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1.
Plant Sci ; 309: 110913, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34134840

RESUMO

Abscisic acid (ABA) is an important regulator of plant growth, development, and biotic and abiotic stress responses. Ubiquitination plays important roles in regulating ABA signaling. E3 ligase, a key member in ubiquitination, actively participates in the regulation of biosynthesis, de-repression, and activation of ABA response and degradation of signaling components. In this study, we found that that overexpression of wheat E3 ligase TaPUB1 decreased the sensitivity of wheat seedlings to ABA, whereas TaPUB1-RNA interference (TaPUB1-RNAi) lines increased wheat sensitivity to ABA during germination, root growth, and stomatal opening. TaPUB1 influenced the expression of several ABA-responsive genes, and also interacted with TaPYL4 and TaABI5, which are involved in ABA signal transduction, and promoted their degradation. Additionally, we observed that TaPUB1-OE lines resulted in lower single-split grain numbers, larger seed size, and higher thousand kernel weight, when compared with the WT lines. Contrasting results were obtained for TaPUB1-RNAi lines. It suggests that TaPUB1 acts as a negative regulator in the ABA signaling pathway by interacting with TaPYL4 and TaABI5, subsequently affecting seed development in wheat. In addition, the enhanced abiotic tolerance of overexpression lines due to enhanced photosynthesis and root development may be related to the degradation of TaABI5 by TaPUB1.


Assuntos
Ácido Abscísico/metabolismo , Reguladores de Crescimento de Plantas/metabolismo , Transdução de Sinais , Triticum/genética , Germinação , Fotossíntese , Plântula/genética , Plântula/crescimento & desenvolvimento , Plântula/fisiologia , Sementes/genética , Sementes/crescimento & desenvolvimento , Sementes/fisiologia , Estresse Fisiológico , Triticum/crescimento & desenvolvimento , Triticum/fisiologia , Ubiquitina-Proteína Ligases/genética , Ubiquitina-Proteína Ligases/metabolismo , Ubiquitinação
2.
J Agric Food Chem ; 69(21): 5818-5829, 2021 Jun 02.
Artigo em Inglês | MEDLINE | ID: mdl-34018722

RESUMO

Cadmium (Cd) accumulation in agricultural soils is an increasingly serious problem, as plants absorb Cd, which inhibits their growth and development. Nonetheless, the molecular mechanisms underlying Cd detoxification and accumulation in wheat (Triticum aestivum L.) are unclear. Here, we isolated the U-box E3 ligase TaPUB1 from wheat and reported the functional characterization of TaPUB1 in Cd uptake and tolerance in wheat. Under Cd stress, TaPUB1 overexpression lines displayed higher photosynthetic rates than the wild type; opposite results were observed in the TaPUB1-RNAi lines. In addition, TaPUB1 overexpression lines showed reduced Cd uptake and accumulation, whereas RNAi plants exhibited a significant increase in Cd accumulation after Cd treatment. We further found that TaPUB1 enhanced the resistance of wheat to Cd stress in three ways. First, TaPUB1 interacts with and ubiquitinates TaIRT1, resulting in the inhibition of Cd uptake. Second, TaPUB1 interacts directly with and ubiquitinates TaIAA17, facilitates its degradation, and results in primary root elongation by activating the Aux signaling pathway under Cd stress. Moreover, TaPUB1 decreases ROS accumulation by regulating antioxidant-related gene expression and antioxidant enzyme activity under Cd stress. Thus, a molecular mechanism by which TaPUB1 regulates Cd uptake and tolerance by modulating the stability of TaIRT1 and TaIAA17 proteins was revealed.


Assuntos
Poluentes do Solo , Triticum , Antioxidantes , Transporte Biológico , Cádmio/análise , Cádmio/toxicidade , Fotossíntese , Poluentes do Solo/análise , Triticum/genética
3.
FASEB J ; 35(5): e21609, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33908659

