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1.
Plant Cell ; 36(7): 2587-2606, 2024 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-38536743

RESUMO

Cold stress affects plant immune responses, and this process may involve the salicylic acid (SA) signaling pathway. However, the underlying mechanism by which low-temperature signals coordinate with SA signaling to regulate plant immunity remains unclear. Here, we found that low temperatures enhanced the disease resistance of Arabidopsis thaliana against Pseudomonas syringae pv. tomato DC3000. This process required INDUCER OF CBF EXPRESSION 1 (ICE1), the core transcription factor in cold-signal cascades. ICE1 physically interacted with NONEXPRESSER OF PATHOGENESIS-RELATED GENES 1 (NPR1), the master regulator of the SA signaling pathway. Enrichment of ICE1 on the PATHOGENESIS-RELATED GENE 1 (PR1) promoter and its ability to transcriptionally activate PR1 were enhanced by NPR1. Further analyses revealed that cold stress signals cooperate with SA signals to facilitate plant immunity against pathogen attack in an ICE1-dependent manner. Cold treatment promoted interactions of NPR1 and TGACG-BINDING FACTOR 3 (TGA3) with ICE1 and increased the ability of the ICE1-TGA3 complex to transcriptionally activate PR1. Together, our results characterize a critical role of ICE1 as an indispensable regulatory node linking low-temperature-activated and SA-regulated immunity. Understanding this crucial role of ICE1 in coordinating multiple signals associated with immunity broadens our understanding of plant-pathogen interactions.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Regulação da Expressão Gênica de Plantas , Doenças das Plantas , Imunidade Vegetal , Pseudomonas syringae , Ácido Salicílico , Transdução de Sinais , Ácido Salicílico/metabolismo , Proteínas de Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Arabidopsis/genética , Arabidopsis/imunologia , Arabidopsis/microbiologia , Arabidopsis/metabolismo , Imunidade Vegetal/genética , Pseudomonas syringae/patogenicidade , Pseudomonas syringae/fisiologia , Doenças das Plantas/microbiologia , Doenças das Plantas/imunologia , Doenças das Plantas/genética , Resistência à Doença/genética , Temperatura Baixa , Fatores de Transcrição de Zíper de Leucina Básica/metabolismo , Fatores de Transcrição de Zíper de Leucina Básica/genética , Fatores de Transcrição/metabolismo , Fatores de Transcrição/genética , Regiões Promotoras Genéticas/genética
2.
Plant Cell ; 35(3): 1110-1133, 2023 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-36516412

RESUMO

Abscisic acid (ABA) represses seed germination and postgerminative growth in Arabidopsis thaliana. Auxin and jasmonic acid (JA) stimulate ABA function; however, the possible synergistic effects of auxin and JA on ABA signaling and the underlying molecular mechanisms remain elusive. Here, we show that exogenous auxin works synergistically with JA to enhance the ABA-induced delay of seed germination. Auxin biosynthesis, perception, and signaling are crucial for JA-promoted ABA responses. The auxin-dependent transcription factors AUXIN RESPONSE FACTOR10 (ARF10) and ARF16 interact with JASMONATE ZIM-DOMAIN (JAZ) repressors of JA signaling. ARF10 and ARF16 positively mediate JA-increased ABA responses, and overaccumulation of ARF16 partially restores the hyposensitive phenotype of JAZ-accumulating plants defective in JA signaling in response to combined ABA and JA treatment. Furthermore, ARF10 and ARF16 physically associate with ABSCISIC ACID INSENSITIVE5 (ABI5), a critical regulator of ABA signaling, and the ability of ARF16 to stimulate JA-mediated ABA responses is mainly dependent on ABI5. ARF10 and ARF16 activate the transcriptional function of ABI5, whereas JAZ repressors antagonize their effects. Collectively, our results demonstrate that auxin contributes to the synergetic modulation of JA on ABA signaling, and explain the mechanism by which ARF10/16 coordinate with JAZ and ABI5 to integrate the auxin, JA, and ABA signaling pathways.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/metabolismo , Ácido Abscísico/farmacologia , Ácido Abscísico/metabolismo , Ácidos Indolacéticos/metabolismo , Germinação , Proteínas de Arabidopsis/metabolismo , Sementes/genética , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
3.
Plant Cell ; 35(2): 852-873, 2023 02 20.
Artigo em Inglês | MEDLINE | ID: mdl-36427252

