Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 69
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Respir Med Case Rep ; 46: 101941, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38025248

RESUMO

Mycobacterium abscessus subsp. abscessus (MABA) is refractory and sometimes fatal especially in an immunocompromised patient. Also, MABA-associated pneumothorax is an extremely rare complication. We report a case of MABA pulmonary infection complicated pneumothorax treated successfully. A 69-year-old Japanese female with immunosuppressed systemic sclerosis-associated interstitial lung disease experienced left-sided secondary spontaneous pneumothorax. MABA was detected in the pleural effusion and blood culture. Microbial sensitivity test showed the MABA was sensitive to only amikacin, sitafloxacin, and clofazimine. Combination therapy with these antibiotics including azithromycin achieved remission within three weeks. In the treatment of MABA infection, compliance with microbial sensitivity test is crucial.

2.
Sci Rep ; 13(1): 18558, 2023 10 29.
Artigo em Inglês | MEDLINE | ID: mdl-37899362

RESUMO

Coronary artery calcification (CAC) is associated with cardiovascular disease (CVD). CAC might contain calcium oxalate, and a high serum oxalate (SOx) concentration is associated with cardiovascular mortality in dialysis patients. We assessed the associations between SOx and CAC or CVD events in Japanese hemodialysis patients. This cross-sectional and retrospective cohort study was done in 2011. Seventy-seven hemodialysis patients' Agatston CAC score was measured, and serum samples were collected. SOx concentrations were measured in 2021 by using frozen samples. Also, new-onset CVD events in 2011-2021 were retrospectively recorded. The association between SOx concentration and CAC score ≥ 1000, and new-onset CVD events were examined. Median SOx concentration and CAC score were 266.9 (229.5-318.5) µmol/L and 912.5 (123.7-2944), respectively. CAC score ≥ 1000 was associated with SOx [adjusted odds ratio (OR) 1.01, 95% confidence interval (CI), 1.00-1.02]. The number of new-onset CVD events was significantly higher in patients with SOx ≥ median value [hazard ratio (HR) 2.71, 95% CI 1.26-6.16]. By Cox proportional hazard models, new-onset CVD events was associated with SOx ≥ median value (adjusted HR 2.10, 95% CI 0.90-4.91). SOx was associated with CAC score ≥ 1000 and new-onset CVD events in Japanese hemodialysis patients.


Assuntos
Doenças Cardiovasculares , Doença da Artéria Coronariana , Calcificação Vascular , Humanos , Estudos Retrospectivos , Vasos Coronários , Oxalatos , Estudos Transversais , População do Leste Asiático , Angiografia Coronária , Diálise Renal/efeitos adversos , Doença da Artéria Coronariana/complicações , Doenças Cardiovasculares/etiologia , Doenças Cardiovasculares/complicações , Calcificação Vascular/etiologia , Calcificação Vascular/complicações , Fatores de Risco
3.
Front Plant Sci ; 13: 1064628, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36518504

RESUMO

Chitin is a well-known elicitor of disease resistance and its recognition by plants is crucial to perceive fungal infections. Chitin can induce both a local immune response and a systemic disease resistance when provided as a supplement in soils. Unlike local immune responses, it is poorly explored how chitin-induced systemic disease resistance is developed. In this study, we report the systemic induction of disease resistance against the fungal pathogen Bipolaris oryzae by chitin supplementation of soils in rice. The transcriptome analysis uncovered genes related to cell-wall biogenesis, cytokinin signaling, regulation of phosphorylation, and defence priming in the development of chitin-induced systemic response. Alterations of cell-wall composition were observed in leaves of rice plants grown in chitin-supplemented soils, and the disease resistance against B. oryzae was increased in rice leaves treated with a cellulose biosynthesis inhibitor. The disruption of genes for lysin motif (LysM)-containing chitin receptors, OsCERK1 (Chitin elicitor receptor kinase 1) and OsCEBiP (Chitin elicitor-binding protein), compromised chitin-induced systemic disease resistance against B. oryzae and differential expression of chitin-induced genes found in wild-type rice plants. These findings suggest that chitin-induced systemic disease resistance in rice is caused by a perturbation of cell-wall biogenesis in leaves through long-distance signalling after local recognition of chitins by OsCERK1 and OsCEBiP.