RESUMO

Our purpose was to study the effect of hyperglycemia on macrophage TBK1-HIF-1α-mediated IL-17/IL-10 signaling and its correlation with coronary atherosclerosis. A total of 135 patients with coronary heart disease (CHD) were divided into a stable CHD (SCHD) group (n = 30) and an acute myocardial infarction (AMI) group (n = 105) [nondiabetes mellitus (non-DM)-AMI, n = 60; DM-AMI, n = 45] from January to September 2020. The SYNTAX score and metabolic and inflammatory markers were quantified and compared. THP-1 cell studies and an animal study of coronary intimal hyperplasia were also carried out. We found that the DM-AMI group showed a higher SYNTAX score than the non-DM-AMI group (P < .05). The DM-AMI group showed the highest expression levels of TANK-binding kinase 1 (TBK1), hypoxia-inducible factor 1α (HIF-1α), and interleukin (IL)-17 and the lowest expression level of IL-10, followed by the non-DM-AMI group and the SCHD group (P < .05). THP-1 cell studies showed that BAY87-2243 (a HIF-1α inhibitor) reversed the increase in IL-17 and decrease in IL-10 expression induced by hyperglycemia. Amlexanox (a TBK1 inhibitor) reversed the increase in HIF-1α expression induced by hyperglycemia. Amlexanox treatment resulted in lower coronary artery intimal hyperplasia and a larger lumen area in a diabetic swine model. We conclude that hyperglycemia might aggravate the complexity of coronary atherosclerosis through activation of TBK1-HIF-1α-mediated IL-17/IL-10 signaling. Thus, TBK1 may be a novel drug therapy target for CHD complicated with DM.


Assuntos
Doença da Artéria Coronariana/patologia , Hiperglicemia/complicações , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Interleucina-10/metabolismo , Interleucina-17/metabolismo , Macrófagos/imunologia , Proteínas Serina-Treonina Quinases/metabolismo , Idoso , Animais , Doença da Artéria Coronariana/etiologia , Doença da Artéria Coronariana/metabolismo , Feminino , Humanos , Técnicas In Vitro , Macrófagos/metabolismo , Macrófagos/patologia , Masculino , Pessoa de Meia-Idade , Transdução de Sinais , Suínos
4.
Plant Sci ; 298: 110596, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32771153

RESUMO

Expansins loosen plant cell walls and are involved in cell enlargement and various abiotic stresses. In previous studies, we cloned the expansin gene TaEXPA2 from the wheat cultivar HF9703. Here, we studied its function and regulation in wheat drought stress tolerance. The results indicated that TaEXPA2-overexpressing wheat plants (OE) exhibited drought tolerant phenotypes, whereas down-regulation of TaEXPA2 by RNA interference (RNAi) resulted in elevated drought sensitivity, as measured by survival rate, photosynthetic rate and water containing ability under drought stress. Overexpression of TaEXPA2 enhanced the antioxidant capacity in wheat plants, via elevation of antioxidant enzyme activity and the increase of the transcripts of some ROS scavenging enzyme-related genes. Further investigation revealed that TaEXPA2 positively influenced lateral root formation under drought conditions. A MYB transcription factor of wheat named TaMPS activates TaEXPA2 expression directly by binding to its promoter. Overexpression of TaMPS in Arabidopsis conferred drought tolerance associated with improved lateral root number, and the close homolog genes of TaEXPA2 were up-regulated in Arabidopsis roots overexpressing TaMPS, which suggest that TaMPS may function as one of the regulator of TaEXPA2 gene expression in the root lateral development under drought stress. These findings suggest that TaEXPA2 positively regulates drought stress tolerance in wheat.


Assuntos
Secas , Regulação da Expressão Gênica de Plantas/fisiologia , Proteínas de Plantas/genética , Triticum/fisiologia , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/fisiologia , Interferência de RNA , Estresse Fisiológico/genética , Triticum/genética
5.
Plant Sci ; 294: 110441, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32234224

RESUMO

Various abiotic stresses, including high salinity, affect the growth and yield of crop plants. We isolated a gene, TaPUB26, from wheat that encodes a protein containing a U-box domain and armadillo (ARM) repeats. The TaPUB26 transcript levels were upregulated by high salinity, temperature, drought and phytohormones, suggesting the involvement of TaPUB26 in abiotic stress responses. An in vitro ubiquitination assay revealed that TaPUB26 is an E3 ubiquitin ligase. We overexpressed TaPUB26 in Brachypodium distachyon to evaluate TaPUB26 regulation of salt stress tolerance. Compared with the wild type (WT) line, the overexpression lines showed higher salt stress sensitivity under salt stress conditions, but lower chlorophyll (Chl) content, lower photosynthetic levels and overall reduced salt stress tolerance. Additionally, the transgenic plants showed more severe membrane damage, lower antioxidant enzyme activity and more reactive oxygen species (ROS) accumulation than WT plants under salt stress, which might be related to the changes in the expression levels of some antioxidant genes. In addition, the transgenic plants also had higher Na+ and lower K+ contents, thus maintaining a higher cytosolic Na+/K+ ratio in leaves and roots than that in WT plants. Further analysis of the molecular mechanisms showed that TaPUB26 interacted with TaRPT2a, an ATPase subunit of the 26S proteasome complex in wheat. We speculated that TaPUB26 negatively regulates salt stress tolerance by interacting with other proteins, such as TaRPT2a, and that this mechanism involves altered antioxidant competition and cytosolic Na+/K+ equilibrium.


