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1.
Ann Noninvasive Electrocardiol ; 27(4): e12966, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35567783

RESUMO

BACKGROUND: Complete right bundle branch block (CRBBB) is an important predictor of atrial fibrillation (AF) recurrence after pulmonary vein isolation. However, the association between CRBBB and AF development remains unclear. METHODS: We performed a retrospective study of 2639 patients (male, n = 1549; female, n = 1090; mean age, 58 ± 13 years). CRBBB was defined as a late R (R') wave in lead V1 or V2 with a slurred S wave in lead I and/or lead V6 with a prolonged QRS duration (≥120 ms). RESULTS: Among the 2639 patients, CRBBB was detected in 40 patients (1.5%), and the prevalence of AF was 7.4% (196/2639). The proportion of patients with AF and CRBBB was higher than the proportion of patients with AF without CRBBB (22.5% vs. 7.2%; p = 0.001). In the forward multivariate logistic analysis, CRBBB (odds ratio [OR], 3.329; 95% confidence interval [CI], 1.350-8.211; p = 0.009), complete left bundle branch block (OR, 2.209; 95% CI, 1.238-3.940; p = 0.007), age (OR, 1.020; 95% CI, 1.005-1.035; p = 0.009), valvular heart disease (OR, 2.332; 95% CI, 1.531-3.552; p < 0.001), left atrial diameter (OR, 1.133; 95% CI, 1.104-1.163; p < 0.001), left ventricular ejection fraction (OR, 1.023; 95% CI, 1.006-1.041; p = 0.007), and class I or III anti-arrhythmic drug use (OR, 10.534; 95% CI, 7.090-15.651; p < 0.001) were associated with AF. CONCLUSION: Complete right bundle branch block was significantly associated with AF development in hospitalized patients with cardiovascular diseases.


Assuntos
Fibrilação Atrial , Bloqueio de Ramo , Idoso , Fibrilação Atrial/complicações , Fibrilação Atrial/epidemiologia , Bloqueio de Ramo/complicações , Bloqueio de Ramo/diagnóstico , Bloqueio de Ramo/epidemiologia , Eletrocardiografia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Volume Sistólico , Função Ventricular Esquerda
2.
J Cell Mol Med ; 25(14): 6746-6759, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-34132026

RESUMO

Fibrosis serves a critical role in driving atrial remodelling-mediated atrial fibrillation (AF). Abnormal levels of the transcription factor PU.1, a key regulator of fibrosis, are associated with cardiac injury and dysfunction following acute viral myocarditis. However, the role of PU.1 in atrial fibrosis and vulnerability to AF remain unclear. Here, an in vivo atrial fibrosis model was developed by the continuous infusion of C57 mice with subcutaneous Ang-II, while the in vitro model comprised atrial fibroblasts that were isolated and cultured. The expression of PU.1 was significantly up-regulated in the Ang-II-induced group compared with the sham/control group in vivo and in vitro. Moreover, protein expression along the TGF-ß1/Smads pathway and the proliferation and differentiation of atrial fibroblasts induced by Ang-II were significantly higher in the Ang-II-induced group than in the sham/control group. These effects were attenuated by exposure to DB1976, a PU.1 inhibitor, both in vivo and in vitro. Importantly, in vitro treatment with small interfering RNA against Smad3 (key protein of TGF-ß1/Smads signalling pathway) diminished these Ang-II-mediated effects, and the si-Smad3-mediated effects were, in turn, antagonized by the addition of a PU.1-overexpression adenoviral vector. Finally, PU.1 inhibition reduced the atrial fibrosis induced by Ang-II and attenuated vulnerability to AF, at least in part through the TGF-ß1/Smads pathway. Overall, the study implicates PU.1 as a potential therapeutic target to inhibit Ang-II-induced atrial fibrosis and vulnerability to AF.


Assuntos
Fibrilação Atrial/metabolismo , Proteínas Proto-Oncogênicas/antagonistas & inibidores , Proteína Smad3/metabolismo , Transativadores/antagonistas & inibidores , Fator de Crescimento Transformador beta/metabolismo , Angiotensina II/toxicidade , Animais , Fibrilação Atrial/tratamento farmacológico , Fibrilação Atrial/etiologia , Cardiotônicos/farmacologia , Cardiotônicos/uso terapêutico , Células Cultivadas , Fibrose , Compostos Heterocíclicos/farmacologia , Compostos Heterocíclicos/uso terapêutico , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Miocárdio/metabolismo , Miocárdio/patologia , Miofibroblastos/efeitos dos fármacos , Miofibroblastos/metabolismo , Miofibroblastos/patologia , Proteínas Proto-Oncogênicas/metabolismo , Transdução de Sinais , Transativadores/metabolismo
3.
BMC Cardiovasc Disord ; 21(1): 587, 2021 12 07.
Artigo em Inglês | MEDLINE | ID: mdl-34876011

