinais/efeitos dos fármacos
20.
Phys Chem Chem Phys ; 25(37): 25435-25441, 2023 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-37706505

RESUMO

Aqueous Zn-ion batteries (AZIBs) have become one of the most promising energy storage devices due to their high safety and low cost. However, the development of stable cathodes with fast kinetics and high energy density is the key to achieving large-scale application of AZIBs. In this work, W-doped VO2 (W-VO2) is developed by a one-step hydrothermal method. Benefiting from the pre-insertion of W6+ and the introduction of the W-O bond, accomplishing an expanded lattice spacing and a stable structure, both improved kinetics and long cycle life are achieved. The W-VO2 delivers a specific capacity of 340.2 mA h g-1 at 0.2 A g-1, an excellent high-rate capability with a discharge capacity of 186.9 mA h g-1 at 10 A g-1, and long-term cycling stability with a capacity retention of 76.5% after 2000 cycles. The electrochemical performance of the W-VO2 has been greatly improved, compared with the pure VO2. The W doping strategy proposed here also presents an encouraging pathway for developing other high-energy and stable cathodes.

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