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OBJECTIVES: To explore the potential of artificial intelligence (AI) to assist prescription determination for orthokeratology (OK) lenses. METHODS: Artificial intelligence algorithm development followed by a real-world trial. A total of 11,502 OK lenses fitting records collected from seven clinical environments covering major brands. Records were randomly divided in a three-way data split. Cross-validation was used to identify the most accurate algorithm, followed by an evaluation using an independent test data set. An online AI-assisted system was implemented and assessed in a real-world trial involving four junior and three senior clinicians. RESULTS: The primary outcome measure was the algorithm's accuracy (ACC). The ACC of the best performance of algorithms to predict the targeted reduction amplitude, lens diameter, and alignment curve of the prescription was 0.80, 0.82, and 0.83, respectively. With the assistance of the AI system, the number of trials required to determine the final prescription significantly decreased for six of the seven participating clinicians (all P <0.01). This reduction was more significant among junior clinicians compared with consultants (0.76±0.60 vs. 0.32±0.60, P <0.001). Junior clinicians achieved clinical outcomes comparable to their seniors, as 93.96% (140/149) and 94.44% (119/126), respectively, of the eyes fitted achieved unaided visual acuity no worse than 0.8 ( P =0.864). CONCLUSIONS: AI can improve prescription efficiency and reduce discrepancies in clinical outcomes among clinicians with differing levels of experience. Embedment of AI in practice should ultimately help lessen the medical burden and improve service quality for myopia boom emerging worldwide.
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Algoritmos , Inteligencia Artificial , Miopía , Procedimientos de Ortoqueratología , Prescripciones , Humanos , Procedimientos de Ortoqueratología/métodos , Miopía/terapia , Miopía/fisiopatología , Femenino , Masculino , Lentes de Contacto , Niño , Ajuste de Prótesis/métodos , Adolescente , Agudeza Visual/fisiologíaRESUMEN
Gas temperature and density of Ar metastable state in DBD Ar (Ar/N(2)) plasma were measured using the tunable diode-laser absorption spectroscopy technology at low pressure. The variation trend of the densities of Ar metastable state 1s(5), 1s(3) and gas temperature with voltage, pressure, gas flow, electrode distance and N(2) concentration was studied. The density of Ar metastable was obtained by calculating the absorption peak area of absorption line based on the Lambert-Beer law, while gas temperature was determined with Doppler width of the absorption line in Voigt fitting. We deduced that the main source of the Ar metastable was the electron-impact excitation from the ground state, and the main loss process was the electron quenching. In addition, the actual discharge power, the electron state and the collision between particles were responsible for the variation of gas temperature. It was found that, when the voltage and gas flow increasing, both temperature and densities of 1s(5), 1s(3) shown the similar trends, which increasing rapidly at first and then slowly. In addition, the variation with gas flow was smaller than that with gas flow. With pressure increasing, temperature and densities of 1s(5), 1s(3) increased till to a max value and then decreased. Meanwhile, the experimental data indicated that the pressure had a greater effect on spectral line width. To increase the electrode distance properly, the density of 1s(5), 1s(3) decreased while the gas temperature increased. N(2) added to Ar presented a great negative effect on the density of Ar metastable state. Even 0.5% N(2) added to Ar, the densities of 1s(5) and 1s(3) decreased rapidly about to 50%, but then more N(2) added, there was no obvious decrease about density.