RESUMO

BACKGROUND: In patients with atrial fibrillation (AF) and functional mitral regurgitation (MR), catheter ablation reduces the severity of MR and improves cardiac remodeling. However, its effects on prognosis are uncertain. METHODS: This retrospective study included 151 consecutive patients with AF and functional MR, 82 (54.3%) of whom were treated by catheter ablation (Ablation group) and 69 (45.7%) with drug therapy without ablation (Non-ablation group). Forty-three pairs of these patients were propensity matched on the basis of age, CHA2DS2-VASc scores, and left ventricular ejection fraction. The primary outcome evaluated was severity of MR, cardiac remodeling and the combined incidence of subsequent heart failure-related hospitalization and strokes/transient ischemic attacks. RESULTS: Patients in the Ablation group showed a significant decrease in the severity of MR (p < 0.001), a significant decrease in the left atrial diameter (p = 0.010), and significant improvement in the left ventricular ejection fraction (p = 0.015). However, patients in the Non-ablation group showed only a significant decrease in the severity of MR (p = 0.004). The annual incidence of the studied events was 4.9% in the Ablation group and 16.7% in the Non-ablation group, the incidence being significantly lower in the ablation than Non-ablation group (p = 0.026) according to Kaplan-Meier curve analyses. According to multivariate Cox regression analysis, catheter ablation therapy (hazard ratio [HR] 0.27, 95% confidence interval [CI] 0.09-0.84; p = 0.024) and heart failure at baseline (HR 3.84, 95% CI 1.07-13.74; p = 0.038) were independent predictors of the incidence of the studied events. CONCLUSIONS: Among patients with AF and functional MR, catheter ablation was associated with a significantly lower combined risk of heart failure-related hospitalization and stroke than in a matched cohort of patients receiving drug therapy alone.


Assuntos
Antiarrítmicos/uso terapêutico , Fibrilação Atrial/terapia , Ablação por Cateter , Insuficiência da Valva Mitral/fisiopatologia , Valva Mitral/fisiopatologia , Potenciais de Ação , Idoso , Antiarrítmicos/efeitos adversos , Fibrilação Atrial/complicações , Fibrilação Atrial/diagnóstico , Fibrilação Atrial/fisiopatologia , Ablação por Cateter/efeitos adversos , Feminino , Insuficiência Cardíaca/etiologia , Insuficiência Cardíaca/fisiopatologia , Insuficiência Cardíaca/terapia , Frequência Cardíaca , Humanos , Ataque Isquêmico Transitório/etiologia , Masculino , Pessoa de Meia-Idade , Valva Mitral/diagnóstico por imagem , Insuficiência da Valva Mitral/complicações , Insuficiência da Valva Mitral/diagnóstico por imagem , Recuperação de Função Fisiológica , Estudos Retrospectivos , Índice de Gravidade de Doença , Acidente Vascular Cerebral/etiologia , Fatores de Tempo , Resultado do Tratamento
4.
Planta ; 252(1): 1, 2020 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-32504137

RESUMO

MAIN CONCLUSION: Maize has a set of dark response genes, expression of which is influenced by multiple factor and varies with maize inbred lines but without germplasm specificity. The response to photoperiod is a common biological issue across the species kingdoms. Dark is as important as light in photoperiod. However, further in-depth understanding of responses of maize (Zea mays) to light and dark transition under photoperiod is hindered due to the lack of understanding of dark response genes. With multiple public "-omic" datasets of temperate and tropical/subtropical maize, 16 maize dark response genes, ZmDRGs, were found and had rhythmic expression under dark and light-dark cycle. ZmDRGs 6-8 were tandemly duplicated. ZmDRGs 2, 13, and 14 had a chromosomal collinearity with other maize genes. ZmDRGs 1-11 and 13-16 had copy-number variations. ZmDRGs 2, 9, and 16 showed 5'-end sequence deletion mutations. Some ZmDRGs had chromatin interactions and underwent DNA methylation and/or m6A mRNA methylation. Chromosomal histones associated with 15 ZmDRGs were methylated and acetylated. ZmDRGs 1, 2, 4, 9, and 13 involved photoperiodic phenotypes. ZmDRG16 was within flowering-related QTLs. ZmDRGs 1, 3, and 6-11 were present in cis-acting expression QTLs (eQTLs). ZmDRGs 1, 4, 6-9, 11, 12, and 14-16 showed co-expression with other maize genes. Some of ZmDRG-encoded ZmDRGs showed obvious differences in abundance and phosphorylation. CONCLUSION: Sixteen ZmDRGs 1-16 are associated with the dark response of maize. In the process of post-domestication and/or breeding, the ZmDRGs undergo the changes without germplasm specificity, including epigenetic modifications, gene copy numbers, chromatin interactions, and deletion mutations. In addition to effects by these factors, ZmDRG expression is influenced by promoter elements, cis-acting eQTLs, and co-expression networks.