RESUMO

CONSTANS (CO) is a master flowering-time regulator that integrates photoperiodic and circadian signals in Arabidopsis thaliana. CO is expressed in multiple tissues, including young leaves and seedling roots, but little is known about the roles and underlying mechanisms of CO in mediating physiological responses other than flowering. Here, we show that CO expression is responsive to jasmonate. CO negatively modulated jasmonate-imposed root-growth inhibition and anthocyanin accumulation. Seedlings from co mutants were more sensitive to jasmonate, whereas overexpression of CO resulted in plants with reduced sensitivity to jasmonate. Moreover, CO mediated the diurnal gating of several jasmonate-responsive genes under long-day conditions. We demonstrate that CO interacts with JASMONATE ZIM-DOMAIN (JAZ) repressors of jasmonate signaling. Genetic analyses indicated that CO functions in a CORONATINE INSENSITIVE1 (COI1)-dependent manner to modulate jasmonate responses. Furthermore, CO physically associated with the basic helix-loop-helix (bHLH) subgroup IIId transcription factors bHLH3 and bHLH17. CO acted cooperatively with bHLH17 in suppressing jasmonate signaling, but JAZ proteins interfered with their transcriptional functions and physical interaction. Collectively, our results reveal the crucial regulatory effects of CO on mediating jasmonate responses and explain the mechanism by which CO works together with JAZ and bHLH subgroup IIId factors to fine-tune jasmonate signaling.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/metabolismo , Plântula/genética , Plântula/metabolismo , Proteínas de Arabidopsis/metabolismo , Proteínas Repressoras/genética , Proteínas Repressoras/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Ciclopentanos/farmacologia , Ciclopentanos/metabolismo , Oxilipinas/farmacologia , Oxilipinas/metabolismo , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Regulação da Expressão Gênica de Plantas/genética
4.
Plant Cell ; 35(6): 2132-2156, 2023 05 29.
Artigo em Inglês | MEDLINE | ID: mdl-36856677

RESUMO

Phosphorus (P) is a macronutrient necessary for plant growth and development. Inorganic phosphate (Pi) deficiency modulates the signaling pathway of the phytohormone jasmonate in Arabidopsis thaliana, but the underlying molecular mechanism currently remains elusive. Here, we confirmed that jasmonate signaling was enhanced under low Pi conditions, and the CORONATINE INSENSITIVE1 (COI1)-mediated pathway is critical for this process. A mechanistic investigation revealed that several JASMONATE ZIM-DOMAIN (JAZ) repressors physically interacted with the Pi signaling-related core transcription factors PHOSPHATE STARVATION RESPONSE1 (PHR1), PHR1-LIKE2 (PHL2), and PHL3. Phenotypic analyses showed that PHR1 and its homologs positively regulated jasmonate-induced anthocyanin accumulation and root growth inhibition. PHR1 stimulated the expression of several jasmonate-responsive genes, whereas JAZ proteins interfered with its transcriptional function. Furthermore, PHR1 physically associated with the basic helix-loop-helix (bHLH) transcription factors MYC2, MYC3, and MYC4. Genetic analyses and biochemical assays indicated that PHR1 and MYC2 synergistically increased the transcription of downstream jasmonate-responsive genes and enhanced the responses to jasmonate. Collectively, our study reveals the crucial regulatory roles of PHR1 in modulating jasmonate responses and provides a mechanistic understanding of how PHR1 functions together with JAZ and MYC2 to maintain the appropriate level of jasmonate signaling under conditions of Pi deficiency.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/metabolismo , Proteínas de Arabidopsis/metabolismo , Fosfatos/metabolismo , Proteínas Repressoras/genética , Proteínas Repressoras/metabolismo , Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos/genética , Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo
5.
Plant Physiol ; 193(2): 1675-1694, 2023 09 22.
Artigo em Inglês | MEDLINE | ID: mdl-37379562

RESUMO

CONSTANS (CO) is a critical regulator of flowering that combines photoperiodic and circadian signals in Arabidopsis (Arabidopsis thaliana). CO is expressed in multiple tissues, including seedling roots and young leaves. However, the roles and underlying mechanisms of CO in modulating physiological processes outside of flowering remain obscure. Here, we show that the expression of CO responds to salinity treatment. CO negatively mediated salinity tolerance under long-day (LD) conditions. Seedlings from co-mutants were more tolerant to salinity stress, whereas overexpression of CO resulted in plants with reduced tolerance to salinity stress. Further genetic analyses revealed the negative involvement of GIGANTEA (GI) in salinity tolerance requires a functional CO. Mechanistic analysis demonstrated that CO physically interacts with 4 critical basic leucine zipper (bZIP) transcription factors; ABSCISIC ACID-RESPONSIVE ELEMENT BINDING FACTOR1 (ABF1), ABF2, ABF3, and ABF4. Disrupting these ABFs made plants hypersensitive to salinity stress, demonstrating that ABFs enhance salinity tolerance. Moreover, ABF mutations largely rescued the salinity-tolerant phenotype of co-mutants. CO suppresses the expression of several salinity-responsive genes and influences the transcriptional regulation function of ABF3. Collectively, our results show that the LD-induced CO works antagonistically with ABFs to modulate salinity responses, thus revealing how CO negatively regulates plant adaptation to salinity stress.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Ácido Abscísico/metabolismo , Fatores de Transcrição de Zíper de Leucina Básica/genética , Arabidopsis/metabolismo , Plântula/genética , Estresse Salino/genética , Regulação da Expressão Gênica de Plantas , Estresse Fisiológico/genética , Plantas Geneticamente Modificadas/metabolismo , Proteínas de Ligação a DNA/metabolismo
6.
Plant Physiol ; 191(4): 2519-2533, 2023 04 03.
Artigo em Inglês | MEDLINE | ID: mdl-36715300