Assuntos
Brachypodium/efeitos dos fármacos , Brachypodium/enzimologia , Plantas Geneticamente Modificadas/efeitos dos fármacos , Plantas Geneticamente Modificadas/enzimologia , Triticum/enzimologia , Brachypodium/genética , Clorofila/metabolismo , Regulação da Expressão Gênica de Plantas/genética , Regulação da Expressão Gênica de Plantas/fisiologia , Fotossíntese , Plantas Geneticamente Modificadas/genética , Potássio/metabolismo , Complexo de Endopeptidases do Proteassoma/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Estresse Salino/genética , Estresse Salino/fisiologia , Sódio/metabolismo
6.
Metabolism ; 107: 154231, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32298723

RESUMO

BACKGROUND: The mechanism of pyruvate kinase M2 (PKM2)-mediated inflammatory signalling in macrophages when plaques rupture and the impact of hyperglycaemia on the signalling are unclear. The present study aimed to explore the impact of hyperglycaemia on PKM2-mediated NOD-like receptor family pyrin domain containing 3 (NLRP3) inflammasome/stress granule signalling in macrophages and its correlation with plaque vulnerability in vivo and in vitro. METHODS: From July to December 2019, 80 patients with coronary heart disease (CHD) were divided into acute ST-segment elevation myocardial infarction (STEMI) (n = 57) (DM-STEMI, n = 21; non-DM-STEMI, n = 36) and stable CHD (SCHD) groups (n = 23). Circulating mononuclear cells were isolated. The value of peak troponin I (TnI), the Global Registry of Acute Coronary Events (GRACE) risk score, and the expression levels of the related markers were quantified and compared. In vitro studies on the THP-1 cells were also performed. RESULTS: The DM-STEMI group had a higher value of peak TnI and a higher GRACE risk score than the non-DM-STEMI group (p < 0.05). The highest expression levels of PKM2, NLRP3, interleukin (IL)-1ß, and IL-18 and the lowest expression level of GTPase activating protein (SH3 domain)-binding protein 1 (G3BP1) (a stress granule marker protein) were observed in the DM-STEMI group, and they were followed by the non-DM-STEMI group and the SCHD group (p < 0.05). In vitro studies showed similar results and that TEPP-46 (a PKM2 activator) and 2-deoxy-d-glucose (a toxic glucose analogue) reversed the hyperglycaemia-induced increase in the NLRP3 inflammasome and decrease in G3BP1 expression. CONCLUSION: Hyperglycaemia might increase the activation of PKM2-mediated NLRP3 inflammasome/stress granule signalling and increase plaque vulnerability, associating it with worse prognosis. PKM2 may be a novel prognostic indicator and a new target for the treatment of patients with CHD and DM.


Assuntos
Proteínas de Transporte/metabolismo , Grânulos Citoplasmáticos , Hiperglicemia/fisiopatologia , Inflamassomos , Macrófagos/metabolismo , Proteínas de Membrana/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Placa Aterosclerótica/metabolismo , Hormônios Tireóideos/metabolismo , Idoso , Linhagem Celular , Doença das Coronárias/metabolismo , DNA Helicases/sangue , Feminino , Humanos , Hiperglicemia/induzido quimicamente , Interleucinas/sangue , Masculino , Pessoa de Meia-Idade , Proteínas de Ligação a Poli-ADP-Ribose/sangue , RNA Helicases/sangue , Proteínas com Motivo de Reconhecimento de RNA/sangue , Infarto do Miocárdio com Supradesnível do Segmento ST/metabolismo , Troponina I/metabolismo
7.
Front Pharmacol ; 11: 372, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32273846