Assuntos
Regulação da Expressão Gênica de Plantas , Proteínas de Plantas/metabolismo , Locos de Características Quantitativas/genética , Zea mays/genética , Ritmo Circadiano , Fotoperíodo , Proteínas de Plantas/genética , Zea mays/fisiologia , Zea mays/efeitos da radiação
5.
Planta ; 250(5): 1621-1635, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31399791

RESUMO

MAIN CONCLUSION: Cassava AGPase and AGPase genes have some unique characteristics. ADP-glucose pyrophosphorylase (AGPase) is a rate-limiting enzyme for starch synthesis. In this study, cassava AGPase genes (MeAGP) were analyzed based on six cultivars and one wild species. A total of seven MeAGPs was identified, including four encoding AGPase large subunits (MeAGPLs 1, 2, 3 and 4) and three encoding AGPase small subunits (MeAGPSs 1, 2 and 3). The copy number of MeAGPs varied in cassava germplasm materials. There were 14 introns for MeAGPLs 1, 2 and 3, 13 introns for MeAGPL4, and 8 introns for other three MeAGPSs. Multiple conservative amino acid sequence motifs were found in the MeAGPs. There were differences in amino acids at binding sites of substrates and regulators among different MeAGP subunits and between MeAGPs and a potato AGPase small subunit (1YP2:B). MeAGPs were all located in chloroplasts. MeAGP expression was not only associated with gene copy number and types/combinations, regions and levels of the DNA methylation but was also affected by environmental factors with the involvement of various transcription factors in multiple regulation networks and in various cis-elements in the gene promoter regions. The MeAGP activity also changed with environmental conditions and had potential differences among the subunits. Taken together, MeAGPs differ in number from those of Arabidopsis, potato, maize, banana, sweet potato, and tomato.


Assuntos
Variações do Número de Cópias de DNA , Genoma de Planta/genética , Glucose-1-Fosfato Adenililtransferase/genética , Manihot/enzimologia , Motivos de Aminoácidos , Sítios de Ligação , Cloroplastos/metabolismo , Evolução Molecular , Manihot/genética , Proteínas de Plantas/genética , Subunidades Proteicas , Especificidade da Espécie , Amido/metabolismo
6.
Int Heart J ; 59(6): 1261-1265, 2018 Nov 28.
Artigo em Inglês | MEDLINE | ID: mdl-30369573

RESUMO

Interatrial block (IAB) is associated with a multitude of medical conditions. The aim of this retrospective study was to investigate whether CHADS2 (congestive heart failure, hypertension, age ≥ 75 years, diabetes mellitus, prior stroke) score is positively associated with the development of IAB. A total of 1072 patients (men, 555; women, 517; mean age, 61 ± 14 years) were included in the study. P-wave duration was measured manually using a caliper. IAB was defined as a P-wave duration of ≥ 120 ms on a 12-lead electrocardiogram. CHADS2 scores were calculated retrospectively. Among the 1072 patients, the prevalence of IAB was 36.1% (387/1072). In multivariate analysis, increased CHADS2 score (odds ratio [OR], 1.810; 95% confidence interval [CI], 1.577-2.077; P < 0.001), coronary artery disease (OR, 1.536; 95% CI, 1.065-2.216; P = 0.022), and increased left atrial diameter (OR, 1.039; 95% CI, 1.008-1.071; P = 0.013) were independently associated with IAB. The percentages of patients with IAB among those with a CHADS2 score of 0, 1, 2, 3, 4, 5, and 6 were 20.6%, 33.0%, 45.0%, 55.9%, 61.9%, 77.8%, and 100%, respectively (P < 0.001). There was a greater percentage of patients with a CHADS2 score of ≥ 2 with IAB compared with a CHADS2 score of < 2 (26.5% vsrsus 52.0%; P < 0.001). In receiver operating curve (ROC) analysis, CHADS2 score (area under the curve, 0.670; 95% CI, 0.636-0.704; P < 0.001) was predictive of IAB. In conclusion, CHADS2 score was significantly associated with the development of IAB in this study population.


Assuntos
Técnicas de Apoio para a Decisão , Bloqueio Interatrial/diagnóstico , Índice de Gravidade de Doença , Adulto , Idoso , Estudos Transversais , Feminino , Humanos , Bloqueio Interatrial/etiologia , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Razão de Chances , Curva ROC , Estudos Retrospectivos , Fatores de Risco
7.
Yi Chuan ; 39(4): 302-312, 2017 04 20.
Artigo em Inglês | MEDLINE | ID: mdl-28420609

RESUMO

Stomata are small adjustable pores on the surface (epidermis) of land plants that act as a main conduit for gas exchange. They not only play an essential role in photosynthesis of green plants but also exert an important influence on the global carbon and water cycle. There are great differences between monocots and dicots in distribution and morphological structure of the stomata, affecting the species-specific regulation of stomatal development. In this review, we summarize the molecular regulation networks associated with stomatal precursor cell fate determination and the epigenetic mechanisms on regulation of polar cell division. We also outline the stomatal development processes mediated by crosstalk between exogenous and intrinsic signals, and propose a model of multilevel regulation of stomatal development.