RESUMO

ABSCISIC ACID-INSENSITIVE3 (ABI3) and ABI5 are 2 crucial transcription factors in abscisic acid (ABA) signaling, and their homeostasis at the protein level plays a decisive role in seed germination and subsequent seedling growth. Here, we found that PLANT U-BOX 8 (PUB8), a U-box E3 ubiquitin ligase, physically interacts with ABI3 and ABI5 and negatively regulates ABA responses during early Arabidopsis (Arabidopsis thaliana) seedling growth. Loss-of-function pub8 mutants were hypersensitive to ABA-inhibited cotyledon greening, while lines overexpressing PUB8 with low levels of ABI5 protein abundance were insensitive to ABA. Genetic analyses showed that ABI3 and ABI5 were required for the ABA-sensitive phenotype of pub8, indicating that PUB8 functions upstream of ABI3 and ABI5 to regulate ABA responses. Biochemical analyses showed that PUB8 can associate with ABI3 and ABI5 for degradation through the ubiquitin-mediated 26S proteasome pathway. Correspondingly, loss-of-function of PUB8 led to enhanced ABI3 and ABI5 stability, while overexpression of PUB8 impaired accumulation of ABI3 and ABI5 in planta. Further phenotypic analysis indicated that PUB8 compromised the function of ABI5 during early seedling growth. Taken together, our results reveal the regulatory role of PUB8 in modulating the early seedling growth by controlling the homeostasis of ABI3 and ABI5.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Ácido Abscísico/farmacologia , Ácido Abscísico/metabolismo , Plântula/metabolismo , Proteínas de Arabidopsis/metabolismo , Ubiquitina-Proteína Ligases/genética , Ubiquitina-Proteína Ligases/metabolismo , Fatores de Transcrição de Zíper de Leucina Básica/genética , Fatores de Transcrição de Zíper de Leucina Básica/metabolismo , Germinação/genética , Transdução de Sinais , Arabidopsis/metabolismo , Regulação da Expressão Gênica de Plantas , Sementes/genética
7.
Plant Cell ; 33(9): 3022-3041, 2021 09 24.
Artigo em Inglês | MEDLINE | ID: mdl-34152411

RESUMO

Seed germination and postgerminative growth require the precise coordination of multiple intrinsic and environmental signals. The phytohormone abscisic acid (ABA) suppresses these processes in Arabidopsis thaliana and the circadian clock contributes to the regulation of ABA signaling. However, the molecular mechanism underlying circadian clock-mediated ABA signaling remains largely unknown. Here, we found that the core circadian clock proteins PSEUDO-RESPONSE REGULATOR5 (PRR5) and PRR7 physically associate with ABSCISIC ACID-INSENSITIVE5 (ABI5), a crucial transcription factor of ABA signaling. PRR5 and PRR7 positively modulate ABA signaling redundantly during seed germination. Disrupting PRR5 and PRR7 simultaneously rendered germinating seeds hyposensitive to ABA, whereas the overexpression of PRR5 enhanced ABA signaling to inhibit seed germination. Consistent with this, the expression of several ABA-responsive genes is upregulated by PRR proteins. Genetic analysis demonstrated that PRR5 promotes ABA signaling mainly dependently on ABI5. Further mechanistic investigation revealed that PRR5 stimulates the transcriptional function of ABI5 without affecting its stability. Collectively, our results indicate that these PRR proteins function synergistically with ABI5 to activate ABA responses during seed germination, thus providing a mechanistic understanding of how ABA signaling and the circadian clock are directly integrated through a transcriptional complex involving ABI5 and central circadian clock components.


Assuntos
Ácido Abscísico/metabolismo , Proteínas de Arabidopsis/genética , Arabidopsis/fisiologia , Fatores de Transcrição de Zíper de Leucina Básica/genética , Germinação/genética , Proteínas Repressoras/genética , Fatores de Transcrição/genética , Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Fatores de Transcrição de Zíper de Leucina Básica/metabolismo , Proteínas Repressoras/metabolismo , Sementes/crescimento & desenvolvimento , Transdução de Sinais , Fatores de Transcrição/metabolismo
8.
Molecules ; 29(16)2024 Aug 13.
Artigo em Inglês | MEDLINE | ID: mdl-39202916

RESUMO

The diselenide bond has attracted intense interest for drug delivery systems (DDSs) for tumor chemotherapy, owing to it possessing higher redox sensitivity than the disulfide one. Various redox-responsive diselenide-containing carriers have been developed for chemotherapeutics delivery. However, the premature drug leakage from these DDSs was significant enough to cause toxic side effects on normal cells. Here, a pH/redox co-triggered degradable polyprodrug was designed as a drug self-delivery system (DSDS) by incorporating drug molecules as structural units in the polymer main chains, using a facile one-pot two-step approach. The proposed PDOX could only degrade and release drugs by breaking both the neighboring acid-labile acylhydrazone and the redox-cleavable diselenide conjugations in the drug's structural units, triggered by the higher acidity and glutathione (GSH) or reactive oxygen species (ROS) levels in the tumor cells. Therefore, a slow solubility-controlled drug release was achieved for tumor-specific chemotherapy, indicating promising potential as a safe and efficient long-acting DSDS for future tumor treatment.


