RESUMO
The plasma membrane-localized phytosulfokine receptor-like protein TaRLK-6A, interacting with TaSERK1, positively regulates the expression of defense-related genes in wheat, consequently promotes host resistance to Fusarium crown rot.
Assuntos
Fusarium , Triticum , Triticum/genética , Fusarium/fisiologia , Doenças das Plantas/genéticaRESUMO
Sharp eyespot and Fusarium crown rot, mainly caused by soil-borne fungi Rhizoctonia cerealis and Fusarium pseudograminearum, are destructive diseases of major cereal crops including wheat (Triticum aestivum). However, the mechanisms underlying wheat-resistant responses to the two pathogens are largely elusive. In this study, we performed a genome-wide analysis of wall-associated kinase (WAK) family in wheat. As a result, a total of 140 TaWAK (not TaWAKL) candidate genes were identified from the wheat genome, each of which contains an N-terminal signal peptide, a galacturonan binding domain, an EGF-like domain, a calcium binding EGF domain (EGF-Ca), a transmembrane domain, and an intracellular Serine/Threonine protein kinase domain. By analyzing the RNA-sequencing data of wheat inoculated with R. cerealis and F. pseudograminearum, we found that transcript abundance of TaWAK-5D600 (TraesCS5D02G268600) on chromosome 5D was significantly upregulated, and that its upregulated transcript levels in response to both pathogens were higher compared with other TaWAK genes. Importantly, knock-down of TaWAK-5D600 transcript impaired wheat resistance against the fungal pathogens R. cerealis and F. pseudograminearum, and significantly repressed expression of defense-related genes in wheat, TaSERK1, TaMPK3, TaPR1, TaChitinase3, and TaChitinase4. Thus, this study proposes TaWAK-5D600 as a promising gene for improving wheat broad resistance to sharp eyespot and Fusarium crown rot (FCR) in wheat.
Assuntos
Fusarium , Triticum , Triticum/genética , Fusarium/genética , Fator de Crescimento Epidérmico/metabolismo , Cromossomos , Sequência de Bases , Doenças das Plantas/microbiologiaRESUMO
Fusarium pseudograminearum is a major pathogen for the destructive disease Fusarium crown rot (FCR) of wheat (Triticum aestivum). The cytosolic Acetoacetyl-CoA thiolase II (AACT) is the first catalytic enzyme in the mevalonate pathway that biosynthesizes isoprenoids in plants. However, there has been no investigation of wheat cytosolic AACT genes in defense against pathogens including Fusarium pseudograminearum. Herein, we identified a cytosolic AACT-encoding gene from wheat, named TaAACT1, and demonstrated its positively regulatory role in the wheat defense response to F. pseudograminearum. One haplotype of TaAACT1 in analyzed wheat genotypes was associated with wheat resistance to FCR. The TaAACT1 transcript level was elevated after F. pseudograminearum infection, and was higher in FCR-resistant wheat genotypes than in susceptible wheat genotypes. Functional analysis indicated that knock down of TaAACT1 impaired resistance against F. pseudograminearum and reduced the expression of downstream defense genes in wheat. TaAACT1 protein was verified to localize in the cytosol of wheat cells. TaAACT1 and its modulated defense genes were rapidly responsive to exogenous jasmonate treatment. Collectively, TaAACT1 contributes to resistance to F. pseudograminearum through upregulating the expression of defense genes in wheat. This study sheds new light on the molecular mechanisms underlying wheat defense against FCR.