RESUMO

Objective: This study aimed to explore whether treatment with the glucagon-like peptide-1 (GLP-1) analog liraglutide reduces intimal hyperplasia after coronary stent implantation via regulation of glycemic variability, the NLRP3 inflammasome, and IL-10 in diabetic swine. Methods: Fifteen pigs were divided into a diabetes mellitus (DM) group (n = 6), a DM + liraglutide treatment group (L group) (n = 6) and a sham group (n = 3). A total of 24 everolimus-eluting stents were implanted in the left anterior descending and right coronary arteries at 3 weeks. A novel continuous glucose monitoring system (GMS) was used for 2 weeks. The means and standard deviations (SDs) were measured and calculated by the GMS. At 22 weeks, the lumen area (LA), neointimal thickness (NIT), neointimal area (NIA), and percent area stenosis (%AS) were analyzed by optical coherence tomography. Plasma tumor necrosis factor-α, interleukin-6, and interleukin-10 were assayed by ELISA. The intima protein expression levels of NLRP3, interleukin-1ß, interleukin-18 and interleukin-10 were examined using Western blot analysis. Histology was used to evaluate the healing response. In an in vitro study, THP-1 cells were divided into control, high glucose (HG), HG + liraglutide, and HG + liraglutide + Exe(9-39) (a GLP-1 receptor inhibitor) groups. Results: The L group had a lower SD, NIT, NIA, and %AS; a larger LA; reduced inflammation and injury scores; lower expression levels of tumor necrosis factor-α, interleukin-6, NLRP3, interleukin-1ß, and interleukin-18; and higher expression of interleukin-10 compared with those of the DM group (p < 0.05). In the in vitro study, similar results were obtained in the HG + liraglutide group, and Exe(9-39) abolished the effect of liraglutide (p < 0.05). Conclusions: Liraglutide treatment reduces intimal hyperplasia after stent implantation via regulation of glycemic variability, the NLRP3 inflammasome, and IL-10 in diabetic pigs in a GLP-1 receptor-dependent manner. Reducing the inflammation induced by glycemic variability may be one of the cardioprotective mechanisms of liraglutide.

8.
Plant Cell Rep ; 39(5): 653-667, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32123996

RESUMO

KEY MESSAGE: The TaMP gene from wheat encodes an α-mannosidase induced by salt stress that functions as negative regulator of salt tolerance in plants. Salt stress significantly affects growth and yield of crop plants. The α-mannosidases function in protein folding, trafficking, and endoplasmic reticulum-associated degradation in eukaryotic cells, and they are involved in abiotic stress tolerance in plants. Previously, we identified the α-mannosidase gene TaMP in wheat (Triticum aestivum). In this study, we investigated the function of TaMP in salt stress tolerance. TaMP expression was induced in wheat leaves by salt, drought, abscisic acid, and H2O2 treatments. Overexpressing TaMP in Brachypodium distachyon was associated with a salt-sensitive phenotype. Under salt stress, the overexpressing plants had reduced height, delayed growth status, low photosynthetic rate, decreased survival rate, and diminished yield. Moreover, the overexpression of TaMP aggravated the tendency for ions to become toxic under salt stress by significantly affecting the Na+ and K+ contents in cells. In addition, TaMP could negatively regulate salt tolerance by affecting the antioxidant enzyme system capacity and increasing the reactive oxygen species accumulation. Our study was helpful to understand the underlying physiological and molecular mechanisms of salt stress tolerance in plants.


Assuntos
Brachypodium/crescimento & desenvolvimento , Folhas de Planta/crescimento & desenvolvimento , Tolerância ao Sal/genética , Triticum/enzimologia , alfa-Manosidase/metabolismo , Ácido Abscísico/farmacologia , Antioxidantes/metabolismo , Brachypodium/efeitos dos fármacos , Brachypodium/genética , Brachypodium/fisiologia , Núcleo Celular/genética , Núcleo Celular/metabolismo , Secas , Retículo Endoplasmático/genética , Retículo Endoplasmático/metabolismo , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Peróxido de Hidrogênio/farmacologia , Fotossíntese/efeitos dos fármacos , Folhas de Planta/efeitos dos fármacos , Folhas de Planta/metabolismo , Folhas de Planta/fisiologia , Plantas Geneticamente Modificadas , Potássio/análise , Potássio/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Sódio/análise , Sódio/metabolismo , Sódio/farmacologia , Triticum/genética , Regulação para Cima , alfa-Manosidase/genética
9.
J Integr Plant Biol ; 62(5): 631-651, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-31119835

RESUMO

U-box E3 ubiquitin ligases play important roles in the ubiquitin/26S proteasome machinery and in abiotic stress responses. TaPUB1-overexpressing wheat (Triticum aestivum L.) were generated to evaluate its function in salt tolerance. These plants had more salt stress tolerance during seedling and flowering stages, whereas the TaPUB1-RNA interference (RNAi)-mediated knock-down transgenic wheat showed more salt stress sensitivity than the wild type (WT). TaPUB1 overexpression upregulated the expression of genes related to ion channels and increased the net root Na+ efflux, but decreased the net K+ efflux and H+ influx, thereby maintaining a low cytosolic Na+ /K+ ratio, compared with the WT. However, RNAi-mediated knock-down plants showed the opposite response to salt stress. TaPUB1 could induce the expression of some genes that improved the antioxidant capacity of plants under salt stress. TaPUB1 also interacted with TaMP (Triticum aestivum α-mannosidase protein), a regulator playing an important role in salt response in yeast and in plants. Thus, low cytosolic Na+ /K+ ratios and better antioxidant enzyme activities could be maintained in wheat with overexpression of TaPUB1 under salt stress. Therefore, we conclude that the U-box E3 ubiquitin ligase TaPUB1 positively regulates salt stress tolerance in wheat.