Assuntos
Antineoplásicos , Oxirredução , Pró-Fármacos , Concentração de Íons de Hidrogênio , Humanos , Pró-Fármacos/química , Pró-Fármacos/farmacologia , Antineoplásicos/química , Antineoplásicos/farmacologia , Liberação Controlada de Fármacos , Espécies Reativas de Oxigênio/metabolismo , Sistemas de Liberação de Medicamentos , Portadores de Fármacos/química , Linhagem Celular Tumoral , Neoplasias/tratamento farmacológico , Neoplasias/metabolismo , Polímeros/química , Glutationa/química , Glutationa/metabolismo , Doxorrubicina/química , Doxorrubicina/farmacologia , Doxorrubicina/administração & dosagem
9.
Molecules ; 29(8)2024 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-38675530

RESUMO

The diselenide bond has attracted intense interest in redox-responsive drug delivery systems (DDSs) in tumor chemotherapy, due to its higher sensitivity than the most investigated bond, namely the disulfide bond. Here, a diselenide-bridged doxorubicin dimeric prodrug (D-DOXSeSe) was designed by coupling two doxorubicin molecules with a diselenodiacetic acid (DSeDAA) molecule via α-amidation, as a redox-triggered drug self-delivery system (DSDS) for tumor-specific chemotherapy. The drug release profiles indicated that the D-DOXSeSe could be cleaved to release the derivatives selenol (DOX-SeH) and seleninic acid (DOX-SeOOH) with the triggering of high GSH and H2O2, respectively, indicating the double-edged sword effect of the lower electronegativity of the selenide atom. The resultant solubility-controlled slow drug release performance makes it a promising candidate as a long-acting DSDS in future tumor chemotherapy. Moreover, the interaction between the conjugations in the design of self-immolation traceless linkers was also proposed for the first time as another key factor for a desired precise tumor-specific chemotherapy, besides the conjugations themselves.


Assuntos
Ácidos Carboxílicos , Doxorrubicina , Liberação Controlada de Fármacos , Oxirredução , Pró-Fármacos , Pró-Fármacos/química , Pró-Fármacos/síntese química , Pró-Fármacos/farmacologia , Doxorrubicina/química , Doxorrubicina/farmacologia , Humanos , Sistemas de Liberação de Medicamentos , Compostos Organosselênicos/química , Compostos Organosselênicos/farmacologia , Compostos Organosselênicos/síntese química , Compostos de Selênio/química , Compostos de Selênio/síntese química , Peróxido de Hidrogênio/química , Antineoplásicos/química , Antineoplásicos/farmacologia , Antineoplásicos/síntese química
10.
J Exp Bot ; 74(4): 1176-1185, 2023 02 13.
Artigo em Inglês | MEDLINE | ID: mdl-36346644

RESUMO

The phytohormone jasmonate is an essential endogenous signal in the regulation of multiple plant processes for environmental adaptation, such as primary root growth inhibition and root hair elongation. Perception of environmental stresses promotes the accumulation of jasmonate, which is sensed by the CORONATINE INSENSITIVE1 (COI1)-JASMONATE ZIM-DOMAIN (JAZ) co-receptor, triggering the degradation of JAZ repressors and induction of transcriptional reprogramming. The basic helix-loop-helix (bHLH) subgroup IIIe transcription factors MYC2, MYC3, and MYC4 are the most extensively characterized JAZ-binding factors and together stimulate jasmonate-signaled primary root growth inhibition. Conversely, the bHLH subgroup IIId transcription factors (i.e. bHLH3 and bHLH17) physically associate with JAZ proteins and suppress jasmonate-induced root growth inhibition. For root hair development, JAZ proteins interact with and inhibit ROOT HAIR DEFECTIVE 6 (RHD6) and RHD6 LIKE1 (RSL1) transcription factors to modulate jasmonate-enhanced root hair elongation. Moreover, jasmonate also interacts with other signaling pathways (such as ethylene and auxin) to regulate primary root growth and/or root hair elongation. Here, we review recent progress into jasmonate-mediated primary root growth and root hair development.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/metabolismo , Proteínas de Arabidopsis/metabolismo , Fatores de Transcrição/metabolismo , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Ciclopentanos/metabolismo , Oxilipinas/metabolismo , Regulação da Expressão Gênica de Plantas
11.
Plant Cell ; 32(4): 1049-1062, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-31988260