4.
Plant Biotechnol (Tokyo) ; 39(2): 119-128, 2022 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-35937538

RESUMO

In rice, the lysin motif (LysM) receptor-like kinase OsCERK1, originally identified as the essential molecule for chitin-triggered immunity, plays a key role in arbuscular mycorrhizal (AM) symbiosis. As we previously reported, although AM colonization was largely repressed at 2 weeks after inoculation (WAI), arbuscules were observed at 5 WAI in oscerk1 mutant. Conversely, most mutant plants that defect the common symbiosis signaling pathway exhibited no arbuscule formation. Concerning the reason for this characteristic phenotype of oscerk1, we speculated that OsRLK10, which is a putative paralog of OsCERK1, may have a redundant function in AM symbiosis. The protein sequences of these two genes are highly conserved and it is estimated that the gene duplication occurred 150 million years ago. Here we demonstrated that OsCERK2/OsRLK10 induced AM colonization and chitin-triggered reactive oxygen species production in oscerk1 knockout mutant as similar to OsCERK1. The oscerk2 mutant showed a slight but significant reduction of AM colonization at 5 WAI, indicating the contribution of OsCERK2 for AM symbiosis. However, the oscerk2;oscerk1 double-knockout mutant produced arbuscules at 5 WAI as similar to the oscerk1 mutant, indicating that the redundancy of OsCERK1 and OsCERK2 did not explain the mycorrhizal colonization in oscerk1 at 5 WAI. These results indicated that OsCERK2 has a potential to regulate both chitin-triggered immunity and AM symbiosis and at least partially contributes to AM symbiosis in rice though the contribution of OsCERK2 appears to be weaker than that of OsCERK1.

5.
BMC Plant Biol ; 21(1): 476, 2021 Oct 19.
Artigo em Inglês | MEDLINE | ID: mdl-34666675

RESUMO

Bacterial canker of tomato (Solanum lycopersicon) caused by the Gram-positive bacterium Clavibacter michiganensis subsp. michiganensis (Cmm) is an economically important disease. To understand the host defense response to Cmm infection, transcriptome sequences in tomato cotyledons were analyzed by RNA-seq. Overall, 1788 and 540 genes were upregulated and downregulated upon infection, respectively. Gene Ontology enrichment analysis revealed that genes involved in the defense response, phosphorylation, and hormone signaling were over-represented by the infection. Induced expression of defense-associated genes suggested that the tomato response to Cmm showed similarities to common plant disease responses. After infection, many resistance gene analogs (RGAs) were transcriptionally upregulated, including the expressions of some receptor-like kinases (RLKs) involved in pattern-triggered immunity. The expressions of WRKYs, NACs, HSFs, and CBP60s encoding transcription factors (TFs) reported to regulate defense-associated genes were induced after infection with Cmm. Tomato genes orthologous to Arabidopsis EDS1, EDS5/SID1, and PAD4/EDS9, which are causal genes of salicylic acid (SA)-deficient mutants, were upregulated after infection with Cmm. Furthermore, Cmm infection drastically stimulated SA accumulation in tomato cotyledons. Genes involved in the phenylalanine ammonia lyase pathway were upregulated, whereas metabolic enzyme gene expression in the isochorismate synthase pathway remained unchanged. Exogenously applied SA suppressed bacterial growth and induced the expression of WRKYs, suggesting that some Cmm-responsive genes are regulated by SA signaling, and SA signaling activation should improve tomato immunity against Cmm.


Assuntos
Interações Hospedeiro-Patógeno , Doenças das Plantas/imunologia , Ácido Salicílico/metabolismo , Solanum lycopersicum/genética , Transcriptoma , Clavibacter/crescimento & desenvolvimento , Clavibacter/fisiologia , Cotilédone/genética , Cotilédone/microbiologia , Cotilédone/fisiologia , Perfilação da Expressão Gênica , Solanum lycopersicum/microbiologia , Solanum lycopersicum/fisiologia , Doenças das Plantas/microbiologia , Imunidade Vegetal , Regulação para Cima
6.
Heart Vessels ; 36(3): 414-423, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33000285