Assuntos
Estômatos de Plantas/metabolismo , Transporte Proteico/fisiologia , Transdução de Sinais/fisiologia
8.
Int Heart J ; 57(5): 580-5, 2016 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-27593538

RESUMO

Interatrial block (IAB) is associated with an increased risk of atrial fibrillation (AF). The aim of this retrospective study was to investigate the association of a combination of IAB and the CHADS2 score, an AF-related risk score for ischemic stroke, with new onset AF in patients in sinus rhythm. A total of 1,571 patients (803 males, 768 females; mean age: 58 ± 16 years) were included in this study. IAB was defined as a P-wave duration > 120 ms in the 12-lead electrocardiogram, and a high CHADS2 score as ≥ 2 points. During the mean follow-up period of 4.8 ± 0.7 years, new onset AF occurred in 122 patients (16.1 per 1,000 patient-years). The incidence of new onset AF was 4.0 per 1,000 patient-years in patients with no IAB and a low CHADS2 score, and 44.0 per 1,000 patient-years in patients with IAB and a high CHADS2 score. In multivariate Cox regression analysis, the hazard ratio for IAB and a high CHADS2 score compared with no IAB and a low CHADS2 score was 12.18 (95% confidence interval: 6.22-23.87, P < 0.001), after adjustment for age, sex, coronary artery disease, valvular heart disease, smoking, medications, and echocardiographic parameters. In conclusion, IAB and a high CHADS2 score independently and synergistically predict new onset AF in patients in sinus rhythm, indicating an approximately 12-fold higher risk in patients with both IAB and a high CHADS2 score. Patients meeting these criteria should have more aggressive early intervention to prevent AF.


Assuntos
Fibrilação Atrial/diagnóstico , Fibrilação Atrial/epidemiologia , Eletrocardiografia , Adulto , Idoso , Idoso de 80 Anos ou mais , Função Atrial/fisiologia , Feminino , Humanos , Incidência , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Modelos de Riscos Proporcionais , Estudos Retrospectivos , Medição de Risco , Acidente Vascular Cerebral/etiologia , Acidente Vascular Cerebral/fisiopatologia
9.
Planta ; 242(6): 1391-403, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26253178

RESUMO

MAIN CONCLUSION: Effects of a low aluminum (Al) dose were characterized. The Al supplement inhibited root growth but enhanced leaf growth in maize lines with different Al sensitivities. High levels of Al are phytotoxic especially in acidic soils. The beneficial effects of low Al levels have been reported in some plant species, but not in maize. Maize is relatively more sensitive to Al toxicity than other cereals. Seedlings, at the three leaf stage, of four Chinese maize foundation parent inbred lines with different Al tolerances, were exposed to complete Hoagland's nutrient solution at pH 4.5 supplemented with 48 µM Al(3+) under controlled growth conditions, and then the Al stress (AS) was removed. The leaf and root growth, root cell viability, superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), ions (K(+), Ca(++) and Mg(++)), photosynthetic rate and chlorophyll, protein and malondialdehyde contents in tissues were assayed. In conclusion, a low Al dose inhibits root growth but enhances leaf growth in maize. The Al-promoted leaf growth is likely a result of increased protein synthesis, a lowered Ca(++) level, and the discharge of the growth-inhibitory factors. The Al-promoted leaf growth may be a 'memory' effect caused by the earlier AS in maize. Al causes cell wall rupture, and a loss of K(+), Ca(++) and Mg(++) from root cells. CAT is an auxiliary antioxidant enzyme that works selectively with either SOD or POD against AS-related peroxidation, depending on the maize tissue. CAT is a major antioxidant enzyme responsible for root growth, but SOD is important for leaf growth during AS and after its removal. Our results contribute to understanding how low levels of Al affect maize and Al-resistant mechanisms in maize.