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BACKGROUND: Bacterial blight, caused by Xanthomonas oryzae pv. oryzae (Xoo), is a devastating rice disease worldwide. Xa39 is a resistance (R) gene with a broad-spectrum hypersensitive response (BSHR) to Xoo. Nevertheless, the molecular mechanisms of resistance mediated by Xa39 remain unclear. In this study, the transcriptome profiling of a rice line carrying Xa39 and its parents at the early stage of Xoo infection were investigated. RESULTS: A rice introgression line H471 carrying Xa39 exhibited a typical local hypersensitive response phenotype, accompanied by programmed cell death after inoculation with the Xoo Philippines' race 9b. Transcriptome profiling of H471 and its parents at 1 and 2 days post-inoculation was performed using RNA sequencing. In total, 306 differentially expressed genes (DEGs) were identified in H471 compared with its recurrent parent Huang-Hua-Zhan after inoculation with Xoo. Among them, 121 (39.5%) genes, with functional enrichments that were related to defense response, protein amino acid phosphorylation, and apoptosis, were found to be constitutively expressed. The other 185 (60.5%) genes, with GO terms that belonged to defense response, were significantly responsive to Xoo infection in H471. Ten up-regulated and 12 down-regulated genes encoding intracellular immune receptors were identified in H471 compared with Huang-Hua-Zhan. LOC_Os11g37759, which was located in the fine-mapping region harboring Xa39, is a Xa39 candidate gene. The putative BSHR-related co-regulatory networks were constructed using 33 DEGs from four functional groups, including gibberellic acid receptors and brassinosteroid regulators, which were differentially co-expressed with LOC_Os11g37759 in infected H471. Our results indicated that there might be cross-talk between the Xa39-mediated signal transduction cascades and the GA/BR signaling pathway, and that the defense mechanism was related to diverse kinases, transcription factors, post-translational regulation, and R genes. CONCLUSIONS: The present study provides the comprehensive transcriptome profile of a rice introgression line carrying Xa39 and its parents, and identifies a set of DEGs involved in BSHR mediated by Xa39. These data provide novel insights into the regulatory networks of plant disease resistance mediated by R genes, and the identified DEGs will serve as candidates for Xa39 cloning and for further understanding the molecular mechanism of BSHR.
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Perfilación de la Expresión Génica , Oryza/microbiología , Transcriptoma/genética , Xanthomonas/genética , Resistencia a la Enfermedad/genética , Regulación de la Expresión Génica de las Plantas , Redes Reguladoras de Genes , Análisis de Secuencia por Matrices de Oligonucleótidos , Oryza/genética , Enfermedades de las Plantas/microbiología , Proteínas de Plantas/biosíntesis , Proteínas de Plantas/genética , Transducción de Señal , Xanthomonas/patogenicidadRESUMEN
PURPOSE: RigidCare is an electrolysis-based device that recently obtained approval from the US's FDA to sterilise microorganisms and remove proteins for orthokeratology (O-K) lenses. The study was conducted to investigate the device's performance in varied clinical circumstances. METHODS: Trial lenses and private lenses were employed by O-K lens wearers from five hospitals for an evaluation of disinfection and sterilisation and an assessment of protein removal, respectively. Menicon multipurpose solution and protein remover were selected for use with the control group. Following the instructions, pre-cleaning lens samples, post-cleaning lens samples and residual solution samples of trial lenses of the experimental and control groups were collected for microorganism examinations by an experienced third-party testing organisation. The levels of protein deposition for these two approaches were rated by senior O-K experts. Categorical variables were analysed using statistical tests, such as the chi-squared test and Fisher's exact test. RESULTS: The microbial positive rate detected from the pre-cleaning and post-cleaning lens samples and the residual solution of the trial lenses for the experimental and control group was 4/76 vs 1/74 (P = 0.37), 1/76 vs 0/74 (P = 1.00) and 0/76 vs 8/74 (P = 0.006), respectively. Following protein removal, the experimental group exhibited a significantly higher overall proportion of lenses rated as 'clean' or with a 'mild deposit' (96.4 %, 79/82) compared to the control group (85.7 %, 66/77), with a significant difference (P < 0.05). CONCLUSION: This multi-center study demonstrated that RigidCare exhibited superior efficacy in disinfection, sterilisation and protein removal as compared to Menicon multipurpose solution and protein remover.