Assuntos
Fusarium , Fusarium/genética , Triticum/genética , Doenças das Plantas/genética , GenótipoRESUMO
Seed dormancy is an important agronomic trait in crops, and plants with low dormancy are prone to preharvest sprouting (PHS) under high-temperature and humid conditions. In this study, we report that the GATA transcription factor TaGATA1 is a positive regulator of seed dormancy by regulating TaABI5 expression in wheat. Our results demonstrate that TaGATA1 overexpression significantly enhances seed dormancy and increases resistance to PHS in wheat. Gene expression patterns, abscisic acid (ABA) response assay, and transcriptome analysis all indicate that TaGATA1 functions through the ABA signaling pathway. The transcript abundance of TaABI5, an essential regulator in the ABA signaling pathway, is significantly elevated in plants overexpressing TaGATA1. Chromatin immunoprecipitation assay (ChIP) and transient expression analysis showed that TaGATA1 binds to the GATA motifs at the promoter of TaABI5 and induces its expression. We also demonstrate that TaGATA1 physically interacts with the putative demethylase TaELF6-A1, the wheat orthologue of Arabidopsis ELF6. ChIP-qPCR analysis showed that H3K27me3 levels significantly decline at the TaABI5 promoter in the TaGATA1-overexpression wheat line and that transient expression of TaELF6-A1 reduces methylation levels at the TaABI5 promoter, increasing TaABI5 expression. These findings reveal a new transcription module, including TaGATA1-TaELF6-A1-TaABI5, which contributes to seed dormancy through the ABA signaling pathway and epigenetic reprogramming at the target site. TaGATA1 could be a candidate gene for improving PHS resistance.
Assuntos
Fatores de Transcrição GATA , Triticum , Ácido Abscísico/metabolismo , Arabidopsis/metabolismo , Proteínas de Arabidopsis/metabolismo , Fatores de Transcrição GATA/genética , Regulação da Expressão Gênica de Plantas , Germinação , Dormência de Plantas/genética , Sementes/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Triticum/genética , Triticum/metabolismo , Proteínas de Plantas/genéticaRESUMO
STAUROSPORINE AND TEMPERATURE SENSITIVE3 (STT3) is a catalytic subunit of oligosaccharyltransferase, which is important for asparagine-linked glycosylation. Sharp eyespot, caused by the necrotrophic fungal pathogen Rhizoctonia cerealis, is a devastating disease of bread wheat. However, the molecular mechanisms underlying wheat defense against R. cerealis are still largely unclear. In this study, we identified TaSTT3a and TaSTT3b, two STT3 subunit genes from wheat and reported their functional roles in wheat defense against R. cerealis and increasing grain weight. The transcript abundance of TaSTT3b-2B was associated with the degree of wheat resistance to R. cerealis and induced by both R. cerealis and exogenous jasmonic acid (JA). Overexpression of TaSTT3b-2B significantly enhanced resistance to R. cerealis, grain weight, and JA content in transgenic wheat subjected to R. cerealis stress, while silencing of TaSTT3b-2B compromised resistance of wheat to R. cerealis. Transcriptomic analysis showed that TaSTT3b-2B affected the expression of a series of defense-related genes and JA biosynthesis-related genes, as well as genes coding starch synthase and sucrose synthase. Application of exogenous JA elevated expression levels of the abovementioned defense- and grain weight-related genes, and rescuing the resistance of TaSTT3b-2B-silenced wheat to R. cerealis, while pretreatment with sodium diethyldithiocarbamate, an inhibitor of JA synthesis, attenuated the TaSTT3b-2B-mediated resistance to R. cerealis, suggesting that TaSTT3b-2B played critical roles in regulating R. cerealis resistance and grain weight via JA biosynthesis. Altogether, this study reveals new functional roles of TaSTT3b-2B in regulating plant innate immunity and grain weight, and illustrates its potential application value for wheat molecular breeding.