Assuntos
Alumínio/farmacologia , Folhas de Planta/efeitos dos fármacos , Raízes de Plantas/efeitos dos fármacos , Zea mays/efeitos dos fármacos , Antioxidantes/metabolismo , Catalase/metabolismo , Malondialdeído/metabolismo , Micronutrientes/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Folhas de Planta/crescimento & desenvolvimento , Raízes de Plantas/crescimento & desenvolvimento , Superóxido Dismutase/metabolismo , Zea mays/crescimento & desenvolvimento
10.
Plant Cell Environ ; 38(8): 1479-89, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24910171

RESUMO

Response of maize to photoperiods affects adaption of this crop to environments. We characterize the phenotypes of four temperate-adapted maize foundation parents, Huangzao 4, Chang 7-2, Ye 478 and Zheng 58, and two tropically adapted maize foundation parents, M9 and Shuang M9 throughout the growth stage under three constant photoperiod regimes in a daily cycle of 24 h at 28 °C, and analysed expression of 48 photoperiod response-associated genes. Consequently, long photoperiod (LP) repressed development of the tassels of photoperiod-sensitive maize lines at V9 stage, and caused subsequent failure in flowering; failure of photoperiod-sensitive maize lines in flowering under LP was associated with lower expression of flowering-related genes; photoperiod changes could make a marked impact on spatial layout of maize inflorescence. The larger oscillation amplitude of expression of photoperiod-responsive genes occurred in LP-sensitive maize lines. In conclusion, failure in development of tassels at V9 stage under LP is an early indicator for judging photoperiod sensitivity. The adaptation of temperate-adapted maize lines to LP is due to the better coordination of expression among photoperiod-sensing genes instead of the loss of the genes. High photoperiod sensitivity of maize is due to high expression of circadian rhythm-responding genes improperly early in the light.


Assuntos
Fotoperíodo , Zea mays/fisiologia , Flores/genética , Flores/crescimento & desenvolvimento , Flores/fisiologia , Regulação da Expressão Gênica de Plantas , Genes de Plantas , Inflorescência/anatomia & histologia , Fenótipo , Folhas de Planta/genética , Caules de Planta/anatomia & histologia , Zea mays/genética
11.
Crit Rev Biotechnol ; 34(3): 258-68, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23688066

RESUMO

Phenylalanine ammonia lyase (PAL) catalyzes the nonoxidative deamination of l-phenylalanine to form trans-cinnamic acid and a free ammonium ion. It plays a major role in the catabolism of l-phenylalanine. The presence of PAL has been reported in diverse plants, some fungi, Streptomyces and few Cyanobacteria. In the past two decades, PAL has gained considerable significance in several clinical, industrial and biotechnological applications. Since its discovery, much knowledge has been gathered with reference to the enzyme's importance in phenyl propanoid pathway of plants. In contrast, there is little knowledge about microbial PAL. Furthermore, the commercial source of the enzyme has been mainly obtained from the fungi. This study focuses on the recent advances on the physiological role of microbial PAL and the improvements of PAL biotechnological production both from our laboratory and many others as well as the latest advances on the new applications of microbial PAL.


Assuntos
Fenilalanina Amônia-Liase , Bactérias/metabolismo , Fungos/metabolismo , Microbiologia Industrial/métodos , Fenilalanina Amônia-Liase/isolamento & purificação , Fenilalanina Amônia-Liase/metabolismo
12.
Plant Sci ; 346: 112163, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-38880339

RESUMO

A20/AN1 zinc-finger domain-containing genes are very promising candidates in improving plant tolerance to abiotic stresses, but considerably less is known about functions and mechanisms for many of them. In this study, Metip3 (5, and 7), cassava (Manihot esculenta) A20/AN1 genes carrying one A20 domain and one AN1 domain, were functionally characterized at different layers. Metip3 (5, and 7) proteins were all located in the nucleus. No interactions were found between these three proteins. Metip3 (5, and 7)-expressing Arabidopsis was more tolerant to multiple abiotic stresses by Na, Cd, Mn, Al, drought, high temperature, and low temperature. Metip3- and Metip5-expressing Arabidopsis was sensitive to Cu stress, while Metip7-expressing Arabidopsis was insensitive. The H2O2 production significantly decreased in all transgenic Arabidopsis, however, O2·- production significantly decreased in Metip3- and Metip5-expressing Arabidopsis but did not significantly changed in Metip7-expressing Arabidopsis under drought. Metip3 (5, and 7) expression-silenced cassava showed the decreased tolerance to drought and NaCl, presented significant decreases in superoxide dismutase and catalase activities and proline content, and displayed a significant increase in malondialdehyde content under drought. Taken together with transcriptome sequencing analysis, it is suggested that Metip5 gene can not only affect signal transduction related to plant hormone, mitogen activated protein kinases, and starch and sucrose metabolism, DRE-binding transcription factors, and antioxidants, conferring the drought tolerance, but also might deliver the signals from DREB2A INTERACTING PROTEIN1, E3 ubiquitin-protein ligases to proteasome, leading to the drought intolerance. The results are informative not only for further study on evolution of A20/AN1 genes but also for development of climate resilient crops.