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Lentes de Contacto Hidrofílicos , Cristalino , Humanos , Desinfección , Soluciones para Lentes de Contacto/farmacologíaRESUMEN
BACKGROUND: Post-cholecystectomy diarrhea (PCD) frequently occurs in patients following gallbladder removal. PCD is part of the post-cholecystectomy (PC) syndrome, and is difficult to treat. After cholecystectomy, bile enters the duodenum directly, independent of the timing of meals. The interaction between the bile acids and the intestinal microbes is changed. Therefore, the occurrence of PCD may be related to the change in microbiota. However, little is known about the relationship between the gut microbiota and PCD. AIM: To better understand the role of the gut microbiota in PCD patients. METHODS: Fecal DNA was isolated. The diversity and profiles of the gut microbiota were analyzed by performing high-throughput 16S rRNA gene sequencing. The gut microbiota were characterized in a healthy control (HC) group and a PC group. Subsequently, the PC group was further divided into a PCD group and a post-cholecystectomy non-diarrhea group (PCND) according to the patients' clinical symptoms. The composition, diversity and richness of microbial communities were determined and compared. RESULTS: In the PC and HC groups, 720 operational taxonomic units (OTUs) were identified. The PC group had fewer OTUs than the HC group. ß-diversity was decreased in the PC group. This indicated decreased microbial diversity in the PC group. Fifteen taxa with differential abundance between the HC and PC groups were identified. In the PCD group compared to the PCND group, significant decreases in microbial diversity, Firmicutes/Bacteroidetes ratio, and richness of probiotic microbiota (Bifidobacterium and Lactococcus), and an increase in detrimental microbiota (Prevotella and Sutterella) were observed. Moreover, a negative correlation was found between Prevotella and Bifidobacterium. Using a Kyoto Encyclopedia of Genes and Genomes functional analysis, it was found that the abundances of gut microbiota involved in lipid metabolism pathways were markedly lower in the PCD group compared to the PCND group. CONCLUSION: This study demonstrated that gut dysbiosis may play a critical role in PCD, which provides new insights into therapeutic options for PCD patients.
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Microbioma Gastrointestinal , Colecistectomía , Diarrea/etiología , Disbiosis , Humanos , ARN Ribosómico 16S/genéticaRESUMEN
BACKGROUND: Non-host resistance in rice to its bacterial pathogen, Xanthomonas oryzae pv. oryzicola (Xoc), mediated by a maize NBS-LRR type R gene, Rxo1 shows a typical hypersensitive reaction (HR) phenotype, but the molecular mechanism(s) underlying this type of non-host resistance remain largely unknown. RESULTS: A microarray experiment was performed to reveal the molecular mechanisms underlying HR of rice to Xoc mediated by Rxo1 using a pair of transgenic and non-transgenic rice lines. Our results indicated that Rxo1 appeared to function in the very early step of the interaction between rice and Xoc, and could specifically activate large numbers of genes involved in signaling pathways leading to HR and some basal defensive pathways such as SA and ET pathways. In the former case, Rxo1 appeared to differ from the typical host R genes in that it could lead to HR without activating NDR1. In the latter cases, Rxo1 was able to induce a unique group of WRKY TF genes and a large set of genes encoding PPR and RRM proteins that share the same G-box in their promoter regions with possible functions in post-transcriptional regulation. CONCLUSIONS: In conclusion, Rxo1, like most host R genes, was able to trigger HR against Xoc in the heterologous rice plants by activating multiple defensive pathways related to HR, providing useful information on the evolution of plant resistance genes. Maize non-host resistance gene Rxo1 could trigger the pathogen-specific HR in heterologous rice, and ultimately leading to a localized programmed cell death which exhibits the characteristics consistent with those mediated by host resistance genes, but a number of genes encoding pentatricopeptide repeat and RNA recognition motif protein were found specifically up-regulated in the Rxo1 mediated disease resistance. These results add to our understanding the evolution of plant resistance genes.
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Oryza/microbiología , Proteínas de Plantas/genética , Xanthomonas , Zea mays/genética , Regulación de la Expresión Génica de las Plantas , Genoma de Planta , Inmunidad Innata , Análisis de Secuencia por Matrices de Oligonucleótidos , Oryza/genética , Oryza/inmunología , Oryza/metabolismo , Enfermedades de las Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Modificadas Genéticamente/genética , Plantas Modificadas Genéticamente/inmunología , Plantas Modificadas Genéticamente/metabolismo , Plantas Modificadas Genéticamente/microbiología , Regiones Promotoras Genéticas , ARN de Planta/genética , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Factores de Transcripción/genéticaRESUMEN
BACKGROUND: Sheath blight (ShB), caused by Rhizoctonia solani Kühn, is one of the most destructive rice diseases. Developing ShB-resistant rice cultivars represents the most economical and environmentally sound strategy for managing ShB. RESULTS: To characterize the genetic basis for ShB resistance in rice, we conducted association studies for traits related to ShB resistance, namely culm length (CL), lesion height (LH), and relative lesion height (RLH). Combined a single locus genome-wide scan and a multi-locus method using 2,977,750 single-nucleotide polymorphisms to analyse 563 rice accessions, we detected 134, 562, and 75 suggestive associations with CL, LH, and RLH, respectively. The adjacent signals associated with RLH were merged into 27 suggestively associated loci (SALs) based on the estimated linkage disequilibrium blocks. More than 44% of detected RLH-SALs harboured multiple QTLs/genes associated with ShB resistance, while the other RLH-SALs were putative novel ShB resistance loci. A total of 261 ShB resistance putative functional genes were screened from 23 RLH-SALs according to bioinformatics and haplotype analyses. Some of the annotated genes were previously reported to encode defence-related and pathogenesis-related proteins, suggesting that quantitative resistance to ShB in rice is mediated by SA- and JA-dependent signalling pathways. CONCLUSIONS: Our findings may improve the application of germplasm resources as well as knowledge-based ShB management and the breeding of ShB-resistant rice cultivars.
