Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 10 de 10
Filtrar
1.
Plant Direct ; 8(1): e557, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38161730

RESUMO

Proton (H+) release is linked to aluminum (Al)-enhanced organic acids (OAs) excretion from the roots under Al rhizotoxicity in plants. It is well-reported that the Al-enhanced organic acid excretion mechanism is regulated by SENSITIVE TO PROTON RHIZOTOXICITY1 (STOP1), a zinc-finger TF that regulates major Al tolerance genes. However, the mechanism of H+ release linked to OAs excretion under Al stress has not been fully elucidated. Recent physiological and molecular-genetic studies have implicated the involvement of SMALL AUXIN UP RNAs (SAURs) in the activation of plasma membrane H+-ATPases for stress responses in plants. We hypothesized that STOP1 is involved in the regulation of Al-responsive SAURs, which may contribute to the co-secretion of protons and malate under Al stress conditions. In our transcriptome analysis of the roots of the stop1 (sensitive to proton rhizotoxicity1) mutant, we found that STOP1 regulates the transcription of one of the SAURs, namely SAUR55. Furthermore, we observed that the expression of SAUR55 was induced by Al and repressed in the STOP1 T-DNA insertion knockout (KO) mutant (STOP1-KO). Through in silico analysis, we identified a functional STOP1-binding site in the promoter of SAUR55. Subsequent in vitro and in vivo studies confirmed that STOP1 directly binds to the promoter of SAUR55. This suggests that STOP1 directly regulates the expression of SAUR55 under Al stress. We next examined proton release in the rhizosphere and malate excretion in the T-DNA insertion KO mutant of SAUR55 (saur55), in conjunction with STOP1-KO. Both saur55 and STOP1-KO suppressed rhizosphere acidification and malate release under Al stress. Additionally, the root growth of saur55 was sensitive to Al-containing media. In contrast, the overexpressed line of SAUR55 enhanced rhizosphere acidification and malate release, leading to increased Al tolerance. These associations with Al tolerance were also observed in natural variations of Arabidopsis. These findings demonstrate that transcriptional regulation of SAUR55 by STOP1 positively regulates H+ excretion via PM H+-ATPase 2 which enhances Al tolerance by malate secretion from the roots of Arabidopsis. The activation of PM H+-ATPase 2 by SAUR55 was suggested to be due to PP2C.D2/D5 inhibition by interaction on the plasma membrane with its phosphatase. Furthermore, RNAi-suppression of NtSTOP1 in tobacco shows suppression of rhizosphere acidification under Al stress, which was associated with the suppression of SAUR55 orthologs, which are inducible by Al in tobacco. It suggests that transcriptional regulation of Al-inducible SAURs by STOP1 plays a critical role in OAs excretion in several plant species as an Al tolerance mechanism.

2.
J Clin Neuromuscul Dis ; 24(2): 61-67, 2022 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-36409335

RESUMO

BACKGROUND: Ulnar nerve is frequently involved in mononeuropathies of the upper limb. Ulnar neuropathies have been diagnosed conventionally using clinical and electrophysiological findings. Physicians opt for nerve imaging in patients with ambiguous electrophysiological tests to gain additional information, identify etiology and plan management. OBJECTIVES: The aim of this study was to describe the electrophysiological and the magnetic resonance neurography (MRN) findings in patients with nontraumatic ulnar neuropathy. METHODS: All consecutive patients with suspected nontraumatic ulnar mononeuropathy were recruited; clinical assessment and electrophysiological studies (EPSs) were done in all. After EPS, patients with localization of lesion along the ulnar nerve underwent MRN. RESULTS: All 39 patients recruited had clinical findings suggestive of ulnar neuropathy; Electrophysiological confirmation was possible in 36/39 (92.30%) patients. Localization of ulnar nerve lesion to elbow and wrist was possible in 27 (75%) and 9 (25%) patients, respectively. MRN was done in 22 patients; a lesion was identified in 19 of 22 (86.36%) ulnar nerves studied. Thickening and hyperintensity in T2 W/short TI inversion recovery images of ulnar nerve at the level of olecranon, suggesting ulnar neuropathy at elbow, was the commonest (8/22) imaging finding. CONCLUSIONS: MRN acts as a complimentary tool to EPS for evaluating nontraumatic ulnar neuropathy. By identifying the etiology, MRN is likely to modify the management decision.