Assuntos
Triticum/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , Regulação da Expressão Gênica de Plantas , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/metabolismo , Estresse Fisiológico/genética , Estresse Fisiológico/fisiologia , Triticum/genética , Ubiquitina-Proteína Ligases/genética
10.
Front Plant Sci ; 10: 1242, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31649704

RESUMO

The phytohormone abscisic acid (ABA) regulates plant growth and development, as well as responses to various stresses, such as salt and drought. The wheat TaFBA1 gene, which encodes an F-box protein, was previously identified in our laboratory by homologous cloning. We previously found that TaFBA1 expression was induced by ABA and drought stress. In this study, wild-type (WT), TaFBA1 over-expressing (OEs), TaFBA1 homologous gene mutants, and TaFBA1 recovery (Rs) Arabidopsis plants were used. We found that the germination rate, the cotyledon greening rate, the root length, and the photosynthetic performance of TaFBA1 OE plants were better than those of WT under drought and ABA conditions, but mutant plants showed the opposite trend, and overexpression of TaFBA1 in mutants can recover their phenotype. In addition, TaFBA1 was found to be a negative regulator of ABA-induced stoma movement; mRNA transcription of certain ABA signaling-related genes was lower in TaFBA1 OE plants than in WT plants following ABA treatment. Further, we found that TaFBA1 can interact with RCAR1 (an ABA receptor) and ABI5. BiFC assay showed that TaFBA1 may interact with RCAR1 in the plasma membrane. In addition, accumulation of ROS and MDA in TaFBA1 OE plants was lower than that in the WT plants after ABA and drought treatments. Based on these results, we suggest that TaFBA1-regulated ABA insensitivity may be dependent on regulating ABA-mediated gene expression through interacting with RCAR1 and ABI5. Increased antioxidant competence and decreased ROS accumulation may be an important mechanism that underlies improved drought tolerance in TaFBA1 OE plants.

11.
Plant Sci ; 278: 70-79, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30471731

RESUMO

In the present study on a wheat stay-green mutant, tasg1, we found that its delayed senescence at the late filling stage was related to the high cytokinin (CK) and N contents. RNA sequencing suggested that several genes may be responsible for the different senescence processes between wild-type (WT) and tasg1 plants. WT and tasg1 seedlings were treated with NH4NO3, lovastatin, and 6-benzylaminopurine (BAP), and the results suggested that the feedback of CK with N content regulated the leaf senescence in the tasg1 plants. Furthermore, a knock-out of the candidate gene cisZOGT1 (catalytic O-glucosylation in cis-zeatin) in the wheat mutant pool 'Kronos' exhibited delayed senescence at the late grain filling stage. Overall, our results suggested the cisZOGT1 gene has an important role in regulating wheat leaf senescence by regulating CK and N metabolism. At the same time, CK and N metabolism involved in delayed flag leaf senescence of tasg1 may be by a feedback pattern.


Assuntos
Citocininas/metabolismo , Nitrogênio/metabolismo , Triticum/metabolismo , Técnicas de Inativação de Genes , Folhas de Planta/genética , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Proteínas de Plantas/fisiologia , Análise de Sequência de RNA , Triticum/genética , Triticum/crescimento & desenvolvimento
12.
Front Plant Sci ; 9: 521, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29740462

RESUMO

Adverse environmental conditions, including high temperature, often affect the growth and production of crops worldwide. F-box protein, a core component of the Skp1-Cullin-F-box (SCF) E3 ligase complex, plays an important role in abiotic stress responses. A previously cloned gene from wheat, TaFBA1, encodes a homologous F-box protein. A Yeast two-Hybrid (Y2H) assay showed that TaFBA1 interacted with other SCF proteins. We found that the expression of TaFBA1 could be induced by heat stress (45°C). Overexpression of TaFBA1 enhanced heat stress tolerance in transgenic tobacco, because growth inhibition was reduced and photosynthesis increased as compared with those in the wild type (WT) plants. Furthermore, the accumulation of H2O2, O2-, and carbonyl protein decreased and cell damage was alleviated in transgenic plants under heat stress, which resulted in less oxidative damage. However, the transgenic plants contained more enzymatic antioxidants after heat stress, which might be related to the regulation of some antioxidant gene expressions. The qRT-PCR analysis showed that the overexpression of TaFBA1 upregulated the expression of genes involved in reactive oxygen species (ROS) scavenging, proline biosynthesis, and abiotic stress responses. We identified the interaction of TaFBA1 with Triticum aestivum stress responsive protein 1 (TaASRP1) by Y2H assay and bimolecular fluorescence complementation (BiFC) assay. The results suggested that TaFBA1 may improve enzymatic antioxidant levels and regulate gene expression by interacting with other proteins, such as TaASRP1, which leads to the enhanced heat stress tolerance seen in the transgenic plants.