Assuntos
Arabidopsis , Manihot , Proteínas de Plantas , Plantas Geneticamente Modificadas , Estresse Fisiológico , Arabidopsis/genética , Arabidopsis/fisiologia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Manihot/genética , Manihot/fisiologia , Estresse Fisiológico/genética , Plantas Geneticamente Modificadas/genética , Regulação da Expressão Gênica de Plantas , Secas , Genes de Plantas , Família Multigênica
13.
Plant Sci ; 327: 111543, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36427558

RESUMO

High air temperature (HAT) and natural soil drought (NSD) have seriously affected crop yield and frequently take place in a HAT-NSD combination. Maize (Zea mays) is an important crop, thermophilic but not heat tolerant. In this study, HAT, NSD, and HAT-NSD effects on maize inbred line Huangzao4 -were characterized. Main findings were as follows: H2O2 and O- accumulated much more in immature young leaves than in mature old leaves under the stresses. Lateral roots were highly distributed near the upper pot mix layers under HAT and near root tips under HAT-NSD. Saccharide accumulated mainly in stressed root caps (RC) and formed a highly accumulated saccharide band at the boundary between RC and meristematic zone. Lignin deposition was in stressed roots under NSD and HAT-NSD. Chloroplasts increased in number and formed a high-density ring around leaf vascular bundles (VB) under HAT and HAT-NSD, and sparsely scattered in the peripheral area of VBs under NSD. The RC cells containing starch granules were most under NAD-HAT but least under HAT. Under NSD and HAT-NSD followed by re-watering, anther number per tassel spikelet reduced to 3. These results provide multiple clues for further distinguishing molecular mechanisms for maize to tolerate these stresses.


Assuntos
Secas , Zea mays , Peróxido de Hidrogênio , Temperatura , Folhas de Planta , Solo
14.
Plant Physiol Biochem ; 194: 394-405, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36481708

RESUMO

The sugar transporter SWEET plays a role in plant growth, carbon allocation, and abiotic stress resistance. We examined the function of SWEET in cassava (Manihot esculenta Crantz) under water and salt stress. Bioinformatics, subcellular localization, yeast deficient complementation, and virus-induced gene silencing (VIGS) were used to examine the function of SWEET in cassava. Twenty-eight MeSWEETs genes were found based on the conserved domain MtN3/saliva of SWEET transporters, two MeSWEET15a/b of them were identified by phylogenetic analysis, which were located on the cell membrane. They transfer sucrose, fructose, glucose, and mannitol from culture media to yeast cells, predominately transferring sucrose via bleeding fluid saps in plant. Leaf sucrose content was increased in MeSWEET15a/b-silenced cassava plants, resulting in changes in carbon distribution, with an increase in starch accumulation in the leaves and a decrease in starch accumulation in the roots. The silencing of MeSWEET15a/b genes led to tolerance to water and salt stress, consistent with a high accumulation of osmolytes, and low lipid membrane peroxidation. Changes in sugar distribution increased the expression of MeTOR and MeE2Fa in pTRV2-MeSWEET15a and pTRV2-MeSWEET15b cassava leaves. MeSWEET15a/b acts as pivotal modulators of sugar distribution and tolerance to water and high salt stress in cassava.


Assuntos
Manihot , Água , Água/metabolismo , Açúcares/metabolismo , Manihot/genética , Manihot/metabolismo , Filogenia , Saccharomyces cerevisiae/metabolismo , Amido/metabolismo , Estresse Salino , Sacarose/metabolismo
15.
Sci Rep ; 13(1): 7375, 2023 05 05.
Artigo em Inglês | MEDLINE | ID: mdl-37147346

RESUMO

The genes enconding proteins containing plasma membrane proteolipid 3 (PMP3) domain are responsive to abiotic stresses, but their functions in maize drought tolerance remain largely unknown. In this study, the transgenic maize lines overexpressing maize ZmPMP3g gene were featured by enhanced drought tolerance; increases in total root length, activities of superoxide dismutase and catalase, and leaf water content; and decreases in leaf water potential, levels of O2-·and H2O2, and malondialdehyde content under drought. Under treatments with foliar spraying with abscisic acid (ABA), drought tolerance of both transgenic line Y7-1 overexpressing ZmPMP3g and wild type Ye478 was enhanced, of which Y7-1 showed an increased endogenous ABA and decreased endogenous gibberellin (GA) 1 (significantly) and GA3 (very slightly but not significantly) and Ye478 had a relatively lower ABA and no changes in GA1 and GA3. ZmPMP3g overexpression in Y7-1 affected the expression of multiple key transcription factor genes in ABA-dependent and -independent drought signaling pathways. These results indicate that ZmPMP3g overexpression plays a role in maize drought tolerance by harmonizing ABA-GA1-GA3 homeostasis/balance, improving root growth, enhancing antioxidant capacity, maintaining membrane lipid integrity, and regulating intracellular osmotic pressure. A working model on ABA-GA-ZmPMP3g was proposed and discussed.