Assuntos
Resistência à Doença , Triticum , Resistência à Doença/genética , Grão Comestível/genética , Grão Comestível/metabolismo , Regulação da Expressão Gênica de Plantas , Doenças das Plantas/microbiologia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Rhizoctonia , Triticum/metabolismoRESUMO
BACKGROUND: The psoas major (PM) can support the lumbar spine and plays an important role in lumbar movement and maintaining lumbar curvature. PURPOSE: To analyze morphological changes of PM and its relation with the severity of adolescent idiopathic scoliosis (AIS). MATERIAL AND METHODS: The study was conducted on patients with AIS (age range = 10-18 years) with primary lumbar scoliosis. The cross-sectional area (CSA) of the PM at the L1-L5 levels were measured. The CSA of the PM in patients with AIS was compared with the average CSA of the PM in age-matched controls. The difference in PM at the apical vertebrae level was compared with the Cobb angle to determine the association between PM imbalance and severity of scoliosis. RESULTS: The CSA of the PM was larger on the concave side than the convex side at the apical vertebrae level and other lumber levels. Patients with a larger Cobb angle had statistically higher PM imbalance at the apical vertebrae level. The CSA of the PM on both the concave and convex sides of patients with AIS were larger than the average CSA of controls aged 16-18 years; however, there was no significant difference between patients with AIS and controls aged 10-15 years. CONCLUSION: There is a significant PM imbalance in patients with AIS before skeletal maturity, and the imbalance is related to the severity of scoliosis. The morphology of PM changed with the progression of scoliosis.
Assuntos
Músculos Psoas/diagnóstico por imagem , Escoliose/diagnóstico por imagem , Adolescente , Fatores Etários , Criança , Feminino , Humanos , Região Lombossacral , Imageamento por Ressonância Magnética , Masculino , Radiografia , Estudos Retrospectivos , Índice de Gravidade de DoençaRESUMO
Sharp eyespot, caused by necrotrophic fungus Rhizoctonia cerealis, is a serious fungal disease in wheat (Triticum aestivum). Certain wall-associated receptor kinases (WAK) mediate resistance to diseases caused by biotrophic/hemibiotrophic pathogens in several plant species. Yet, none of wheat WAK genes with positive effect on the innate immune responses to R. cerealis has been reported. In this study, we identified a WAK gene TaWAK7D, located on chromosome 7D, and showed its positive regulatory role in the defense response to R. cerealis infection in wheat. RNA-seq and qRT-PCR analyses showed that TaWAK7D transcript abundance was elevated in wheat after R. cerealis inoculation and the induction in the stem was the highest among the tested organs. Additionally, TaWAK7D transcript levels were significantly elevated by pectin and chitin treatments. The knock-down of TaWAK7D transcript impaired resistance to R. cerealis and repressed the expression of five pathogenesis-related genes in wheat. The green fluorescent protein signal distribution assays indicated that TaWAK7D localized on the plasma membrane in wheat protoplasts. Thus, TaWAK7D, which is induced by R. cerealis, pectin and chitin stimuli, positively participates in defense responses to R. cerealis through modulating the expression of several pathogenesis-related genes in wheat.
Assuntos
Resistência à Doença , Regulação Enzimológica da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Doenças das Plantas/microbiologia , Proteínas de Plantas , Proteínas Quinases , Rhizoctonia/crescimento & desenvolvimento , Triticum , Proteínas de Plantas/biossíntese , Proteínas de Plantas/genética , Proteínas Quinases/biossíntese , Proteínas Quinases/genética , Triticum/enzimologia , Triticum/genética , Triticum/microbiologiaRESUMO
In the original article, there was a mistake in Figure 8 as published [...].
RESUMO
Fusarium head blight (FHB) and sharp eyespot are important diseases of the cereal plants, including bread wheat (Triticum aestivum) and barley. Both diseases are predominately caused by the pathogenic fungi, Fusarium graminearum and Rhizoctonia cerealis. The roles of the wheat-wall-associated kinases (WAKs) in defense against both F. graminearum and R. cerealis have remained largely unknown. This research reports the identification of TaWAK2A-800, a wheat WAK-coding gene located on chromosome 2A, and its functional roles in wheat resistance responses to FHB and sharp eyespot. TaWAK2A-800 transcript abundance was elevated by the early infection of R. cerealis and F. graminearum, or treatment with exogenous chitin. The gene transcript seemed to correspond to the resistance of wheat. Further functional analyses showed that silencing TaWAK2A-800 compromised the resistance of wheat to both FHB (F. graminearum) and sharp eyespot (R. cerealis). Moreover, the silencing reduced the expression levels of six defense-related genes, including the chitin-triggering immune pathway-marker genes, TaCERK1, TaRLCK1B, and TaMPK3. Summarily, TaWAK2A-800 participates positively in the resistance responses to both F. graminearum and R. cerealis, possibly through a chitin-induced pathway in wheat. TaWAK2A-800 will be useful for breeding wheat varieties with resistance to both FHB and sharp eyespot.