13.
Plant Cell Rep ; 36(11): 1801-1814, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28808769

RESUMO

KEY MESSAGE: Freezing tolerance in taft plants relied more upon an ABA-independent- than an ABA-dependent antifreeze signaling pathway. Two wheat (Triticum aestivum) near isogenic lines (NIL) named tafs (freezing sensitivity) and taft (freezing tolerance) were isolated in the laboratory and their various cytological and physiological characteristics under freezing conditions were studied. Proplastid, cell membrane, and mitochondrial ultrastructure were less damaged by freezing treatment in taft than tafs plants. Chlorophyll, ATP, and thylakoid membrane protein contents were significantly higher, but malondialdehyde content was significantly lower in taft than tafs plants under freezing condition. Antioxidant capacity, as indicated by reactive oxygen species accumulation and antioxidant enzyme activity, and the relative gene expression were significantly greater in taft than tafs plants. Soluble sugars and abscisic acid (ABA) contents were significantly higher in taft plants than in tafs plants under both normal and freezing conditions. The upregulated expression levels of certain freezing tolerance-related genes were greater in taft than tafs plants under freezing treatment. The addition of sodium tungstate, an ABA synthesis inhibitor, led to only partial freezing tolerance inhibition in taft plants and the down-regulated expression of some ABA-dependent genes. Thus, both ABA-dependent and ABA-independent signaling pathways are involved in the freezing tolerance of taft plants. At the same time, freezing tolerance in taft plants relied more upon an ABA-independent- than an ABA-dependent antifreeze signaling pathway.


Assuntos
Proteínas de Plantas/genética , Triticum/genética , Ácido Abscísico/farmacologia , Congelamento , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Regulação da Expressão Gênica de Plantas/genética , Plantas Geneticamente Modificadas/genética , Triticum/efeitos dos fármacos
14.
Sci Rep ; 7(1): 7549, 2017 08 08.
Artigo em Inglês | MEDLINE | ID: mdl-28790447

RESUMO

E3 ligases play significant roles in plant stress tolerance by targeting specific substrate proteins for post-translational modification. In a previous study, we cloned TaPUB1 from Triticum aestivum L., which encodes a U-box E3 ligase. Real-time polymerase chain reaction revealed that the gene was up-regulated under drought stress. To investigate the function of TaPUB1 in the response of plants to drought, we generated transgenic Nicotiana benthamiana (N. benthamiana) plants constitutively expressing TaPUB1 under the CaMV35S promoter. Compared to wild type (WT), the transgenic plants had higher germination and seedling survival rates as well as higher photosynthetic rate and water retention, suggesting that the overexpression of TaPUB1 enhanced the drought tolerance of the TaPUB1 overexpressing (OE) plants. Moreover, less accumulation of reactive oxygen species (ROS) and stronger antioxidant capacity were detected in the OE plants than in the WT plants. To characterize the mechanisms involved, methyl viologen (MV) was used to induce oxidative stress conditions and we identified the functions of this gene in the plant tolerance to oxidative stress. Our results suggest that TaPUB1 positively modulates plant drought stress resistance potential by improving their antioxidant capacity.


Assuntos
Adaptação Fisiológica/genética , Antioxidantes/metabolismo , Secas , Proteínas de Plantas/genética , Triticum/genética , Ubiquitina-Proteína Ligases/genética , Regulação da Expressão Gênica de Plantas , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas , Espécies Reativas de Oxigênio/metabolismo , Plântula/genética , Plântula/metabolismo , Estresse Fisiológico , Triticum/metabolismo , Ubiquitina-Proteína Ligases/metabolismo
15.
PLoS One ; 11(8): e0161351, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27580166