RESUMO

Root hairs arise from trichoblasts and are crucial for plant anchorage, nutrient acquisition, and environmental interactions. The phytohormone jasmonate is known to regulate root hair development in Arabidopsis (Arabidopsis thaliana), but little is known about the molecular mechanism underlying jasmonate modulation in this process. Here, we show that the application of exogenous jasmonate significantly stimulated root hair elongation, but, on the contrary, blocking the perception or signaling of jasmonate resulted in defective root hairs. Jasmonate consistently elevated the expression levels of several crucial genes positively involved in root hair growth. Mechanistic investigation revealed that JASMONATE ZIM-DOMAIN (JAZ) proteins, critical repressors of jasmonate signaling, physically interacted with ROOT HAIR DEFECTIVE 6 (RHD6) and RHD6 LIKE1 (RSL1), two transcription factors that are essential for root hair development. JAZ proteins inhibited the transcriptional function of RHD6 and interfered with the interaction of RHD6 with RSL1. Genetic analysis indicated that jasmonate promoted root hair growth in a RHD6/RSL1-dependent manner. Moreover, overexpression of RHD6 largely rescued the root hair defects of JAZ-accumulating plants. Collectively, our study reveals a key signaling module in which JAZ repressors of the jasmonate pathway directly modulate RHD6 and RSL1 transcription factors to integrate jasmonate signaling and the root hair developmental process.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Ciclopentanos/farmacologia , Oxilipinas/farmacologia , Raízes de Plantas/crescimento & desenvolvimento , Arabidopsis/efeitos dos fármacos , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Modelos Biológicos , Mutação/genética , Fenótipo , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/genética , Plantas Geneticamente Modificadas , Ligação Proteica/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos
12.
Plant Cell ; 32(12): 3846-3865, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-33023956

RESUMO

Abscisic acid (ABA) is known to suppress seed germination and post-germinative growth of Arabidopsis (Arabidopsis thaliana), and jasmonate (JA) enhances ABA function. However, the molecular mechanism underlying the crosstalk between the ABA and JA signaling pathways remains largely elusive. Here, we show that exogenous coronatine, a JA analog structurally similar to the active conjugate jasmonate-isoleucine, significantly enhances the delayed seed germination response to ABA. Disruption of the JA receptor CORONATINE INSENSITIVE1 or accumulation of the JA signaling repressor JASMONATE ZIM-DOMAIN (JAZ) reduced ABA signaling, while jaz mutants enhanced ABA responses. Mechanistic investigations revealed that several JAZ repressors of JA signaling physically interact with ABSCISIC ACID INSENSITIVE3 (ABI3), a critical transcription factor that positively modulates ABA signaling, and that JAZ proteins repress the transcription of ABI3 and ABI5. Further genetic analyses showed that JA activates ABA signaling and requires functional ABI3 and ABI5. Overexpression of ABI3 and ABI5 simultaneously suppressed the ABA-insensitive phenotypes of the coi1-2 mutant and JAZ-accumulating (JAZ-ΔJas) plants. Together, our results reveal a previously uncharacterized signaling module in which JAZ repressors of the JA pathway regulate the ABA-responsive ABI3 and ABI5 transcription factors to integrate JA and ABA signals during seed germination and post-germinative growth.


Assuntos
Aminoácidos/farmacologia , Proteínas de Arabidopsis/metabolismo , Arabidopsis/genética , Indenos/farmacologia , Reguladores de Crescimento de Plantas/metabolismo , Transdução de Sinais/efeitos dos fármacos , Ácido Abscísico/metabolismo , Arabidopsis/efeitos dos fármacos , Arabidopsis/fisiologia , Proteínas de Arabidopsis/genética , Fatores de Transcrição de Zíper de Leucina Básica/genética , Fatores de Transcrição de Zíper de Leucina Básica/metabolismo , Ciclopentanos/metabolismo , Germinação/efeitos dos fármacos , Mutação , Oxilipinas/metabolismo , Fenótipo , Plantas Geneticamente Modificadas , Sementes/efeitos dos fármacos , Sementes/genética , Sementes/metabolismo , Sementes/fisiologia , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
13.
Plant Cell ; 31(7): 1520-1538, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31123050

RESUMO

ABSCISIC ACID INSENSITIVE5 (ABI5) is a crucial regulator of abscisic acid (ABA) signaling pathways involved in repressing seed germination and postgerminative growth in Arabidopsis (Arabidopsis thaliana). ABI5 is precisely modulated at the posttranslational level; however, the transcriptional regulatory mechanisms underlying ABI5 and its interacting transcription factors remain largely unknown. Here, we found that INDUCER OF CBF EXPRESSION1 (ICE1) physically associates with ABI5. ICE1 negatively regulates ABA responses during seed germination and directly suppresses ABA-responsive LATE EMBRYOGENESIS ABUNDANT6 (EM6) and EM1 expression. Genetic analysis demonstrated that the ABA-hypersensitive phenotype of the ice1 mutant requires ABI5. ICE1 interferes with the transcriptional activity of ABI5 to mediate downstream regulons. Importantly, ICE1 also interacts with DELLA proteins, which stimulate ABI5 during ABA signaling. Disruption of ICE1 partially restored the ABA-hyposensitive phenotype of the della mutant, gai-t6 rga-t2 rgl1-1 rgl2-1, indicating that ICE1 functions antagonistically with DELLA in ABA signaling. Consistently, DELLA proteins repress ICE1's transcriptional function and the antagonistic effect of ICE1 on ABI5. Collectively, our study demonstrates that ICE1 antagonizes ABI5 and DELLA activity to maintain the appropriate level of ABA signaling during seed germination, providing a mechanistic understanding of how ABA signaling is fine-tuned by a transcriptional complex involving ABI5 and its interacting partners.