Assuntos
Basidiomycota/metabolismo , Resistência à Doença/genética , Fusarium/metabolismo , Doenças das Plantas/microbiologia , Proteínas Quinases/metabolismo , Triticum/microbiologia , Parede Celular/enzimologia , Grão Comestível/microbiologia , Genoma de Planta/genética , Imunidade Inata/genética , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Doenças das Plantas/prevenção & controle , Proteínas Quinases/genéticaRESUMO
Wheat (Triticum aestivum) is essential for global food security. Rhizoctonia cerealis is the causal pathogen of sharp eyespot, an important disease of wheat. GATA proteins in model plants have been implicated in growth and development; however, little is known about their roles in immunity. Here, we report a defence role for a wheat LLM-domain-containing B-GATA transcription factor, TaGATA1, against R. cerealis infection and explore the underlying mechanism. Through transcriptomic analysis, TaGATA1 was identified to be more highly expressed in resistant wheat genotypes than in susceptible wheat genotypes. TaGATA1 was located on chromosome 3B and had two homoeologous genes on chromosomes 3A and 3D. TaGATA1 was found to be localized in the nucleus, possessed transcriptional activation activity, and bound to GATA-core cis-elements. TaGATA1 overexpression significantly enhanced resistance of transgenic wheat to R. cerealis, whereas silencing of TaGATA1 suppressed the resistance. Quantitative reverse transcription-PCR and ChIP-qPCR results indicated that TaGATA1 directly bound to and activated certain defence genes in host immune response to R. cerealis. Collectively, TaGATA1 positively regulates immune responses to R. cerealis through activating expression of defence genes in wheat. This study reveals a new function of plant GATAs in immunity and provides a candidate gene for improving crop resistance to R. cerealis.
Assuntos
Basidiomycota/fisiologia , Fator de Transcrição GATA1/genética , Doenças das Plantas/imunologia , Imunidade Vegetal/genética , Proteínas de Plantas/genética , Triticum/genética , Sequência de Aminoácidos , Resistência à Doença/imunologia , Fator de Transcrição GATA1/química , Fator de Transcrição GATA1/metabolismo , Proteínas de Plantas/química , Proteínas de Plantas/metabolismo , Triticum/metabolismo , Triticum/microbiologiaRESUMO
OBJECTIVE: To differentiate supratentorial single brain metastasis (MET) from glioblastoma (GBM) by using radiomic features derived from the peri-enhancing oedema region and multiple classifiers. METHODS: One hundred and twenty single brain METs and GBMs were retrospectively reviewed and then randomly divided into a training data set (70%) and validation data set (30%). Quantitative radiomic features of each case were extracted from the peri-enhancing oedema region of conventional MR images. After feature selection, five classifiers were built. Additionally, the combined use of the classifiers was studied. Accuracy, sensitivity, and specificity were used to evaluate the classification performance. RESULTS: A total of 321 features were extracted, and 3 features were selected for each case. The 5 classifiers showed an accuracy of 0.70 to 0.76, sensitivity of 0.57 to 0.98, and specificity of 0.43 to 0.93 for the training data set, with an accuracy of 0.56 to 0.64, sensitivity of 0.39 to 0.78, and specificity of 0.50 to 0.89 for the validation data set. When combining the classifiers, the classification performance differed according to the combined mode and the agreement pattern of classifiers, and the greatest benefit was obtained when all the classifiers reached agreement using the same weight and simple majority vote method. CONCLUSIONS: Three features derived from the peri-enhancing oedema region had moderate value in differentiating supratentorial single brain MET from GBM with five single classifiers. Combined use of classifiers, like multi-disciplinary team (MDT) consultation, could confer extra benefits, especially for those cases when all classifiers reach agreement. KEY POINTS: ⢠Radiomics provides a way to differentiate single brain MET between GBM by using conventional MR images. ⢠The results of classifiers or algorithms themselves are also data, the transformation of the primary data. ⢠Like MDT consultation, the combined use of multiple classifiers may confer extra benefits.