Assuntos
Imageamento por Ressonância Magnética , Neuropatias Ulnares , Humanos , Centros de Atenção Terciária , Espectroscopia de Ressonância Magnética/efeitos adversos , Imageamento por Ressonância Magnética/métodos , Neuropatias Ulnares/diagnóstico por imagem , Eletrofisiologia
4.
Front Plant Sci ; 12: 774687, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34975956

RESUMO

To elucidate the unknown regulatory mechanisms involved in aluminum (Al)-induced expression of POLYGALACTURONASE-INHIBITING PROTEIN 1 (PGIP1), which is one of the downstream genes of SENSITIVE TO PROTON RHIZOTOXICITY 1 (STOP1) regulating Al-tolerance genes, we conducted a genome-wide association analysis of gene expression levels (eGWAS) of PGIP1 in the shoots under Al stress using 83 Arabidopsis thaliana accessions. The eGWAS, conducted through a mixed linear model, revealed 17 suggestive SNPs across the genome having the association with the expression level variation in PGIP1. The GWAS-detected SNPs were directly located inside transcription factors and other genes involved in stress signaling, which were expressed in response to Al. These candidate genes carried different expression level and amino acid polymorphisms. Among them, three genes encoding NAC domain-containing protein 27 (NAC027), TRX superfamily protein, and R-R-type MYB protein were associated with the suppression of PGIP1 expression in their mutants, and accordingly, the system affected Al tolerance. We also found the involvement of Al-induced endogenous nitric oxide (NO) signaling, which induces NAC027 and R-R-type MYB genes to regulate PGIP1 expression. In this study, we provide genetic evidence that STOP1-independent NO signaling pathway and STOP1-dependent regulation in phosphoinositide (PI) signaling pathway are involved in the regulation of PGIP1 expression under Al stress.

5.
Plant Sci ; 302: 110711, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33288018

RESUMO

To identify unknown regulatory mechanisms leading to aluminium (Al)-induction of the Al tolerance gene ALS3, we conducted an expression genome-wide association study (eGWAS) for ALS3 in the shoots of 95 Arabidopsis thaliana accessions in the presence of Al. The eGWAS was conducted using a mixed linear model with 145,940 genome-wide single nucleotide polymorphisms (SNPs) and the association results were validated using reverse genetics. We found that many SNPs from the eGWAS were associated with genes related to phosphatidylinositol metabolism as well as stress signal transduction, including Ca2+signals, inter-connected in a co-expression network. Of these, PLC9, CDPK32, ANAC071, DIR1, and a hypothetical protein (AT4G10470) possessed amino acid sequence/ gene expression level polymorphisms that were significantly associated with ALS3 expression level variation. Furthermore, T-DNA insertion mutants of PLC9, CDPK32, and ANAC071 suppressed shoot ALS3 expression in the presence of Al. This study clarified the regulatory mechanisms of ALS3 expression in the shoot and provided genetic evidence of the involvement of phosphatidylinositol-derived signal transduction under Al stress.


Assuntos
Transportadores de Cassetes de Ligação de ATP/fisiologia , Alumínio/toxicidade , Proteínas de Arabidopsis/fisiologia , Arabidopsis/genética , Fosfatidilinositóis/metabolismo , Brotos de Planta/metabolismo , Transdução de Sinais , Transportadores de Cassetes de Ligação de ATP/genética , Transportadores de Cassetes de Ligação de ATP/metabolismo , Arabidopsis/metabolismo , Arabidopsis/fisiologia , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Estudo de Associação Genômica Ampla , Malatos/metabolismo , Brotos de Planta/fisiologia , Polimorfismo de Nucleotídeo Único/genética , Estresse Fisiológico , Transcriptoma
6.
Curr Genomics ; 21(3): 168-178, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33071611