Assuntos
Ácido Abscísico/metabolismo , Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Fatores de Transcrição de Zíper de Leucina Básica/metabolismo , Germinação , Sementes/crescimento & desenvolvimento , Transdução de Sinais , Fatores de Transcrição/metabolismo , Ácido Abscísico/farmacologia , Arabidopsis/efeitos dos fármacos , Arabidopsis/genética , Arabidopsis/crescimento & desenvolvimento , Epistasia Genética/efeitos dos fármacos , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Genes de Plantas , Germinação/efeitos dos fármacos , Modelos Biológicos , Mutação/genética , Fenótipo , Ligação Proteica/efeitos dos fármacos , Sementes/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Transcrição Gênica/efeitos dos fármacos
14.
An Acad Bras Cienc ; 94(2): e20211180, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35674607

RESUMO

The purpose of the study is to further explore the combined effects of exercise and sulfur dioxide (SO2) exposure on the cardiovascular function as well as the underlying mechanisms. Rats were randomly divided into 4 groups: rest group (RG), exercise group (EG), SO2 pollution group (SG) and SO2 pollution + exercise group (SEG). Changes of aortic pressure and left ventricular pressure, Ang II concentration, ACE concentration and ACE activity in rats' myocardial tissue were observed. Compared with RG, the systolic blood pressure, pulse pressure, LVSP, +dp/dtmax and -dp/dtmax of EG increased significantly, diastolic blood pressure, resting heart rate and ACE activity decreased significantly; For rats of SG, 4 weeks SO2 exposure increased LVEDP, Ang II concentration, ACE concentration and ACE activity, decreased the +dp/dtmax and -dp/dtmax; For rats of SEG, the systolic blood pressure, pulse pressure, LVSP, +dp/dtmax and -dp/dtmax decreased significantly, HR, LVEDP, Ang II concentration, ACE concentration and ACE activity increased significantly. Results indicate that, the combination of aerobic exercise and SO2 exposure can aggravate the negative effects of SO2 inhalation on cardiovascular function. Renin-angiotensin system plays an important role in mediating the negative effect of SO2 inhalation.


Assuntos
Miocárdio , Dióxido de Enxofre , Animais , Pressão Sanguínea , Ratos , Dióxido de Enxofre/farmacologia
15.
Environ Microbiol ; 22(1): 107-121, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31608522

RESUMO

Cellulose is a by-product of agricultural production and an abundant waste. As a carbon source, cellulose can be degraded and utilized by fungi. Carbon sources, which act as nutrients, not only provide energy but also serve as regulators of gene expression, metabolism and growth, through various signalling networks that enable cells to sense and adapt to varying environmental conditions. Nutrient-sensing pathways prioritize the use of preferred carbon sources and regulate the production of cellulose-degrading enzymes when necessary. Understanding the regulation of the fungal cellulolytic response will become increasingly important because we strive to increase the efficiency of the utilization of these renewable energy sources. Here, we show that Glsnf1, a sucrose-nonfermenting serine-threonine-protein kinase 1 (Snf1)/AMP-activated protein kinase homologue in medicinal macro basidiomycete Ganoderma lucidum, actively responds to carbon alterations and positively regulates cellulase activity and cellulase-related gene transcription. The carbon catabolite repressor CreA, a zinc binuclear cluster transcription factor that mediates the sensing of nutrients and suppression of the transcription of a number of genes necessary for the consumption of a less preferred carbon source, participates in the Glsnf1-mediated regulation of cellulases. Glsnf1 not only negatively regulates the transcription level of the CreA gene but also hinders its localization in the nucleus. Overall, our findings reveal a key nutrient-sensing mechanism that is critical for the modulation of carbon source adaptation in G. lucidum.


Assuntos
Celulose/metabolismo , Proteínas Fúngicas , Proteínas Serina-Treonina Quinases/metabolismo , Reishi/genética , Reishi/metabolismo , Ureo-Hidrolases , Metabolismo dos Carboidratos/genética , Carbono/metabolismo , Celulase/genética , Celulase/metabolismo , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Regulação Fúngica da Expressão Gênica/efeitos dos fármacos , Ureo-Hidrolases/genética , Ureo-Hidrolases/metabolismo
16.
Appl Microbiol Biotechnol ; 104(16): 7079-7091, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32632475