Assuntos
Edema Encefálico/diagnóstico por imagem , Neoplasias Encefálicas/diagnóstico por imagem , Neoplasias Encefálicas/secundário , Glioblastoma/diagnóstico por imagem , Aumento da Imagem/métodos , Neoplasias Pulmonares/patologia , Imageamento por Ressonância Magnética/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Algoritmos , Confiabilidade dos Dados , Diagnóstico Diferencial , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Período Pré-Operatório , Distribuição Aleatória , Estudos Retrospectivos , Sensibilidade e Especificidade , Adulto JovemRESUMO
Rhizoctonia cerealis is the causal pathogen of the devastating disease, sharp eyespot, of the important crop wheat (Triticum aestivum L.). In phytopathogenic fungi, several M36 metalloproteases have been implicated in virulence, but pathogenesis roles of M35 family metalloproteases are largely unknown. Here, we identified four M35 family metalloproteases from R. cerealis genome, designated RcMEP2-RcMEP5, measured their transcriptional profiles, and investigated RcMEP2 function. RcMEP2-RcMEP5 are predicted as secreted metalloproteases since each protein sequence contains a signal peptide and an M35 domain that includes two characteristic motifs HEXXE and GTXDXXYG. Transcription levels of RcMEP2-RcMEP5 markedly elevated during the fungus infection to wheat, among which RcMEP2 expressed with the highest level. Functional dissection indicated that RcMEP2 and its M35 domain could trigger H2O2 rapidly-excessive accumulation, induce cell death, and inhibit expression of host chitinases. This consequently enhanced the susceptibility of wheat to R. cerealis and the predicated signal peptide of RcMEP2 functions required for secretion and cell death-induction. These results demonstrate that RcMEP2 is a virulence factor and that its M35 domain and signal peptide are necessary for the virulence role of RcMEP2. This study facilitates a better understanding of the pathogenesis mechanism of metalloproteases in phytopathogens including R. cerealis.
Assuntos
Proteínas de Transporte de Cátions/genética , Proteínas Fúngicas/genética , Metaloproteases/genética , Doenças das Plantas/genética , Doenças das Plantas/microbiologia , Rhizoctonia/fisiologia , Triticum/microbiologia , Genoma Fúngico , Interações Hospedeiro-Patógeno , Peróxido de Hidrogênio/metabolismo , Família Multigênica , Fenótipo , Filogenia , Fatores de Virulência/genéticaRESUMO
OBJECTIVE: To differentiate brain pilocytic astrocytoma (PA) from glioblastoma (GBM) using contrast-enhanced magnetic resonance imaging (MRI) quantitative radiomic features by a decision tree model. METHODS: Sixty-six patients from two centres (PA, n = 31; GBM, n = 35) were randomly divided into training and validation data sets (about 2:1). Quantitative radiomic features of the tumours were extracted from contrast-enhanced MR images. A subset of features was selected by feature stability and Boruta algorithm. The selected features were used to build a decision tree model. Predictive accuracy, sensitivity and specificity were used to assess model performance. The classification outcome of the model was combined with tumour location, age and gender features, and multivariable logistic regression analysis and permutation test using the entire data set were performed to further evaluate the decision tree model. RESULTS: A total of 271 radiomic features were successfully extracted for each tumour. Twelve features were selected as input variables to build the decision tree model. Two features S(1, -1) Entropy and S(2, -2) SumAverg were finally included in the model. The model showed an accuracy, sensitivity and specificity of 0.87, 0.90 and 0.83 for the training data set and 0.86, 0.80 and 0.91 for the validation data set. The classification outcome of the model related to the actual tumour types and did not rely on the other three features (p < 0.001). CONCLUSIONS: A decision tree model with two features derived from the contrast-enhanced MR images performed well in differentiating PA from GBM. KEY POINTS: ⢠MRI findings of PA and GBM are sometimes very similar. ⢠Radiomics provides much more quantitative information about tumours. ⢠Radiomic features can help to distinguish PA from GBM.