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In the present paper, the effects of the ethanol-water solution temperature (20, 40, and 60 degrees C) on the emission intensity of ICP source, plasma parameters (excitation temperature and electron density), physical properties (surface tension and viscosity) of sample solution, and nebulization (uptake rate, effective uptake rate and nebulization efficiency) were studied by using optical-to-electrical detection method. The experimental results showed that the velocity of the sample entering the plasma increased, so that the line intensity of the elements Zn, Fe, Mg, Si, and Sr in water increased obviously with increasing the content of ethanol and the rise of the corresponding solution temperature. And the excitation capacity in the plasma was strengthened with the rise of the ethanol-water solution temperature. The maximal spectrum intensity of the elements Zn, Fe, Mg, Si, and Sr at 60 degrees C was higher by 55.8%, 45.4%, 48.9%, 17.7%, and 21.6% than that at 20 degrees C, respectively. It's valuable for the detection of the trace element.
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In the present paper, the physics property and nebulization character of the sample solution as well as elemental spectrum intensity were investigated with the prolonging of magnetization time after the water solution with the ethanol was magnetized under magnetic field of 0.24T. The magnetization mechanism was discussed. The experiment result shows that the efficient age-rate of the analyzed sample is increased. The peak values of the spectrum intensity appear when the ethanol is added into the sample. Under the magnetization time of 2 hours, the spectrum intensities of Zn, Pb, Cd, Fe, Si, Cu, Cr and Sr in the sample solution without the ethanol were increased by 22.9%, 38.8%, 25.6%, 48.3%, 52.4%, 6.0%, 22.3% and 22.7% than that with the non-magnetic water, respectively; The signal intensities of the elements in the sample solution with the ethanol of 6% were increased by 22.4%, 42.6%, 39.4%, 72.4%, 43.9%, 9.7%, 16.1% and 17.1% than that with the non-magnetic water, respectively. The detection limit of spectral analysis was reduced when the magnetized sample solution was analyzed.
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Bacterial blight, which is caused by Xanthomonas oryzae pv. oryzae (Xoo), is one of the most devastating rice diseases worldwide. The development and use of disease-resistant cultivars have been the most effective strategy to control bacterial blight. Identifying the genes mediating bacterial blight resistance is a prerequisite for breeding cultivars with broad-spectrum and durable resistance. We herein describe a genome-wide association study involving 172 diverse Oryza sativa ssp. indica accessions to identify loci influencing the resistance to representative strains of six Xoo races. Twelve resistance loci containing 121 significantly associated signals were identified using 317,894 single nucleotide polymorphisms, which explained 13.3-59.9% of the variability in lesion length caused by Xoo races P1, P6, and P9a. Two hotspot regions (L11 and L12) were located within or nearby two cloned R genes (xa25 and Xa26) and one fine-mapped R gene (Xa4). Our results confirmed the relatively high resolution of genome-wide association studies. Moreover, we detected novel significant associations on chromosomes 2, 3, and 6-10. Haplotype analyses of xa25, the Xa26 paralog (MRKc; LOC_Os11g47290), and a Xa4 candidate gene (LOC_11g46870) revealed differences in bacterial blight resistance among indica subgroups. These differences were responsible for the observed variations in lesion lengths resulting from infections by Xoo races P1 and P9a. Our findings may be relevant for future studies involving bacterial blight resistance gene cloning, and provide insights into the genetic basis for bacterial blight resistance in indica rice, which may be useful for knowledge-based crop improvement.