RESUMO

A wheat stay-green mutant, tasg1, was observed to exhibit significantly delayed senescence in the late developmental stage. The photosynthetic capacity of the flag leaf was greater in tasg1 than in wild type (WT) plants. In addition, the grain volume of tasg1 was significantly higher than that of WT at the early filling stage. The content of various cytokinins (CKs) in the grain was significantly higher in tasg1 than in WT and was accompanied by an upregulated expression of some cell cycle-related genes. Examination of the metabolism of soluble sugars in tasg1 and WT revealed that the concentrations of glucose (Glu), fructose (Fru), and sucrose (Suc) were higher in the flag leaves and grains of tasg1 than in WT plants. The activities of sucrose-phosphate synthase (SPS), sucrose synthase (SuSy), and cell wall invertase (CW-invertase) were higher in tasg1, suggesting an altered metabolism and transport of soluble sugars. Furthermore, when tasg1 was treated with the CK inhibitor lovastatin, the activity of invertase was inhibited and was associated with premature senescence phenotype. However, the activity of invertase was partially recovered in tasg1 when treated with 6-benzylaminopurine (BAP). The trend of change in the concentrations of Glu, Fru, and Suc was similar to that of invertase. Our results suggest that CKs might regulate the stay-green phenotype of tasg1 by regulating the invertase activity involved in Suc remobilization.


Assuntos
Ciclo Celular , Citocininas/metabolismo , Regulação da Expressão Gênica de Plantas , Mutação , Proteínas de Plantas/biossíntese , Sacarose/metabolismo , Triticum/metabolismo , Citocininas/genética , Regulação Enzimológica da Expressão Gênica , Fenótipo , Proteínas de Plantas/genética , Triticum/genética
16.
Plant Cell Rep ; 35(3): 585-99, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26650838

RESUMO

KEY MESSAGE: By measuring the cytokinin content directly and testing the sensitivity to the cytokinin inhibitor lovastatin, we demonstrated that tasg1 cytokinin metabolism is different from wild-type. Our previous studies have indicated that compared with wild-type (WT) plants, a wheat stay-green mutant tasg1 exhibited delayed senescence. In this study, we found that the root development of tasg1 occurred later than that of WT. The number of lateral roots was fewer, but the lateral root length was longer in tasg1 than in WT, which resulted in a lower root to shoot ratio in tasg1 than WT. The levels of cytokinin (CK), CK activity, and expression of CK metabolic genes were measured. We found that the total CK content in the root tips and leaf of tasg1 was greater than in WT. The accumulation of mRNA of the CK synthetic gene (TaIPT) in tasg1 was higher than in WT at 9 and 11 days during seedling growth, but the expression of CK oxidase gene (TaCKX) was significantly lower in tasg1. Furthermore, the CK inhibitor lovastatin was used to inhibit CK activity. When treated with lovastatin, both the chlorophyll content and thylakoid membrane protein stability were significantly lower in tasg1 than WT, consistent with the inhibited expression of senescence-associated genes (TaSAGs) in tasg1. Lovastatin treatment also inhibited the antioxidative capability of wheat seedlings, and tasg1 was more sensitive to lovastatin than WT, as indicated by the MDA content, protein carbonylation, and antioxidant enzyme activity. The decreased antioxidative capability after lovastatin treatment may be related to the down-regulation of some antioxidase genes. These results suggest that the CK metabolism was altered in tasg1, which may play an important role in its ability to delay senescence.


Assuntos
Citocininas/metabolismo , Mutação , Proteínas de Plantas/genética , Triticum/genética , Clorofila/metabolismo , Citocininas/antagonistas & inibidores , Regulação da Expressão Gênica no Desenvolvimento/efeitos dos fármacos , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Immunoblotting , Lovastatina/farmacologia , Malondialdeído/metabolismo , Redes e Vias Metabólicas/genética , Fenótipo , Folhas de Planta/genética , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/metabolismo , Proteínas de Plantas/metabolismo , Raízes de Plantas/genética , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/metabolismo , Carbonilação Proteica/efeitos dos fármacos , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fatores de Tempo , Triticum/crescimento & desenvolvimento , Triticum/metabolismo
17.
Zhong Nan Da Xue Xue Bao Yi Xue Ban ; 34(6): 563-5, 2009 Jun.
Artigo em Chinês | MEDLINE | ID: mdl-19587443

RESUMO

OBJECTIVE: To determine the effect of alendronate on glucocorticoid-induced osteoporosis(GIO). METHODS: Thirty-five GIO patients were enrolled. Ten milligrams alendronate were prescribed daily for 6 months. Bone mineral density (BMD) was measured by dual-energy X-ray absorptiometer (DEXA) after and before the treatment. RESULTS: BMD at lumbar, neck and trochanter sites of the 35 patients after the treatment was significantly increased compared with those before the treatment (P<0.05). Urine Ca/Cr level was decreased (P<0.05). There was no severe side effect. CONCLUSION: Alendronate is effective and well tolerated for GIO.