RESUMO

Fibroblast growth factor 23 (FGF23) is a bone-derived hormone that regulates renal phosphate reabsorption and vitamin D synthesis in renal proximal tubules. High circulating FGF23 levels are associated with increased mortality in patients with chronic kidney disease and those on dialysis. Current data also suggest higher circulating levels of FGF23 are associated with cardiovascular mortality, vascular calcification, and left ventricular hypertrophy; however, evidence on the role of FGF23 in patients on dialysis is incomplete, and some of the data, especially those on cardiovascular disease (CVD), are controversial. This study aimed to evaluate factors associated with FGF23 in hemodialysis patients with or without CVD. Randomly selected 76 patients on maintenance hemodialysis at a single hemodialysis center were enrolled. After the exclusion of eight patients with extremely outlying FGF23 levels, 68 patients, including 48 males and 46 patients with a CVD history, were included in the study. The mean age was 64.4 ± 12.1 years, and the mean dialysis duration was 12.7 ± 7.1 years. Dialysis duration, time-averaged concentration of urea (TAC-urea), ultrafiltration rate (UFR), blood pressure during hemodialysis session, laboratory data, and echocardiographic parameters including interventricular septum thickness (IVST), left ventricular mass indices (LVMI), and ejection fraction were included in univariate and multivariate analyses. The median lgFGF23 levels in the overall cohort and in those with and without CVD were 2.14 (interquartile range, IQR - 0.43 to - 4.23), 2.01 (- 0.52 to 4.12), and 2.59 (0.07 to 4.32), respectively, and there was no difference between the patients with and without CVD (p = 0.14). The univariate analysis revealed that FGF23 was significantly associated with age (r = - 0.12, p < 0.01), duration of hemodialysis (r = - 0.11, p < 0.01), TAC-urea (r = 0.29, p = 0.01), UFR (r = 0.26, p = 0.04), alkaline phosphatase (ALP; r = - 0.27, p = 0.03), corrected serum calcium (cCa; r = 0.32, p < 0.01), serum phosphate (iP, r = 0.57, p < 0.01), intact parathyroid hormone (iPTH; r = 0.38, p < 0.01), IVST (r = 0.30, p = 0.01), and LVMI (r = 0.26, p = 0.04). In multivariate regression analysis, FGF23 was significantly associated with cCa (F = 25.6, p < 0.01), iP (F = 22.5, p < 0.01), iPTH (F = 19.2, p < 0.01), ALP (F = 5.34, p = 0.03), and UFR (F = 3.94, p = 0.05). In addition, the univariate analysis after the categorization of patients according to CVD indicated that FGF23 was significantly associated with cCa (r = 0.34, p = 0.02), iP (r = 0.41, p < 0.01), iPTH (r = 0.39, p = 0.01), and TAC-urea (r = 0.45, p < 0.01) in patients with CVD, whereas only IVST (r = 0.53, p = 0.04) was associated with FGF23 in those without CVD. FGF23 levels in hemodialysis patients were extremely high and associated not only with mineral bone disease-related factors but also with UFR. Additionally, dialysis efficacy might be associated with lower FGF23 levels in patients with CVD.


Assuntos
Doenças Cardiovasculares/sangue , Fatores de Crescimento de Fibroblastos/sangue , Falência Renal Crônica/terapia , Ultrafiltração/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores/sangue , Doenças Cardiovasculares/complicações , Estudos Transversais , Feminino , Fator de Crescimento de Fibroblastos 23 , Seguimentos , Humanos , Falência Renal Crônica/sangue , Falência Renal Crônica/complicações , Masculino , Pessoa de Meia-Idade , Prognóstico
7.
Int J Mol Sci ; 21(15)2020 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-32751339

RESUMO

Plant plasma membrane-localized receptors recognize microbe-associated molecular patterns (MAMPs) and activate immune responses via various signaling pathways. Receptor-like cytoplasmic kinases (RLCKs) are considered key signaling factors in plant immunity. BROAD-SPECTRUM RESISTANCE 1 (BSR1), a rice RLCK, plays a significant role in disease resistance. Overexpression of BSR1 confers strong resistance against fungal and bacterial pathogens. Our recent study revealed that MAMP-triggered immune responses are mediated by BSR1 in wild-type rice and are hyperactivated in BSR1-overexpressing rice. It was suggested that hyperactivated immune responses were responsible for the enhancement of broad-spectrum disease resistance; however, this remained to be experimentally validated. In this study, we verified the above hypothesis by disrupting the MAMP-recognition system in BSR1-overexpressing rice. To this end, we knocked out OsCERK1, which encodes a well-characterized MAMP-receptor-like protein kinase. In the background of BSR1 overaccumulation, the knockout of OsCERK1 nearly abolished the enhancement of blast resistance. This finding indicates that overexpressed BSR1-mediated enhancement of disease resistance depends on the MAMP-triggered immune system, corroborating our previously suggested model.


Assuntos
Ascomicetos/genética , Oryza/genética , Doenças das Plantas/genética , Imunidade Vegetal/genética , Proteínas de Plantas/genética , Proteínas Serina-Treonina Quinases/genética , Receptores de Reconhecimento de Padrão/genética , Ascomicetos/crescimento & desenvolvimento , Ascomicetos/patogenicidade , Sequência de Bases , Resistência à Doença , Regulação da Expressão Gênica de Plantas/imunologia , Técnicas de Silenciamento de Genes , Interações Hospedeiro-Patógeno/genética , Interações Hospedeiro-Patógeno/imunologia , Oryza/imunologia , Oryza/microbiologia , Moléculas com Motivos Associados a Patógenos/química , Moléculas com Motivos Associados a Patógenos/metabolismo , Doenças das Plantas/imunologia , Proteínas de Plantas/imunologia , Plantas Geneticamente Modificadas , Proteínas Serina-Treonina Quinases/imunologia , Receptores de Reconhecimento de Padrão/deficiência , Receptores de Reconhecimento de Padrão/imunologia , Transdução de Sinais
8.
CEN Case Rep ; 9(4): 395-403, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32557252