Assuntos
Algoritmos , Astrocitoma/diagnóstico , Neoplasias Encefálicas/diagnóstico , Encéfalo/patologia , Árvores de Decisões , Glioblastoma/diagnóstico , Imageamento por Ressonância Magnética/métodos , Adolescente , Adulto , Idoso , Criança , Diagnóstico Diferencial , Feminino , Humanos , Aumento da Imagem , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Adulto JovemRESUMO
Pancreatic cancer is a concealed and highly malignant tumor, and its early diagnosis plays an increasingly weighty role during the course of cancer treatment. In this study, we developed a polymeric magnetic resonance imaging (MRI) nanoplatform for MRI contrast agents. To improve tumor-targeting delivery of MRI contrast agents, we employed a pancreatic cancer targeting CKAAKN peptide to prepare a peptide-functionalized amphiphilic hyaluronic acid-vitamin E succinate polymer (CKAAKN-HA-VES) for delivering ultra-small superparamagnetic iron oxide (USPIO), namely, CKAAKN-HA-VES@USPIO. With the modification of the CKAAKN peptide, CKAAKN-HA-VES@USPIO could specifically internalize into CKAAKN-positive BxPC-3 cells. The CKAAKN-HA-VES@USPIO nanoparticles presented a more specific accumulation into pancreatic cancer cells than normal pancreatic cells, and an obvious decrease in signal intensity was observed in CKAAKN-positive BxPC-3 cells, compared with CKAAKN-negative HPDE6-C7 cells and non-targeting HA-VES@USPIO nanoparticles. The results demonstrated that our polymeric MRI nanoplatform could selectively internalize into CKAAKN-positive pancreatic cancer cells by the specific binding of CKAAKN peptide with pancreatic cancer cell membrane receptors, which provided a novel polymeric MRI contrast agent with high specificity for pancreatic cancer diagnosis, and makes it a very promising candidate for magnetic resonance imaging contrast enhancement.
Assuntos
Biopolímeros/química , Meios de Contraste/química , Nanopartículas de Magnetita/química , Peptídeos/química , Nanomedicina Teranóstica , Linhagem Celular Tumoral , Sobrevivência Celular , Técnicas de Química Sintética , Humanos , Imageamento por Ressonância Magnética/métodos , Nanopartículas de Magnetita/ultraestrutura , Estrutura Molecular , Neoplasias Pancreáticas/diagnóstico por imagem , Nanomedicina Teranóstica/métodosRESUMO
The necrotrophic fungus Rhizoctonia cerealis is the major pathogen causing sharp eyespot disease in wheat (Triticum aestivum). Nucleotide-binding leucine-rich repeat (NB-LRR) proteins often mediate plant disease resistance to biotrophic pathogens. Little is known about the role of NB-LRR genes involved in wheat response to R. cerealis. In this study, a wheat NB-LRR gene, named TaRCR1, was identified in response to R. cerealis infection using Artificial Neural Network analysis based on comparative transcriptomics and its defence role was characterized. The transcriptional level of TaRCR1 was enhanced after R. cerealis inoculation and associated with the resistance level of wheat. TaRCR1 was located on wheat chromosome 3BS and encoded an NB-LRR protein that was consisting of a coiled-coil domain, an NB-ARC domain and 13 imperfect leucine-rich repeats. TaRCR1 was localized in both the cytoplasm and the nucleus. Silencing of TaRCR1 impaired wheat resistance to R. cerealis, whereas TaRCR1 overexpression significantly increased the resistance in transgenic wheat. TaRCR1 regulated certain reactive oxygen species (ROS)-scavenging and production, and defence-related genes, and peroxidase activity. Furthermore, H2 O2 pretreatment for 12-h elevated expression levels of TaRCR1 and the above defence-related genes, whereas treatment with a peroxidase inhibitor for 12 h reduced the resistance of TaRCR1-overexpressing transgenic plants and expression levels of these defence-related genes. Taken together, TaRCR1 positively contributes to defence response to R. cerealis through maintaining ROS homoeostasis and regulating the expression of defence-related genes.