Assuntos
Resistência à Seca , Zea mays , Zea mays/genética , Zea mays/metabolismo , Peróxido de Hidrogênio/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas/genética , Ácido Abscísico/metabolismo , Estresse Fisiológico , Secas , Água/metabolismo , Regulação da Expressão Gênica de Plantas
16.
AoB Plants ; 15(1): plac057, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36654987

RESUMO

The proteins with DNA-binding preference to the consensus DNA sequence (A/T) GATA (A/G) belong to a GATA transcription factor family, with a wide array of biological processes in plants. Cassava (Manihot esculenta) is an important food crop with high production of starch in storage roots. Little was however known about cassava GATA domain-containing genes (MeGATAs). Thirty-six MeGATAs, MeGATA1 to MeGATA36, were found in this study. Some MeGATAs showed a collinear relationship with orthologous genes of Arabidopsis, poplar and potato, rice, maize and sorghum. Eight MeGATA-encoded proteins (MeGATAs) analysed were all localized in the nucleus. Some MeGATAs had potentials of binding ligands and/or enzyme activity. One pair of tandem-duplicated MeGATA17-MeGATA18 and 30 pairs of whole genome-duplicated MeGATAs were found. Fourteen MeGATAs showed low or no expression in the tissues. Nine analysed MeGATAs showed expression responses to abiotic stresses and exogenous phytohormones. Three groups of MeGATA protein interactions were found. Fifty-three miRNAs which can target 18 MeGATAs were identified. Eight MeGATAs were found to target other 292 cassava genes, which were directed to radial pattern formation and phyllome development by gene ontology enrichment, and autophagy by Kyoto Encyclopaedia of Genes and Genomes enrichment. These data suggest that MeGATAs are functional generalists in interactions between cassava growth and development, abiotic stresses and starch metabolism.

17.
Chemosphere ; 286(Pt 1): 131591, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34303053

RESUMO

Drinking water safety cannot be overemphasized. Filamentous fungi have many excellent features for metal removal. Both graphene oxide (GO) and activated carbon (AC) are conventional metal adsorbents, but they are not suitable for large-scale use due to high cost. In this study, a low dosage of conidia (2.0 × 104 conidia/mL) of metal-resistant/adapted filamentous fungus Penicillium janthinillum strain GXCR were co-immobilized with a low dosage of 0.5 mg/L GO or 0.5 mg/L AC by embedding in 2% polyvinyl alcohol (PVA)-3% sodium alginate (SA), generating six types of microbead adsorbents (MBAs) to remove metals from a low concentration of either single metal (100 mg/L) or mixed metals (100 mg/L each) of Pb (II), Fe (III) and Cu (II) in drinking water. Fungus GXCR-containing MBAs had higher specific surface areas (SSAs), better mesoporous structures, and a higher removal rate (85-98.99%) of single or mixed metals. Singl-metal adsorptions of MBAs were almost unaffected by temperature changes. MBAs showed a stable removal rate of 87-94% during four cycles of adsorption-desorption of single metal. Single-metal adsorptions were well described by multiple models of Freundlich isotherm with constant values of 0.21-0.432, Langmuir isotherm with constant values of 0.037-0.17, Pseudo-fist-order, Pseudo-second-order, and intra-particle diffusion (IPD). In conclusion, co-immobilization between GXCR, GO and AC can make metal removal more efficient. Adsorption capacity is increased with SSAs but not in the same proportion. Single-metal adsorptions involve multiple mechanisms of monolayer and multilayer adsorptions, external mass transfer, and IPD. IPD is important but not the only one rate-controlling step for single-metal adsorptions.


Assuntos
Água Potável , Penicillium , Poluentes Químicos da Água , Adsorção , Carvão Vegetal , Compostos Férricos , Grafite , Cinética , Chumbo , Poluentes Químicos da Água/análise
18.
AoB Plants ; 13(5): plab048, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34567492

RESUMO

Flowering in maize (Zea mays) is influenced by photoperiod. The CO, CO-like/COL and TOC1 (CCT) domain protein-encoding genes in maize, ZmCCTs, are particularly important for photoperiod sensitivity. However, little is known about CCT protein-encoding gene number across plant species or among maize inbred lines. Therefore, we analysed CCT protein-encoding gene number across plant species, and characterized ZmCCTs in different inbred lines, including structural variations (SVs), copy number variations (CNVs), expression under stresses, dark-dark (DD) and dark-light (DL) cycles, interaction network and associations with maize quantitative trait loci (QTLs) by referring to the latest v4 genome data of B73. Gene number varied greatly across plant species, more in polyploids than in diploids. The numbers of ZmCCTs identified were 58 in B73, 59 in W22, 48 in Mo17, and 57 in Huangzao4 for temperate maize inbred lines, and 68 in tropical maize inbred line SK. Some ZmCCTs underwent duplications and presented chromosome collinearity. Structural variations and CNVs were found but they had no germplasm specificity. Forty-two ZmCCTs responded to stresses. Expression of 37 ZmCCTs in embryonic leaves during seed germination of maize under DD and DL cycles was roughly divided into five patterns of uphill pattern, downhill-pattern, zigzag-pattern, └-pattern and ⅃-pattern, indicating some of them have a potential to perceive dark and/or dark-light transition. Thirty-three ZmCCTs were co-expressed with 218 other maize genes; and 24 ZmCCTs were associated with known QTLs. The data presented in this study will help inform further functions of ZmCCTs.