RESUMO

IgG4-related disease preferentially involves the kidney by tubulointerstitial nephritis with IgG4-positive plasma cell filtration and/or membranous glomerulonephritis. We reported the case of a 68-year-old man with IgG4-related tubulointerstitial nephritis combined with antiphospholipase A2 receptor (PLA2R)-related membranous glomerulonephritis, in which distinguishing between idiopathic PLA2R-related and IgG4-related secondary membranous glomerulonephritis was difficult. We diagnosed him as having IgG4-related disease, based on a serum IgG4 level of 170 mg/dL and the presence of IgG4-related parotiditis. On renal biopsy, there was tubulointerstitial nephritis with IgG4-positive plasma cell filtration, which was compatible with IgG4-related disease and membranous glomerulonephritis, with concomitant positive staining for PLA2R on immunofluorescence microscopy. The renal function immediately recovered after steroid treatment, probably because of the improvement in the tubulointerstitial lesions, but his nephrotic syndrome was steroid-resistant. Low-density lipoprotein (LDL) apheresis therapy was effective for membranous glomerulonephritis and increased his serum albumin from 1.4 to 2.8 g/dL. Although IgG4-related kidney disease usually accompanies secondary membranous glomerulonephritis, the positive PLA2R staining suggested a concomitant primary membranous glomerulonephritis. The recent treatment strategy, including LDL apheresis, for primary and secondary membranous glomerulonephritis was discussed briefly in this report.


Assuntos
Remoção de Componentes Sanguíneos/métodos , Glomerulonefrite Membranosa/terapia , Doença Relacionada a Imunoglobulina G4/complicações , Nefrite Intersticial/complicações , Receptores da Fosfolipase A2/metabolismo , Idoso , Biópsia , Glomerulonefrite Membranosa/complicações , Glomerulonefrite Membranosa/metabolismo , Humanos , Imunoglobulina G/sangue , Doença Relacionada a Imunoglobulina G4/diagnóstico , Rim/patologia , Rim/ultraestrutura , Lipoproteínas LDL/metabolismo , Masculino , Microscopia de Fluorescência/métodos , Nefrite Intersticial/imunologia , Nefrite Intersticial/patologia , Síndrome Nefrótica/complicações , Síndrome Nefrótica/terapia , Parotidite/diagnóstico , Parotidite/imunologia , Esteroides/administração & dosagem , Esteroides/uso terapêutico , Resultado do Tratamento
9.
Int J Mol Sci ; 20(22)2019 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-31698708

RESUMO

Plants activate their immune system through intracellular signaling pathways after perceiving microbe-associated molecular patterns (MAMPs). Receptor-like cytoplasmic kinases mediate the intracellular signaling downstream of pattern-recognition receptors. BROAD-SPECTRUM RESISTANCE 1 (BSR1), a rice (Oryza sativa) receptor-like cytoplasmic kinase subfamily-VII protein, contributes to chitin-triggered immune responses. It is valuable for agriculture because its overexpression confers strong disease resistance to fungal and bacterial pathogens. However, it remains unclear how overexpressed BSR1 reinforces plant immunity. Here we analyzed immune responses using rice suspension-cultured cells and sliced leaf blades overexpressing BSR1. BSR1 overexpression enhances MAMP-triggered production of hydrogen peroxide (H2O2) and transcriptional activation of the defense-related gene in cultured cells and leaf strips. Furthermore, the co-cultivation of leaves with conidia of the blast fungus revealed that BSR1 overexpression allowed host plants to produce detectable oxidative bursts against compatible pathogens. BSR1 was also involved in the immune responses triggered by peptidoglycan and lipopolysaccharide. Thus, we concluded that the hyperactivation of MAMP-triggered immune responses confers BSR1-mediated robust resistance to broad-spectrum pathogens.