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Resistencia a la Enfermedad/genética , Genoma de Planta , Estudio de Asociación del Genoma Completo/métodos , Oryza/genética , Enfermedades de las Plantas/genética , Mapeo Cromosómico , Cromosomas de las Plantas/genética , Genes de Plantas/genética , Sitios Genéticos/genética , Genotipo , Haplotipos , Interacciones Huésped-Patógeno , Oryza/clasificación , Oryza/microbiología , Filogenia , Enfermedades de las Plantas/microbiología , Polimorfismo de Nucleótido Simple , Semillas/genética , Semillas/microbiología , Especificidad de la Especie , Xanthomonas/fisiologíaRESUMEN
Ferric ion modified attapulgite (Fe/ATP) was prepared by impregnation and its structure and morphology were characterized. The toxicity characteristic leaching procedure (TCLP) was used to evaluate the effect of Cadmium( Cd) stabilization in soil with the addition of attapulgite (ATP) and Fe/ATP. The stabilization mechanism of Cd was further elucidated by comparing the morphologies and structure of ATP and Fe/ATP before and after Cd adsorption. Fe/ATP exhibited much better adsorption capacity than ATP, suggesting different adsorption mechanisms occurred between ATP and Fe/ATP. The leaching concentrations of Cd in soil decreased by 45% and 91% respectively, with the addition of wt. 20% ATP and Fe/ATP. The former was attributed to the interaction between Cd2 and --OH groups by chemical binding to form inner-sphere complexes in ATP and the attachment between Cd2+ and the defect sites in ATP framework. Whereas Cd stabilization with Fe/ATP was resulted from the fact that the active centers (--OH bonds or O- sites) on ATP could react with Fe3+ giving Fe--O--Cd-- bridges, which helped stabilize Cd in surface soil. What'more, the ferric oxides and metal hydroxides on the surface of ATP could interact with Cd, probably by the formation of cadmium ferrite. In conclusion, Fe/ATP, which can be easily prepared, holds promise as a potential low-cost and environmental friendly stabilizing agent for remediation of soil contaminated with heavy metals.
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Cadmio/análisis , Compuestos de Magnesio/química , Compuestos de Silicona/química , Contaminantes del Suelo/análisis , Adsorción , Compuestos Férricos/química , Hierro/química , SueloRESUMEN
A clinical analysis of hyperthyroidism heart diseases was conducted in 31 elderly patients, of whom 15 (48.4%) had been misdiagnosed before accurate diagnoses were reached 4 months to 3 years later. Among the 15 misdiagnosed cases, 9 were misdiagnosed as coronary heart disease, 3 as pulmonary heart disease, 2 as hypertension heart disease and 1 as dilated cardiomyopathy. This result suggests that physicians need to be more aware of elderly hyperthyroidism, and thorough history inquiry, systemic examination and timely thyroid function test can reduce the misdiagnosis of hyperthyroid heart disease in elderly patients.
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Cardiopatías/patología , Hipertiroidismo/complicaciones , Anciano , Diagnóstico Diferencial , Femenino , Cardiopatías/complicaciones , Humanos , Masculino , Persona de Mediana EdadRESUMEN
AIM: To investigate the incidence of gastroesophageal reflux disease (GERD) and its related risk factors in Uygur and Han Chinese adult in Urumqi, China. METHODS: A population-based cross-sectional survey was undertaken in a total of 972 Uygur (684 male and 288 female) aged from 24 to 61 and 1023 Han Chinese (752 male and 271 female) aged from 23 to 63 years. All participants were recruited from the residents who visited hospital for health examination from November 2011 to May 2012. Each participant signed an informed consent and completed a GERD questionnaire (Gerd Q) and a lifestyle-food frequency questionnaire