RESUMO

Identifying new and economical means to utilize diverse lignocellulosic biomass is an urgent task. Ganoderma lucidum is a well-known edible and medicinal basidiomycete with an excellent ability to degrade a wide range of cellulosic biomass, and its nutrient use efficiency is closely related to the activity of extracellular cellulase. Intracellular nicotinamide adenine dinucleotide (NAD+) biosynthesis is controlled in response to nutritional status, and NAD+ is an essential metabolite involved in diverse cellular processes. Nicotinamide mononucleotide adenylyltransferase (NMNAT) is a common enzyme in three NAD+ synthesis pathways. In this study, a homologous gene of nmnat was cloned from G. lucidum and two G. lucidum overexpression strains, OE::nmnat4 and OE::nmnat19, were constructed using an Agrobacterium tumefaciens-mediated transformation method. The G. lucidum nmnat overexpression strains showed obviously increased colony growth on different carbon sources, and intracellular Ca2+ concentrations in the G. lucidum OE::nmnat4 and OE::nmnat19 strains were increased by 2.04- and 2.30-fold, respectively, compared with those in the wild-type (WT) strains. In the G. lucidum OE::nmnat4 and OE::nmnat19 strains, endo-ß-glucanase (CMCase) activity increased by approximately 2.8- and 3-fold, while ß-glucosidase (pNPGase) activity increased by approximately 1.9- and 2.1-fold, respectively, compared with the activity in the WT strains. Furthermore, overexpression of NAD+ synthesis pathways was found to elicit cellulase production by increasing the intracellular Ca2+ concentration. In summary, this study is the first to demonstrate that increased intracellular NAD+ contents through overexpression of the nmnat gene of NAD+ synthesis pathways may increase cellulase production by increasing intracellular Ca2+ concentrations in G. lucidum. KEY POINTS: • The concentration of NAD+influences cellulase production in G. lucidum. • The concentration of NAD+influences the intracellular Ca2+concentration in G. lucidum. • The concentration of NAD+influences cellulase production by eliciting a change in intracellular Ca2+in G. lucidum.


Assuntos
Cálcio/metabolismo , Celulase/biossíntese , Nicotinamida-Nucleotídeo Adenililtransferase/metabolismo , Reishi/enzimologia , Reishi/crescimento & desenvolvimento , Espaço Intracelular/química , NAD/biossíntese , Nicotinamida-Nucleotídeo Adenililtransferase/genética , Reishi/genética
17.
Int J Mol Sci ; 21(4)2020 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-32093420

RESUMO

Erigeron breviscapus (Vant.) Hand.-Mazz. is a famous traditional Chinese medicine that has positive effects on the treatment of cardiovascular and cerebrovascular diseases. With the increase of market demand (RMB 500 million per year) and the sharp decrease of wild resources, it is an urgent task to cultivate high-quality and high-yield varieties of E. breviscapus. However, it is difficult to obtain homozygous lines in breeding due to the self-incompatibility (SI) of E. breviscapus. Here, we first proved that E. breviscapus has sporophyte SI (SSI) characteristics. Characterization of the ARC1 gene in E. breviscapus showed that EbARC1 is a constitutive expression gene located in the nucleus. Overexpression of EbARC1 in Arabidopsis thaliana L. (Col-0) could cause transformation of transgenic lines from self-compatibility (SC) into SI. Yeast two-hybrid (Y2H) and bimolecular fluorescence complementation (BiFC) assays indicated that EbARC1 and EbExo70A1 interact with each other in the nucleus, and the EbARC1-ubox domain and EbExo70A1-N are the key interaction regions, suggesting that EbARC1 may ubiquitinate EbExo70A to regulate SI response. This study of the SSI mechanism in E. breviscapus has laid the foundation for further understanding SSI in Asteraceae and breeding E. breviscapus varieties.


Assuntos
Arabidopsis , Erigeron/genética , Proteínas de Plantas , Plantas Geneticamente Modificadas , Ubiquitina-Proteína Ligases , Arabidopsis/enzimologia , Arabidopsis/genética , Erigeron/enzimologia , Proteínas de Plantas/biossíntese , Proteínas de Plantas/genética , Plantas Geneticamente Modificadas/enzimologia , Plantas Geneticamente Modificadas/genética , Ubiquitina-Proteína Ligases/biossíntese , Ubiquitina-Proteína Ligases/genética
18.
Plant J ; 95(3): 529-544, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29771466

RESUMO

Seed germination and early seedling establishment, critical developmental stages in the life cycle of seed plants, are modulated by diverse endogenous hormones and the surrounding environment. Arabidopsis ABSCISIC ACID-INSENSITIVE5 (ABI5) is a central transcription factor of abscisic acid (ABA) signaling that represses those processes. ABI5 is precisely modulated at post-translational level; however, whether it interacts with other crucial transcriptional regulators remains to be investigated. In this study, VQ18 and VQ26, two members of the recently-identified VQ family, were found to interact with ABI5 in vitro and in vivo. Phenotypic analysis showed that VQ18 and VQ26 are responsive to ABA and negatively mediate ABA signaling redundantly during seed germination. Simultaneously decreasing VQ18 and VQ26 expression levels enhanced ABA signaling to suppress seed germination, whereas overexpressing these two VQ genes resulted in the germinated seeds being less ABA-sensitive. Consistently, the expression levels of several ABI5 targets were modulated by VQ18 and VQ26. The increased ABA signaling of plants in which VQ18 and VQ26 were simultaneously suppressed required ABI5. Additionally, VQ18 and VQ26 acted as negative interactors of the ABI5 transcription factor. Our study reveals a previously unidentified regulatory role of VQ proteins, which act antagonistically with ABI5 to maintain the appropriate ABA signaling level to fine-tune seed germination and early seedling establishment.