Assuntos
Resistência à Doença , Oryza/imunologia , Oryza/metabolismo , Doenças das Plantas/imunologia , Proteínas de Plantas/metabolismo , Receptores de Reconhecimento de Padrão/metabolismo , Resistência à Doença/genética , Regulação da Expressão Gênica de Plantas , Genes de Plantas , Peróxido de Hidrogênio/metabolismo , Magnaporthe/fisiologia , Modelos Biológicos , Oryza/genética , Oryza/microbiologia , Peptidoglicano/metabolismo , Doenças das Plantas/genética , Doenças das Plantas/microbiologia , Folhas de Planta/microbiologia , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Explosão Respiratória
11.
Ther Apher Dial ; 22(4): 365-370, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29600583

RESUMO

While vascular calcification is an important factor regulating prognosis in dialysis patients, its components have not been adequately studied. We analyzed in vivo components of calcification in the coronary arteries of dialysis patients using the effective atomic number from dual-energy computed tomography. In dialysis patients (hemodialysis, N = 10; peritoneal dialysis, N = 12), average of median effective atomic number was 13.8 in the hemodialysis group, and 13.7 in the peritoneal dialysis group. No significant differences were seen between groups, with calcium oxalate monohydrate identified as the most common component in each. To confirm the accuracy of this method, we investigated the composition of surgically removed calcified tissues using already established methods. Comparison with the effective atomic number from dual-energy computed tomography showed that the results of calcification analysis were the same. We concluded that calcium oxalate monohydrate might be one of the major components of coronary artery calcification in dialysis patients.


Assuntos
Angiografia por Tomografia Computadorizada/métodos , Doença da Artéria Coronariana/diagnóstico por imagem , Diálise Renal/métodos , Calcificação Vascular/diagnóstico por imagem , Idoso , Idoso de 80 Anos ou mais , Oxalato de Cálcio/metabolismo , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Diálise Peritoneal/métodos , Reprodutibilidade dos Testes
12.
New Phytol ; 217(3): 1042-1049, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-29194635

RESUMO

Plant cell surface receptor-like kinases (RLKs) mediate the signals from microbe-associated molecular patterns (MAMPs) that induce immune responses. Lipopolysaccharide (LPS), the major constituent of the outer membrane of gram-negative bacteria, is a common MAMP perceived by animals and plants; however, the plant receptors/co-receptors are unknown except for LORE, a bulb-type lectin S-domain RLK (B-lectin SD1-RLK) in Arabidopsis. OsCERK1 is a multifunctional RLK in rice that contains lysin motifs (LysMs) and is essential for the perception of chitin, a fungal MAMP, and peptidoglycan, a bacterial MAMP. Here, we analyzed the relevance of OsCERK1 to LPS perception in rice. Using OsCERK1-knockout mutants (oscerk1), we evaluated hydrogen peroxide (H2 O2 ) production and gene expression after LPS treatment. We also examined the LPS response in knockout mutants for the B-lectin SD1-RLK genes in rice and for all LysM-protein genes in Arabidopsis. Compared with wild-type rice cells, LPS responses in oscerk1 cells were mostly diminished. By contrast, rice lines mutated in either of three B-lectin SD1-RLK genes and Arabidopsis lines mutated in the LysM-protein genes responded normally to LPS. From these results, we conclude that OsCERK1 is an LPS receptor/co-receptor and that the LPS perception systems of rice and Arabidopsis are significantly different.


Assuntos
Lipopolissacarídeos/farmacologia , Oryza/imunologia , Imunidade Vegetal/efeitos dos fármacos , Proteínas de Plantas/metabolismo , Arabidopsis/efeitos dos fármacos , Arabidopsis/genética , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Mutação/genética , Oryza/efeitos dos fármacos , Células Vegetais/efeitos dos fármacos , Células Vegetais/metabolismo , Proteínas de Plantas/genética , Espécies Reativas de Oxigênio/metabolismo
13.
New Phytol ; 217(2): 771-783, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-29048113

RESUMO

Rhizoctonia solani is a soil-borne fungus causing sheath blight. In consistent with its necrotrophic life style, no rice cultivars fully resistant to R. solani are known, and agrochemical plant defense activators used for rice blast, which upregulate a phytohormonal salicylic acid (SA)-dependent pathway, are ineffective towards this pathogen. As a result of the unavailability of genetics, the infection process of R. solani remains unclear. We used the model monocotyledonous plants Brachypodium distachyon and rice, and evaluated the effects of phytohormone-induced resistance to R. solani by pharmacological, genetic and microscopic approaches to understand fungal pathogenicity. Pretreatment with SA, but not with plant defense activators used in agriculture, can unexpectedly induce sheath blight resistance in plants. SA treatment inhibits the advancement of R. solani to the point in the infection process in which fungal biomass shows remarkable expansion and specific infection machinery is developed. The involvement of SA in R. solani resistance is demonstrated by SA-deficient NahG transgenic rice and the sheath blight-resistant B. distachyon accessions, Bd3-1 and Gaz-4, which activate SA-dependent signaling on inoculation. Our findings suggest a hemi-biotrophic nature of R. solani, which can be targeted by SA-dependent plant immunity. Furthermore, B. distachyon provides a genetic resource that can confer disease resistance against R. solani to plants.