survey. Participants whose Gerd Q score was ≥ 8 and met one of the following requirements would be enrolled into this research: (1) being diagnosed with erosive esophagitis (EE) or Barrett's esophagus (BE) by endoscopy; (2) negative manifestation under endoscopy (non-erosive reflux disease, NERD) with abnormal acid reflux revealed by 24-h esophageal pH monitoring; and (3) suffering from typical heartburn and regurgitation with positive result of proton pump inhibitor test. RESULTS: According to Gerd Q scoring criteria, 340 cases of Uygur and 286 cases of Han Chinese were defined as GERD. GERD incidence in Uygur was significantly higher than in Han Chinese (35% vs 28%, χ(2) = 11.09, P < 0.005), Gerd Q score in Uygur was higher than in Han Chinese (7.85 ± 3.1 vs 7.15 ± 2.9, P < 0.005), and Gerd Q total score in Uygur male was higher than in female (8.15 ± 2.8 vs 6.85 ± 2.5, P < 0.005). According to normalized methods, 304 (31%) cases of Uygur were diagnosed with GERD, including 89 cases of EE, 185 cases of NERD and 30 cases of BE; 256 (25%) cases of Han Chinese were diagnosed with GERD, including 90 cases of EE, 140 cases of NERD and 26 cases of BE. GERD incidence in Uygur was significantly higher than in Han Chinese (31% vs 25%, χ(2) = 9.34, P < 0.005) while the incidences were higher in males of both groups than in females (26% vs 5% in Uygur, χ(2) = 35.95, P < 0.005, and 19.8% vs 5.2% in Han, χ(2) = 5.48, P < 0.025). GERD incidence in Uygur male was higher than in Han Chinese male (26% vs 19.8%, χ(2) = 16.51, P < 0.005), and incidence of NERD in Uygur was higher than in Han Chinese (χ(2) = 10.06, P < 0.005). Occupation (r = 0.623), gender (r = 0.839), smoking (r = 0.322), strong tea (r = 0.658), alcohol drinking (r = 0.696), meat-based diet (mainly meat) (r = 0.676) and body mass index (BMI) (r = 0.567) were linearly correlated with GERD in Uygur (r = 0.833, P = 0.000); while gender (r = 0.957), age (r = 0.016), occupation (r = 0.482), strong tea (r = 1.124), alcohol drinking (r = 0.558), meat diet (r = 0.591) and BMI (r = 0.246) were linearly correlated with GERD in Han Chinese (r = 0.786, P = 0.01). There was no significant difference between Gerd Q scoring and three normalized methods for the diagnosis of GERD. CONCLUSION: GERD is highly prevalent in adult in Urumqi, especially in Uygur. Male, civil servant, smoking, strong tea, alcohol drinking, meat diet and BMI are risk factors correlated to GERD.
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Reflujo Gastroesofágico/diagnóstico , Reflujo Gastroesofágico/etnología , Reflujo Gastroesofágico/epidemiología , Adulto , Anciano , Consumo de Bebidas Alcohólicas , Índice de Masa Corporal , China/epidemiología , Estudios Transversales , Dieta , Esófago/patología , Etnicidad , Femenino , Humanos , Concentración de Iones de Hidrógeno , Incidencia , Masculino , Persona de Mediana Edad , Factores de Riesgo , Fumar , Encuestas y Cuestionarios , TéRESUMEN
Rice bacterial leaf streak,caused by Xanthomonas oryzae pv. oryzicola is a destructive bacterial disease in China. Single-gene resistance to X. oryzae pv. oryzicola has not been found in rice germplasm. A cloned non-host gene from maize with resistance to bacterial leaf streak, Rxo1, was transferred into four Chinese rice varieties through an Agrobacterium-mediated system, including Zhonghua11, 9804, C418 and Minghui86. PCR and Southern analysis of the transgenic plants revealed the integration of the Rxo1 gene into the rice genomes. The integrated Rxo1 was stably inherited, and segregated in a 3:1 (Resistance:Susceptible) ratio in the selfed T1 generations derived from some T0 plants, indicating that Rxo1 inherited as a dominate gene in rice. Transgenic T0 plants and PCR-positive T1 plants were resistant to X. oryzae pv. oryzicola on the basis of artificial inoculation.