RESUMO

Plant-microbe interactions are both symbiotic and antagonistic, and the knowledge of both these interactions is equally important for the progress of agricultural practice and produce. This review gives an insight into the recent advances that have been made in the plant-microbe interaction study in the post-genomic era and the application of those for enhancing agricultural production. Adoption of next-generation sequencing (NGS) and marker assisted selection of resistant genes in plants, equipped with cloning and recombination techniques, has progressed the techniques for the development of resistant plant varieties by leaps and bounds. Genome-wide association studies (GWAS) of both plants and microbes have made the selection of desirable traits in plants and manipulation of the genomes of both plants and microbes effortless and less time-consuming. Stress tolerance in plants has been shown to be accentuated by association of certain microorganisms with the plant, the study and application of the same have helped develop stress-resistant varieties of crops. Beneficial microbes associated with plants are being extensively used for the development of microbial consortia that can be applied directly to the plants or the soil. Next-generation sequencing approaches have made it possible to identify the function of microbes associated in the plant microbiome that are both culturable and non-culturable, thus opening up new doors and possibilities for the use of these huge resources of microbes that can have a potential impact on agriculture.

7.
J Exp Bot ; 70(12): 3329-3342, 2019 06 28.
Artigo em Inglês | MEDLINE | ID: mdl-30977815

RESUMO

To identify the upstream signaling of aluminum-induced malate secretion through aluminum-activated malate transporter 1 (AtALMT1), a pharmacological assay using inhibitors of human signal transduction pathways was performed. Early aluminum-induced transcription of AtALMT1 and other aluminum-responsive genes was significantly suppressed by phosphatidylinositol 4-kinase (PI4K) and phospholipase C (PLC) inhibitors, indicating that the PI4K-PLC metabolic pathway activates early aluminum signaling. Inhibitors of phosphatidylinositol 3-kinase (PI3K) and PI4K reduced aluminum-activated malate transport by AtALMT1, suggesting that both the PI3K and PI4K metabolic pathways regulate this process. These results were validated using T-DNA insertion mutants of PI4K and PI3K-RNAi lines. A human protein kinase inhibitor, putatively inhibiting homologous calcineurin B-like protein-interacting protein kinase and/or Ca-dependent protein kinase in Arabidopsis, suppressed late-phase aluminum-induced expression of AtALMT1, which was concomitant with the induction of an AtALMT1 repressor, WRKY46, and suppression of an AtALMT1 activator, Calmodulin-binding transcription activator 2 (CAMTA2). In addition, a human deubiquitinase inhibitor suppressed aluminum-activated malate transport, suggesting that deubiquitinases can regulate this process. We also found a reduction of aluminum-induced citrate secretion in tobacco by applying inhibitors of PI3K and PI4K. Taken together, our results indicated that phosphatidylinositol metabolism regulates organic acid secretion in plants under aluminum stress.


Assuntos
Alumínio/metabolismo , Proteínas de Arabidopsis/genética , Arabidopsis/metabolismo , Malatos/metabolismo , Transportadores de Ânions Orgânicos/genética , Fosfatidilinositóis/metabolismo , Proteínas de Arabidopsis/metabolismo , Transportadores de Ânions Orgânicos/metabolismo
8.
Prostate Int ; 5(4): 158-161, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29188203