Assuntos
Brachypodium/microbiologia , Resistência à Doença/efeitos dos fármacos , Oryza/microbiologia , Doenças das Plantas/microbiologia , Imunidade Vegetal/efeitos dos fármacos , Rhizoctonia/fisiologia , Ácido Salicílico/farmacologia , Brachypodium/efeitos dos fármacos , Brachypodium/genética , Brachypodium/crescimento & desenvolvimento , Parede Celular/efeitos dos fármacos , Parede Celular/genética , Resistência à Doença/genética , Ecótipo , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Oryza/efeitos dos fármacos , Doenças das Plantas/genética , Reguladores de Crescimento de Plantas/farmacologia , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Rhizoctonia/efeitos dos fármacos , Rhizoctonia/isolamento & purificação , Transcriptoma/efeitos dos fármacos , Transcriptoma/genética
14.
Plant Direct ; 2(3): e00049, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31245715

RESUMO

Plant roots play important roles in absorbing water and nutrients, and in tolerance against environmental stresses. Previously, we identified a rice root-specific pathogenesis-related protein (RSOsPR10) induced by drought, salt, and wounding. RSOsPR10 expression is strongly induced by jasmonate (JA)/ethylene (ET), but suppressed by salicylic acid (SA). Here, we analyzed the promoter activity of RSOsPR10. Analyses of transgenic rice lines harboring different-length promoter::ß-glucuronidase (GUS) constructs showed that the 3-kb promoter region is indispensable for JA/ET induction, SA repression, and root-specific expression. In the JA-treated 3K-promoter::GUS line, GUS activity was mainly observed at lateral root primordia. Transient expression in roots using a dual luciferase (LUC) assay with different-length promoter::LUC constructs demonstrated that the novel transcription factor OsERF87 induced 3K-promoter::LUC expression through binding to GCC-cis elements. In contrast, the SA-inducible OsWRKY76 transcription factor strongly repressed the JA-inducible and OsERF87-dependent expression of RSOsPR10. RSOsPR10 was expressed at lower levels in OsWRKY76-overexpressing rice, but at higher levels in OsWRKY76-knockout rice, compared with wild type. These results show that two transcription factors, OsERF87 and OsWRKY76, antagonistically regulate RSOsPR10 expression through binding to the same promoter. This mechanism represents a fine-tuning system to sense the balance between JA/ET and SA signaling in plants under environmental stress.

15.
Physiol Plant ; 161(4): 532-544, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28857222

RESUMO

Phytocassanes and momilactones are known as major diterpenoid phytoalexins (DPs), characterized by abundant production and antimicrobial activity, and their biosynthetic genes are clustered in rice genomes. The basic leucine zipper transcription factor OsTGAP1 is known to act as a regulator of the coordinated production of DPs in cultured rice cells, but in planta functions of OsTGAP1 remain largely unknown. Here, we present evidence on the biological function of OsTGAP1 in planta. In wild-type plants, OsTGAP1 is abundantly expressed in roots compared with that in shoots. Moreover, the inductive expression of OsTGAP1 under jasmonic acid (JA) treatment was only observed in a root-specific manner consistent with the JA-inducible expressions of DP biosynthetic genes in roots. In reverse genetic approaches on OsTGAP1-overexpressing and OsTGAP1-knockdown plants, expressions of the biosynthetic genes relevant for DP accumulation were found to be remarkably increased and decreased, respectively. Reporter analysis in planta revealed that OsTGAP1 activated the promoters of OsDXS3 and momilactone biosynthetic gene OsKSL4, presumably through binding to the TGACGT motif. Furthermore, cocultivation experiments with barnyard grass suggested that the allelopathic effect of knockdown and overexpression of OsTGAP1 was significantly changed compared with the controls. These results demonstrate that OsTGAP1 positively regulates DP accumulation via the transcriptional regulation of DP biosynthetic genes in rice roots, and this is indispensable for maintaining allelopathic interactions with paddy weeds by regulating the production of specialized metabolites like momilactones.