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Proteínas Bacterianas/genética , Oryza/genética , Plantas Modificadas Genéticamente/genética , Xanthomonas , Zea mays/genética , Proteínas Bacterianas/metabolismo , Genes de Plantas/genética , Enfermedades de las Plantas/genética , Enfermedades de las Plantas/microbiología , Rhizobium/genética , Transformación Genética , Xanthomonas/genética , Zea mays/microbiologíaRESUMEN
The recessive gene xa5 for resistance to bacterial blight resistance of rice is located on chromosome 5, and evidence based on genetic recombination has been shown to encode a small subunit of the basal transcription factor IIA (Iyer and McCouch in MPMI 17(12):1348-1354, 2004). However, xa5 has not been demonstrated by a complementation test. In this study, we introduced the dominant allele Xa5 into a homozygous xa5-line, which was developed from a cross between IRBB5 (an indica variety with xa5) and Nipponbare (a japonica variety with Xa5). Transformation of Xa5 and subsequent segregation analysis confirmed that xa5 is a V39E substitution variant of the gene for TFIIAgamma on chromosome 5 (TFIIAgamma5 or Xa5). The rice has an addition gene for TFIIAgamma exists on chromosome 1 (TFIIAgamma1). Analysis of the expression patterns of Xa5 (TFIIAgamma5)/xa5 and TFIIAgamma1 revealed that both the genes are constitutively expressed in different rice organs. However, no expression of TFIIAgamma1 could be detected in the panicle by reverse transcriptase-polymerase chain reaction. To compare the structural difference between the Xa5/xa5 and TFIIAgamma1 proteins, 3-D structures were predicted using computer-aided modeling techniques. The modeled structures of Xa5 (xa5) and TFIIAgamma1 fit well with the structure of TFIIA small subunit from human, suggesting that they may all act as a small subunit of TFIIA. The E39V substitution in the xa5 protein occurs in the alpha-helix domain, a supposed conservative substitutable site, which should not affect the basal transcription function of TFIIAgamma. The structural analysis indicates that xa5 and Xa5 potentially retain their basic transcription factor function, which, in turn, may mediate the novel pathway for bacterial blight resistance and susceptibility, respectively.
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Genes de Plantas , Oryza/fisiología , Enfermedades de las Plantas/genética , Proteínas de Plantas/química , Proteínas de Plantas/genética , Mapeo Cromosómico , Regulación de la Expresión Génica de las Plantas , Prueba de Complementación Genética , Predisposición Genética a la Enfermedad , Modelos Moleculares , Datos de Secuencia Molecular , Oryza/microbiología , Filogenia , Enfermedades de las Plantas/microbiología , Proteínas de Plantas/metabolismo , Plantas Modificadas Genéticamente , Conformación Proteica , Homología de Secuencia de Aminoácido , Homología Estructural de Proteína , Factor de Transcripción TFIIA/química , Factor de Transcripción TFIIA/genética , Xanthomonas/patogenicidadRESUMEN
The mutant population of Xanthomonas oryzae pv oryzae strain differential to rice bacterial blight resistance gene Xa23 has been constructed mediated by transposon in vivo . The results of PCR amplification with specific primers and analysis of flanking sequence of mutants indicated that the foreign DNA has been integrated into X. oryzae pv oryzae genome. Four mutants with changed avirulent activity to Xa23 gene have been identified by artificial inoculation. It is possible to clone genes that are required for AvrXa23 avirulence activity using this new strategy.
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Oryza/genética , Oryza/microbiología , Enfermedades de las Plantas/microbiología , Xanthomonas/genética , Proteínas Bacterianas/genética , Secuencia de Bases , Elementos Transponibles de ADN , Regulación de la Expresión Génica de las Plantas , Genes de Plantas , Datos de Secuencia Molecular , Mutación , Plantas Modificadas Genéticamente/genética , Plantas Modificadas Genéticamente/microbiología , Virulencia , Xanthomonas/patogenicidad , Xanthomonas/fisiologíaRESUMEN
Northern corn leaf blight, caused by the fungus Exserohirum turcicum Pass. (Leonard and Suggs), is one of the major diseases in most corn-growing areas of the world. Research on gene tagging of E. turcicum has been limited due to the lack of an efficient transformation system. Since E. turcicum produces and accumulates melamin in cell walls during vegetative growth, it is difficult to efficiently isolate its protoplast. To isolate the protoplast of this pathogen with a high frequency, the effects of cell wall degradation enzymes, including beta-1,3-glucanase (Fungase, Funcelase, Novozyme and Glucanex) and beta-glucuronidase (Driselase, Uskizyme and Kitalase), enzyme concentrations, combinations, strains and medium on the isolation frequency were tested. The isolation frequencies were high enough for transformation when the combinations of (Kitalase + Glucanex + Driselase), (Kitalase + Glucanex) or (Kitalase + Uskizyme) were used. Moreover, the isolation frequencies of protoplast were significantly affected by the cultural morphologies of strain and the growth stage of mycelia. Among the plasmids tested, only plasmid pAN71 is efficient for transformation of E. turcicum. This result will provide some useful information for gene tagging of E. turcicum and other species in Exserohirum.