Assuntos
Resistência à Doença/genética , Doenças das Plantas/microbiologia , Proteínas de Plantas/metabolismo , Rhizoctonia/patogenicidade , Triticum/metabolismo , Triticum/microbiologia , Resistência à Doença/fisiologia , Regulação da Expressão Gênica de Plantas/genética , Regulação da Expressão Gênica de Plantas/fisiologia , Doenças das Plantas/genética , Proteínas de Plantas/genética , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais/genética , Transdução de Sinais/fisiologia , Triticum/genéticaRESUMO
Sharp eyespot disease (primarily caused by the pathogen Rhizoctonia cerealis) and freezing stress are important yield limitations for the production of wheat (Triticum aestivum). Here, we report new insights into the function and underlying mechanisms of an ethylene response factor (ERF) in wheat, Pathogen-Induced ERF1 (TaPIE1), in host responses to R. cerealis and freezing stresses. TaPIE1-overexpressing transgenic wheat exhibited significantly enhanced resistance to both R. cerealis and freezing stresses, whereas TaPIE1-underexpressing wheat plants were more susceptible to both stresses relative to control plants. Following both stress treatments, electrolyte leakage and hydrogen peroxide content were significantly reduced, and both proline and soluble sugar contents were elevated in TaPIE1-overexpressing wheat, whereas these physiological traits in TaPIE1-underexpressing wheat exhibited the opposite trend. Microarray and quantitative reverse transcription-polymerase chain reaction analyses of TaPIE1-overexpressing and -underexpressing wheat plants indicated that TaPIE1 activated a subset of defense- and stress-related genes. Assays of DNA binding by electrophoretic mobility shift and transient expression in tobacco (Nicotiana tabacum) showed that the GCC boxes in the promoters of TaPIE1-activated genes were essential for transactivation by TaPIE1. The transactivation activity of TaPIE1 and the expression of TaPIE1-activated defense- and stress-related genes were significantly elevated following R. cerealis, freezing, and exogenous ethylene treatments. TaPIE1-mediated responses to R. cerealis and freezing were positively modulated by ethylene biosynthesis. These data suggest that TaPIE1 positively regulates the defense responses to R. cerealis and freezing stresses by activating defense- and stress-related genes downstream of the ethylene signaling pathway and by modulating related physiological traits in wheat.
Assuntos
Etilenos/metabolismo , Congelamento , Interações Hospedeiro-Patógeno , Proteínas de Plantas/metabolismo , Rhizoctonia/fisiologia , Estresse Fisiológico , Triticum/microbiologia , Triticum/fisiologia , Adaptação Fisiológica/genética , Sequência de Bases , Regulação para Baixo/genética , Etilenos/biossíntese , Regulação da Expressão Gênica de Plantas , Genes de Plantas , Interações Hospedeiro-Patógeno/genética , Modelos Biológicos , Dados de Sequência Molecular , Plantas Geneticamente Modificadas , Ligação Proteica , Característica Quantitativa Herdável , Sequências Reguladoras de Ácido Nucleico/genética , Transdução de Sinais/genética , Estresse Fisiológico/genética , Fatores de Transcrição/metabolismo , Triticum/genética , Triticum/imunologia , Regulação para Cima/genéticaRESUMO
Considerable progress has been made in understanding the roles of AGC kinases in mammalian systems. However, very little is known about the roles of AGC kinases in wheat (Triticum aestivum). The necrotrophic fungus Rhizoctonia cerealis is the major pathogen of the destructive disease sharp eyespot of wheat. In this study, the wheat AGC kinase gene TaAGC1, responding to R. cerealis infection, was isolated, and its properties and role in wheat defence were characterized. R. cerealis-resistant wheat lines expressed TaAGC1 at higher levels than susceptible wheat lines. Sequence and phylogenetic analyses showed that the TaAGC1 protein is a serine/threonine kinase belonging to the NDR (nuclear Dbf2-related) subgroup of AGC kinases. Kinase activity assays proved that TaAGC1 is a functional kinase and the Asp-239 residue located in the conserved serine/threonine kinase domain of TaAGC1 is required for the kinase activity. Subcellular localization assays indicated that TaAGC1 localized in the cytoplasm and nucleus. Virus-induced TaAGC1 silencing revealed that the down-regulation of TaAGC1 transcripts significantly impaired wheat resistance to R. cerealis. The molecular characterization and responses of TaAGC1 overexpressing transgenic wheat plants indicated that TaAGC1 overexpression significantly enhanced resistance to sharp eyespot and reduced the accumulation of reactive oxygen species (ROS) in wheat plants challenged with R. cerealis. Furthermore, ROS-scavenging and certain defence-associated genes were up-regulated in resistant plants overexpressing TaAGC1 but down-regulated in susceptible knock-down plants. These results suggested that the kinase TaAGC1 positively contributes to wheat immunity to R. cerealis through regulating expression of ROS-related and defence-associated genes.