Assuntos
Ciclopentanos/farmacologia , Oryza/metabolismo , Oxilipinas/farmacologia , Proteínas de Plantas/metabolismo , Raízes de Plantas/metabolismo , Sesquiterpenos/metabolismo , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Regulação da Expressão Gênica de Plantas/genética , Oryza/efeitos dos fármacos , Raízes de Plantas/efeitos dos fármacos , Fitoalexinas
16.
Biosci Biotechnol Biochem ; 81(8): 1497-1502, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28521637

RESUMO

Broad-Spectrum Resistance 1 (BSR1) encodes a rice receptor-like cytoplasmic kinase, and enhances disease resistance when overexpressed. Rice plants overexpressing BSR1 are highly resistant to diverse pathogens, including rice blast fungus. However, the mechanism responsible for this resistance has not been fully characterized. To analyze the BSR1 function, BSR1-knockout (BSR1-KO) plants were generated using a clustered regularly interspaced short palindromic repeat (CRISPR)/CRISPR-associated protein 9 (Cas9) system. Experiments using suspension-cultured cells revealed that defense responses including H2O2 production (i.e. oxidative burst) and expression of defense-related genes induced by autoclaved conidia of the rice blast fungus significantly decreased in BSR1-KO cells. Furthermore, a treatment with chitin oligomers which function as microbe-associated molecular patterns (MAMPs) of the rice blast fungus resulted in considerably suppressed defense responses in BSR1-KO cells. These results suggest that BSR1 is important for the rice innate immunity triggered by the perception of chitin.


Assuntos
Quitina/imunologia , Resistência à Doença/genética , Regulação da Expressão Gênica de Plantas , Oryza/imunologia , Doenças das Plantas/imunologia , Transdução de Sinais/imunologia , Sequência de Bases , Sistemas CRISPR-Cas , Técnicas de Cultura de Células , Quitina/genética , Técnicas de Inativação de Genes , Peróxido de Hidrogênio/imunologia , Peróxido de Hidrogênio/metabolismo , Magnaporthe/patogenicidade , Magnaporthe/fisiologia , Oryza/genética , Oryza/microbiologia , Células Vegetais/imunologia , Células Vegetais/metabolismo , Células Vegetais/microbiologia , Doenças das Plantas/genética , Doenças das Plantas/microbiologia , Imunidade Vegetal/genética , Proteínas de Plantas/genética , Proteínas de Plantas/imunologia , Plantas Geneticamente Modificadas , Proteínas Serina-Treonina Quinases/genética , Proteínas Serina-Treonina Quinases/imunologia , Transdução de Sinais/genética
17.
PLoS Pathog ; 12(10): e1005921, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27711180

RESUMO

Magnaporthe oryzae, the fungus causing rice blast disease, should contend with host innate immunity to develop invasive hyphae (IH) within living host cells. However, molecular strategies to establish the biotrophic interactions are largely unknown. Here, we report the biological function of a M. oryzae-specific gene, Required-for-Focal-BIC-Formation 1 (RBF1). RBF1 expression was induced in appressoria and IH only when the fungus was inoculated to living plant tissues. Long-term successive imaging of live cell fluorescence revealed that the expression of RBF1 was upregulated each time the fungus crossed a host cell wall. Like other symplastic effector proteins of the rice blast fungus, Rbf1 accumulated in the biotrophic interfacial complex (BIC) and was translocated into the rice cytoplasm. RBF1-knockout mutants (Δrbf1) were severely deficient in their virulence to rice leaves, but were capable of proliferating in abscisic acid-treated or salicylic acid-deficient rice plants. In rice leaves, Δrbf1 inoculation caused necrosis and induced defense-related gene expression, which led to a higher level of diterpenoid phytoalexin accumulation than the wild-type fungus did. Δrbf1 showed unusual differentiation of IH and dispersal of the normally BIC-focused effectors around the short primary hypha and the first bulbous cell. In the Δrbf1-invaded cells, symplastic effectors were still translocated into rice cells but with a lower efficiency. These data indicate that RBF1 is a virulence gene essential for the focal BIC formation, which is critical for the rice blast fungus to suppress host immune responses.


Assuntos
Proteínas Fúngicas/metabolismo , Magnaporthe/patogenicidade , Micoses/microbiologia , Doenças das Plantas/microbiologia , Oryza , Reação em Cadeia da Polimerase , Virulência
18.
Plant Cell Physiol ; 57(11): 2283-2290, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27519312

RESUMO

In legume-specific rhizobial symbiosis, host plants perceive rhizobial signal molecules, Nod factors, by a pair of LysM receptor-like kinases, NFR1/LYK3 and NFR5/NFP, and activate symbiotic responses through the downstream signaling components also required for arbuscular mycorrhizal (AM) symbiosis. Recently, the rice NFR1/LYK3 ortholog, OsCERK1, was shown to play crucial roles for AM symbiosis. On the other hand, the roles of the NFR5/NFP ortholog in rice have not been elucidated, while it has been shown that NFR5/NFP orthologs, Parasponia PaNFR5 and tomato SlRLK10, engage in AM symbiosis. OsCERK1 also triggers immune responses in combination with a receptor partner, OsCEBiP, against fungal or bacterial infection, thus regulating opposite responses against symbiotic and pathogenic microbes. However, it has not been elucidated how OsCERK1 switches these opposite functions. Here, we analyzed the function of the rice NFR5/NFP ortholog, OsNFR5/OsRLK2, as a possible candidate of the OsCERK1 partner for symbiotic signaling. Inoculation of AM fungi induced the expression of OsNFR5 in the rice root, and the chimeric receptor consisting of the extracellular domain of LjNFR5 and the intracellular domain of OsNFR5 complemented the Ljnfr5 mutant for rhizobial symbiosis, indicating that the intracellular kinase domain of OsNFR5 could activate symbiotic signaling in Lotus japonicus. Although these data suggested the possible involvement of OsNFR5 in AM symbiosis, osnfr5 knockout mutants were colonized by AM fungi similar to the wild-type rice. These observations suggested several possibilities including the presence of functionally redundant genes other than OsNFR5 or involvement of novel ligands, which do not require OsNFR5 for recognition.