Assuntos
Ácido Abscísico/fisiologia , Proteínas de Arabidopsis/fisiologia , Arabidopsis/crescimento & desenvolvimento , Fatores de Transcrição de Zíper de Leucina Básica/fisiologia , Germinação , Proteínas Nucleares/fisiologia , Reguladores de Crescimento de Plantas/fisiologia , Sementes/crescimento & desenvolvimento , Fatores de Transcrição/fisiologia , Ácido Abscísico/metabolismo , Proteínas de Arabidopsis/metabolismo , Fatores de Transcrição de Zíper de Leucina Básica/metabolismo , Núcleo Celular/metabolismo , Germinação/fisiologia , Proteínas Nucleares/metabolismo , Reguladores de Crescimento de Plantas/metabolismo , Fatores de Transcrição/metabolismo
19.
Fungal Genet Biol ; 130: 19-30, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31028914

RESUMO

Hydrogen sulfide (H2S), an emerging small-molecule signalling agent, was recently shown to play a significant role in many physiological processes, but relatively few studies have been conducted on microorganisms compared with mammals and plants. By studying the pretreatment of H2S donor sodium hydrosulfide (NaHS) and the scavenger hypotaurine (HT) and Cystathionine ß-synthase silenced strains, we found that H2S could alleviate the HS-induced ganoderic acids (GAs) biosynthesis. Our transcriptome results also showed that many signaling pathways and metabolic pathways, such as the glycolysis, TCA, oxidative phosphorylation and pentose phosphate pathway, are influenced by H2S. Further experimental results indicated that H2S could affect the physiological process of Ganoderma lucidum by interacting with multiple signals, including ROS, NO, AMPK, sphingolipid, mTOR, phospholipase D and MAPK, and physiological and pharmacological analyses showed that H2S might alleviate the biosynthesis of GAs by inhibiting the intracellular calcium in G. lucidum.


Assuntos
Resposta ao Choque Térmico/fisiologia , Sulfeto de Hidrogênio/farmacologia , Reishi/efeitos dos fármacos , Reishi/metabolismo , Transdução de Sinais/efeitos dos fármacos , Triterpenos/metabolismo , Cálcio/metabolismo , Clonagem Molecular , Cistationina beta-Sintase/genética , Expressão Gênica , Regulação Fúngica da Expressão Gênica , Inativação Gênica , Reishi/genética , Transdução de Sinais/genética , Sulfetos , Taurina/análogos & derivados , Taurina/metabolismo , Transcriptoma , Transformação Genética
20.
Plant Physiol ; 176(4): 2871-2885, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29496884

RESUMO

Stomata are ports that facilitate gas and water vapor exchange between plants and their environment. Stomatal development is strictly regulated by endogenous signals and environmental cues. Jasmonate is an important signal that modulates multiple physiological processes in plants, yet the molecular mechanisms underlying its interactions with other developmental signaling pathways remain poorly understood. Here, we show that jasmonate negatively regulates stomatal development in Arabidopsis (Arabidopsis thaliana) cotyledons. Cotyledons of the wild type and stomata-overproliferating mutants (such as too many mouths-1 and stomatal density and distribution1-1) treated with methyl jasmonate exhibit a clear reduction in stomata number. By contrast, blocking endogenous jasmonate biosynthesis or perception enhanced stomatal development. Moreover, three MYC transcription factors involved in jasmonate signaling, MYC2, MYC3, and MYC4, were found to redundantly modulate jasmonate-inhibited stomatal development. A genetic analysis showed that these MYC proteins act upstream of the SPEECHLESS and FAMA transcription factors to mediate stomatal development. Furthermore, jasmonate repression of stomatal development is dependent on these three MYC transcription factors, as stomatal development of the myc2 myc3 myc4 triple mutant was insensitive to methyl jasmonate treatment. Collectively, our study demonstrates that jasmonate and MYC transcription factors negatively regulate stomatal development in Arabidopsis cotyledons.


Assuntos
Acetatos/farmacologia , Arabidopsis/genética , Cotilédone/genética , Ciclopentanos/farmacologia , Regulação da Expressão Gênica no Desenvolvimento/efeitos dos fármacos , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Oxilipinas/farmacologia , Estômatos de Plantas/genética , Arabidopsis/crescimento & desenvolvimento , Proteínas de Arabidopsis/genética , Cotilédone/crescimento & desenvolvimento , Reguladores de Crescimento de Plantas/farmacologia , Folhas de Planta/genética , Folhas de Planta/crescimento & desenvolvimento , Estômatos de Plantas/crescimento & desenvolvimento , Plantas Geneticamente Modificadas , Plântula/genética , Plântula/crescimento & desenvolvimento , Fatores de Transcrição/genética
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