Assuntos
Regulação da Expressão Gênica de Plantas , Doenças das Plantas/imunologia , Imunidade Vegetal , Rhizoctonia/fisiologia , Triticum/genética , Dados de Sequência Molecular , Filogenia , Doenças das Plantas/genética , Doenças das Plantas/microbiologia , Proteínas de Plantas , Análise de Sequência de DNA , Triticum/imunologia , Triticum/microbiologiaRESUMO
Background: Extraskeletal mesenchymal chondrosarcoma (ESMC), an uncommon and highly aggressive form of chondrosarcoma, is characterized by its mesenchymal origin and absence of skeletal involvement. Only a few cases of primary ESMC with metastasis to the pancreas have been reported so far. In this study, we present a case of ESMC in the left thigh with a solitary pancreatic metastasis in a 45-year-old woman. Additionally, we provide a thorough overview of ESMC, encompassing its entire clinical progression and radiographic observations. Furthermore, we reviewed all thirteen cases of pancreatic metastasis, including this present case, analyzing patient attributes, clinical management, and prognosis. Case presentation: A 45-year-old woman has had a painless mass in her left thigh for one year. X-ray, computed tomography (CT), and magnetic resonance imaging of the left thigh were performed. Positron emission tomography-CT imaging showed a high accumulation in the left thigh tumor and the pancreatic neck lesion. A diagnosis of extraskeletal chondrosarcoma with pancreatic metastasis was determined based on the radiological examinations. A final diagnosis of ESMC was confirmed by histopathological and immunohistochemical examinations after surgical resection. The patient presented metastasis in the lung, right groin, and tail of the pancreas successively, and mostly received complete surgical excision during a 39-month follow-up with postoperative chemotherapy. Conclusion: We present a highly uncommon case of ESMC spreading to the pancreas and highlight the importance of recognizing the distinctive imaging features of ESMC for diagnosis and prognosis assessment.
RESUMO
Paragangliomas (PGLs) are rare neuroendocrine tumors which overproduce catecholamines (CAs). They are extra-adrenal, catecholamine-secreting tumors occurring outside the adrenal glands. Gastric PGLs originating from extra-adrenal paraganglia are exceptionally rare, and their presentation in geriatric patients further adds to the complexity of diagnosis and management. A 72-year-old male patient presented with enduring left upper abdominal pain and anemia persisting for over a year, and hypertension for six months. Physical examination revealed epigastric discomfort and pallor. Computed tomography scans revealed enlarged lymph nodes in the lesser curvature of the stomach and thickening of the gastric antrum wall with concavity. The patient underwent three cycles of neoadjuvant therapy before radical gastrectomy for gastric cancer. These imaging findings were confirmed during surgery and intraoperative blood pressure was in fluctuation. After the successful resection of the tumor, postoperative pathology confirmed paraganglioma. During postoperative examination, it was observed that the patient's CAs and their metabolites had returned to within the normal range. Combined with the existing ten literatures, we retrospective report the clinical and pathological characteristics and treatment strategies of the rare gastric paraganglioma.