19.
Clin Cardiol ; 43(12): 1511-1516, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33002216

RESUMO

BACKGROUND: Although successful ablation of the accessory pathway (AP) eliminates atrial fibrillation (AF) in some of patients with Wolff-Parkinson-White (WPW) syndrome and paroxysmal AF, in other patients it can recur. HYPOTHESIS: Whether adding pulmonary vein isolation (PVI) after successful AP ablation effectively prevents AF recurrence in patients with WPW syndrome is unknown. METHODS: We retrospectively studied 160 patients (102 men, 58 women; mean age, 46 ± 14 years) with WPW syndrome and paroxysmal AF who underwent AP ablation, namely 103 (64.4%) undergoing only AP ablation (AP group) and 57 (35.6%) undergoing AP ablation plus PVI (AP + PVI group). Advanced interatrial block (IAB) was defined as a P-wave duration of >120 ms and biphasic (±) morphology in the inferior leads, using 12-lead electrocardiography (ECG). RESULTS: During the mean follow-up period of 30.9 ± 9.2 months (range, 3-36 months), 22 patients (13.8%) developed AF recurrence. The recurrence rate did not differ in patients in the AP + PVI group and AP group (15.5% vs 10.5%, respectively; P = .373). Univariable and multivariable Cox regression analyses showed that PVI was not associated with the risk of AF recurrence (hazard ratio, 0.66; 95% confidence interval, 0.26-1.68; P = .380). In WPW patients with advanced IAB, the recurrence rate was lower in patients in the AP + PVI group vs the AP group (90% vs 33.3%, respectively; P = .032). CONCLUSIONS: PVI after successful AP ablation significantly reduced the AF recurrence rate in WPW patients with advanced IAB. Screening of a resting 12-lead ECG immediately after AP ablation helps identify patients in whom PVI is beneficial.


Assuntos
Fibrilação Atrial/cirurgia , Fascículo Atrioventricular/fisiopatologia , Ablação por Cateter/métodos , Frequência Cardíaca/fisiologia , Veias Pulmonares/cirurgia , Síndrome de Wolff-Parkinson-White/complicações , Adulto , Fibrilação Atrial/etiologia , Fibrilação Atrial/fisiopatologia , Eletrocardiografia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Recidiva , Estudos Retrospectivos , Resultado do Tratamento , Síndrome de Wolff-Parkinson-White/fisiopatologia , Síndrome de Wolff-Parkinson-White/cirurgia
20.
Physiol Plant ; 136(3): 310-23, 2009 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-19453498

RESUMO

Different defense mechanisms of three spring wheat (Triticum aestivum L.) varieties were studied by withholding watering in well-watered pots to gradually increase water deficit of plants grown in containers. The strategies of plant adaptation were divided into three phases according to the severity of drought: first, a positive defense phase that started from commencement of non-hydraulic root-sourced signals (nHRS) and ended at onset of hydraulic root-sourced signals (HRS)--the plant responded to imminent drought by decreasing stomatal aperture to lessen water loss and no membrane injury occurred. The second defense phase occurred between the onset of HRS and temporary wilting (TW), characterized by enhancement of reactive oxygen species (ROS), marked enzyme activity and increased MDA content. Mild lipid membrane peroxidation came mainly from a dynamic imbalance between free radical production and enzymatic defense reaction, which indicated that injury by ROS had not been completely repaired by increasing enzymatic activity. The third defense phase was from TW to permanent wilting (PW), the synthesis of SOD and CAT during TW could not deal with the collapse of antioxidant enzymes, and SOD and CAT activities began to decrease, which caused the excessive ROS production and thus serious membrane lipid peroxidation. The defense strategies to drought are similar among the varieties, but modern varieties LC8275 and GY602 bred after 1975 had relatively higher defense levels at all three defense phases, which suggest that modern varieties are more resistant than old ones, and artificial selection would lead to a different direction in evolution from natural selection.


Assuntos
Adaptação Fisiológica , Secas , Solo , Triticum/fisiologia , Catalase/metabolismo , Peroxidação de Lipídeos , Raízes de Plantas/fisiologia , Estômatos de Plantas/fisiologia , Transpiração Vegetal/fisiologia , Espécies Reativas de Oxigênio/metabolismo , Superóxido Dismutase/metabolismo , Triticum/enzimologia , Água/fisiologia
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