Assuntos
Alendronato/uso terapêutico , Conservadores da Densidade Óssea/uso terapêutico , Osteoporose/tratamento farmacológico , Prednisona/efeitos adversos , Febre Reumática/tratamento farmacológico , Adulto , Densidade Óssea/efeitos dos fármacos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Osteoporose/induzido quimicamente , Prednisona/uso terapêutico
18.
Zhonghua Liu Xing Bing Xue Za Zhi ; 27(4): 339-42, 2006 Apr.
Artigo em Chinês | MEDLINE | ID: mdl-16875540

RESUMO

OBJECTIVE: To determine whether Acanthamoeba polyphaga could affect the survival and growth of Vibrio cholerae O139 in low temperature. METHODS: V. cholerae O139 was co-cultured with the Acanthamoeba polyphaga to be examined on its intracellular growth and survival rate within cysts at low temperature, using methods as Gram-staining, electron microscope and passage culture. RESULTS: V. cholerae O139 were observed to enter into the trophozoites and grow the within the vacuoles after 8 hour incubation with Acanthamoeba polyphaga. The germs survived in the vacuole and/or endo-layer of wall and could be re-isolated from the excystment of Acanthamoeba polyphaga. At 30 degrees C, V. cholerae O139 could survive for 120 days with the amoeba while less than 45 days in PAS. At 4 degrees C, the number of viable bacteria decreased and reached undetectable levels for both study and control groups after a 30-day incubation. V. cholerae O139 could be re-isolated from the 30-, 45-, 60- and 75-day's infected cysts after excystment. However the ability of excystment for 90-day's infected cysts decreased and V. cholerae O139 within the cyst could not be isolated again because the amoebae had lysed. CONCLUSION: These findings indicated that V. cholerae O139 could grow within Acanthamoeba polyphaga and the survival time could be increased in the cysts at low temperature. It seemed that Acanthamoeba can provide an environmental reservoir for V. cholerae O139.


Assuntos
Acanthamoeba/microbiologia , Vibrio cholerae/crescimento & desenvolvimento , Cápsulas Bacterianas , Contagem de Colônia Microbiana , Temperatura
19.
Zhonghua Liu Xing Bing Xue Za Zhi ; 26(3): 204-6, 2005 Mar.
Artigo em Chinês | MEDLINE | ID: mdl-15941511

RESUMO

OBJECTIVE: To study the survival and growth of Vibrio cholerae inside the Acanthamoeba polyphage. METHODS: Survival and growth of Vibro cholerae O139, co-cultured with Acanthamoeba polyphaga, was observed inside the trophozoites and cysts, using Gram stain and electron microscope. RESULTS: Viable O139 was observed inside the amoebal vacuoles in 24 hours. Vacuoles were filled with more bacteria along with the longer period of co-culture. The process of O139 infection with Amoebae would include uptake, formation of O139 vacuole, multiplication, trophozoites lysed and expel under electron microscopy. Some infected trophozoites could subsequently encyst and the surviving O139 could locate in the vesicles inside the cysts. CONCLUSION: O139 might survive and multiply in the trophozoites and reside inside the cysts of Amoebae, suggesting that Acanthamoebae might serve as one of the environmental hosts of Vibro cholerae.


Assuntos
Acanthamoeba/crescimento & desenvolvimento , Acanthamoeba/microbiologia , Vibrio cholerae O139/crescimento & desenvolvimento , Acanthamoeba/ultraestrutura , Animais , Técnicas de Cocultura , Contagem de Colônia Microbiana , Meios de Cultura , Vibrio cholerae O139/ultraestrutura , Água/parasitologia
20.
Artigo em Chinês | MEDLINE | ID: mdl-16566221

RESUMO

OBJECTIVE: To establish a method for co-culture of amoebae and endosymbionts, also for continuously observing the microphenotype of amoebae. METHODS: 24 wells culture plate with cover glass on the wells was used as containers. Amoebae and Candida albicans were co-cultured in microdrop of medium in the wells at 37 degrees C, and observed under x1000. RESULTS: Continuous observation revealed trophozoites in various shapes like letters T, K, or Y, their movement and ingestion phenomenon were observed. CONCLUSION: The micro-culture method is useful in observing the amoebal morphology and its phagocytic process to Candida albicans.


Assuntos
Amoeba/crescimento & desenvolvimento , Amoeba/fisiologia , Animais , Candida albicans , Técnicas de Cocultura , Meios de Cultura , Fagocitose , Temperatura
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