RESUMO

BACKGROUND: Lower urinary tract symptoms (LUTSs) due to benign prostatic hyperplasia (BPH) are common conditions in middle-age or older men. The International Prostate Symptom Score (IPSS) is a useful and validated questionnaire to evaluate LUTS secondary to BPH. Van der Walt et al have developed an alternative questionnaire named the Visual Prostate Symptom Score (VPSS) questionnaire. This study aimed to evaluate the relationship between the VPSS and IPSS in the evaluation of men with LUTSs due to BPH in an Indian population. MATERIALS AND METHODS: This was a prospectively designed study conducted at Sri Sathya Sai Institute of Higher Medical Sciences, Prashanthigram (Anantapur, Andhra Pradesh, India). A total of 121 patients who presented to the urology outpatient department with LUTS due to BPH were enrolled in the study. Patients were followed up at 1-month and 3-month intervals. All patients were given both questionnaires. The correlation test was used to assess the correlation between two symptom scores and various parameters. Observations with a P value < 0.05 were considered statistically significant. RESULTS: There was a statistically significant difference in the number of patients requiring assistance to fill the questionnaires according to their education level. There was a positive correlation between IPSS total score and VPSS total score (r = 0.7235; P < 0.0001), VPSS total score and VPSS quality of life (Qol; r = 0.70753; p < 0.0001), IPSS total versus IPSS Qol (r = 0.65583; P < 0.0001), and IPSS Qol versus VPSS Qol (r = 0.84093; P < 0.0001). A negative correlation was observed between total VPSS with Qmax, total IPSS with Qmax, IPSS total versus Qavg (r = -0.479; P < 0.0001), and VPSS total versus Qavg (r = -0.5; P < 0.0001). All VPSS questions showed statistically significant correlation with the corresponding IPSS questions. CONCLUSION: There is a statistically significant correlation between the VPSS and IPSS and it can be completed by a greater number of patients without assistance.

9.
J Acute Med ; 7(3): 122-124, 2017 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-32995183

RESUMO

Amisulpride is an atypical antipsychotic drug, it helps in alleviation of symptoms of psychotic illnesses. Extrapyramidal features have been reported after taking amisulpride. Neuroleptic malignant syndrome (NMS) with amisulpride is rare, and have been reported earlier. In all the earlier reported cases patient received more than 150 mg of amisulpride. To the best of our knowledge we are reporting a case of NMS with very minimal dose of Amisulpride (50 mg) taken for very short period.

10.
J Stroke Cerebrovasc Dis ; 24(1): 10-6, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25284717

RESUMO

BACKGROUND: India is a subtropical country with clear seasonal variations in weather conditions. Seasonal and circadian variation in occurrence of subtypes of cerebrovascular disease has been of interest in several studies from different countries and climate zones, but discrepant results have made the conclusions unclear. The aim of the present study was to observe the seasonal and circadian variation in the occurrence of stroke and its subtypes among our population. METHODS: This was a cross-sectional observational study based on new cases and past cases of stroke on follow-up, conducted between January 2011 and December 2012 in the Department of Neurology, at the All India Institute of Medical Sciences, New Delhi, India. The date and time of onset of the stroke was recorded. The categorization of months into season was in accordance with the Indian Meteorological Department guidelines. The time of onset was distributed into 6 hourly intervals. Statistical calculations were performed using Stata version 12.1 and SPSS version 20. RESULTS: A total of 583 patients were included for the study. The rate of occurrence of stroke was highest in the late morning 0600-1159 hours (P value <.001) compared with other times of the day, regardless of gender or age for both ischemic and hemorrhagic strokes. It was lowest in late evening (1800-2359 hours) quadrant compared with other quadrants. Although there was no significant difference found by dichotomizing the groups into two 6-month periods, there was an increasing trend in number of patients with stroke during the months November-February. There was no difference in stroke occurrence between the types of stroke or within each type among different seasons with different temperatures. Trial of Org 10172 in Acute Stroke Treatment (TOAST) classification of ischemic strokes also did not show any association with season or circadian rhythm. CONCLUSIONS: There is a significant increase in occurrence of strokes between 0600 and 1159 hours and lowest between 1800-2359 hours. No significant variation in stroke occurrence or subtype for any of the seasons was observed.


Assuntos
Ritmo Circadiano/fisiologia , Estações do Ano , Acidente Vascular Cerebral/classificação , Acidente Vascular Cerebral/epidemiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos Transversais , Feminino , Humanos , Incidência , Índia , Masculino , Pessoa de Meia-Idade
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...