Assuntos
Micorrizas/fisiologia , Oryza/enzimologia , Oryza/microbiologia , Proteínas de Plantas/metabolismo , Proteínas Quinases/metabolismo , Simbiose , Regulação da Expressão Gênica de Plantas , Técnicas de Inativação de Genes , Genes de Plantas , Teste de Complementação Genética , Lotus/metabolismo , Mutação/genética , Oryza/genética , Fenótipo , Filogenia , Proteínas de Plantas/genética , Nodulação/genética , Proteínas Quinases/genética , Multimerização Proteica , Homologia de Sequência de Aminoácidos , Simbiose/genética
19.
Plant Mol Biol ; 91(1-2): 81-95, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-26879413

RESUMO

Membrane trafficking plays pivotal roles in many cellular processes including plant immunity. Here, we report the characterization of OsVAMP714, an intracellular SNARE protein, focusing on its role in resistance to rice blast disease caused by the fungal pathogen Magnaporthe oryzae. Disease resistance tests using OsVAMP714 knockdown and overexpressing rice plants demonstrated the involvement of OsVAMP714 in blast resistance. The overexpression of OsVAMP7111, whose product is highly homologous to OsVAMP714, did not enhance blast resistance to rice, implying a potential specificity of OsVAMP714 to blast resistance. OsVAMP714 was localized to the chloroplast in mesophyll cells and to the cellular periphery in epidermal cells of transgenic rice plant leaves. We showed that chloroplast localization is critical for the normal OsVAMP714 functioning in blast resistance by analyzing the rice plants overexpressing OsVAMP714 mutants whose products did not localize in the chloroplast. We also found that OsVAMP714 was located in the vacuolar membrane surrounding the invasive hyphae of M. oryzae. Furthermore, we showed that OsVAMP714 overexpression promotes leaf sheath elongation and that the first 19 amino acids, which are highly conserved between animal and plant VAMP7 proteins, are crucial for normal rice plant growths. Our studies imply that the OsVAMP714-mediated trafficking pathway plays an important role in rice blast resistance as well as in the vegetative growth of rice.


Assuntos
Regulação da Expressão Gênica de Plantas/fisiologia , Oryza/metabolismo , Doenças das Plantas/microbiologia , Proteínas de Plantas/metabolismo , Transporte Proteico/fisiologia , Proteínas R-SNARE/metabolismo , Membrana Celular , Cloroplastos/fisiologia , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Predisposição Genética para Doença , Doenças das Plantas/genética , Doenças das Plantas/imunologia , Proteínas de Plantas/genética , Proteínas R-SNARE/genética , Ácido Salicílico/farmacologia
20.
J Obstet Gynaecol Res ; 42(3): 331-5, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26628290

RESUMO

We describe the course of pregnancy in a 27-year-old woman with homozygous autosomal recessive Alport syndrome. Genetic analysis revealed a homozygous COL4A4 mutation in exon 36 (c.3307G > A) with p.G1102R inherited from her parents (who were parallel cousins) 1 year before conception. Before pregnancy, the patient's renal function and blood pressure were normal, and her urinary protein excretion was below 2 g/day. The pregnancy course was uneventful in the first and second trimesters. She was detected to have nephrotic-range proteinuria during the third trimester, but was observed closely on an outpatient basis without any medications, as her general condition was good, her renal function and blood pressure remained stable, and the fetal well-being was maintained. At 39(+0) weeks of pregnancy, she vaginally gave birth to an appropriate-birthweight infant and her urinary protein excretion returned to pre-pregnancy level. This is the first report of pregnancy in a patient with autosomal recessive Alport syndrome with good obstetric and nephrological outcomes in the absence of any treatment or hospitalization.


Assuntos
Nefrite Hereditária , Complicações na Gravidez , Adulto , Feminino , Humanos , Gravidez , Resultado da Gravidez
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...