Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 27
Filtrar
Más filtros

Bases de datos
País/Región como asunto
Tipo del documento
País de afiliación
Intervalo de año de publicación
1.
Plant Dis ; 107(11): 3623-3626, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-37189043

RESUMEN

Xanthomonas oryzae pv. oryzae (Xoo), the causal agent of bacterial leaf blight (BLB), is one of the most destructive bacterial pathogens in rice production worldwide. Although several complete genome sequences of Xoo strains have been released in public databases, they are mainly isolated from low-altitude indica rice cultivating areas. Here, a hypervirulent strain, YNCX, isolated from the high-altitude japonica rice-growing region in Yunnan Plateau, was used to extract genomic DNA for PacBio sequencing and Illumina sequencing. After assembly, a high-quality complete genome consisting of a circular chromosome and six plasmids was generated. The genome sequence of YNCX provides a valuable resource for high-altitude races and enables the identification of new virulence TALE effectors, contributing to a better understanding of rice-Xoo interactions.


Asunto(s)
Oryza , Xanthomonas , Oryza/microbiología , China , Virulencia/genética
2.
Zhonghua Yi Xue Yi Chuan Xue Za Zhi ; 40(10): 1241-1245, 2023 Oct 10.
Artículo en Zh | MEDLINE | ID: mdl-37730224

RESUMEN

OBJECTIVE: To explore the laboratory phenotype and molecular pathogenesis in a Chinese pedigree affected with Hereditary coagulation factor Ⅻ (FⅫ) deficiency. METHODS: A male proband admitted to Ningbo No.2 Hospital on July 17, 2021 due to chronic gastritis and members of his pedigree (7 individuals from three generations) were selected as the study subjects. Prothrombin time (PT), activated partial thromboplastin time (APTT), FⅧ activity (FⅧ: C), FⅨ activity (FⅨ: C), FⅪ activity (FⅪ: C), FⅫ activity (FⅫ: C), and FⅫ antigen (FⅫ: Ag) were determined. All of the exons, exon-intronic boundaries, as well as the 5'- and 3'-untranslated regions of the F12 gene were subjected to Sanger sequencing. Candidate variants were verified by cloning sequencing. The effect of candidate variants on the protein function was analyzed by bioinformatics software. RESULTS: The proband, a 47-year-old male, had significantly prolonged APTT (180.0 s) and decreased FⅫ:C and FⅫ:Ag levels (< 1%). His father, mother, brother and two sons also showed certain degrees of reduction. Genetic testing revealed that the proband has harbored compound heterozygous variants of the F12 gene, namely c.1092_1093insC (p.Lys365Glnfs*69) in exon 10 and c.1792_1796delGTCTA (p.Val579Hisfs*32) in exon 14. His mother and elder son were heterozygous for the c.1092_1093ins variant, whilst his father, brother, and younger son were heterozygous for the c.1792_1796delGTCTA variant. Analysis of the promoter region of exon 1 also showed that the proband and both sons had harbored a 46T/T polymorphism, whilst other family members were 46C/T. Bioinformatic analysis suggested that the p.Val579 is a highly conserved site. Protein model analysis showed that, with the p.Val579Hisfs*32 variant, a benzene ring was added and the hydrogen bond of surrounding amino acids was changed. Based on the guidelines from the American College of Medical Genetics and Genomics, the c.1792_1796delGTCTA was classified as a pathogenic variant (PVS1+PM2_Supporting+PM4). CONCLUSION: The c.1092_1093insC (p.Lys365Glnfs*69) and c.1792_1796delGTCTA (p.Val579Hisfs*32) compound heterozygous variants of the F12 gene probably underlay the decreased FXII levels in this pedigree. Above finding has also enriched the mutational spectrum for FⅫ deficiency.


Asunto(s)
Pueblos del Este de Asia , Deficiencia del Factor XII , Masculino , Humanos , Anciano , Persona de Mediana Edad , Linaje , Exones , Intrones , Familia , Deficiencia del Factor XII/genética , Regiones no Traducidas 3' , Factor XII/genética
3.
Analyst ; 147(22): 5223-5230, 2022 Nov 07.
Artículo en Inglés | MEDLINE | ID: mdl-36260081

RESUMEN

Uracil-DNA glycosylase (UDG) is a crucial repair enzyme, which is considered a reliable biomarker due to its abnormal expression associated with serious diseases. Herein, DNAzyme-powered cascade walkers were proposed for sensitive detection of UDG. The cascade walkers consisted of a fixed walker and a subsequently activated free walker. The fixed walker was constructed on 13 nm AuNPs by loading a fixed walking strand (WS1) and a track strand 1 (TS1). The WS1 contained a DNAzyme sequence, which was pre-locked by a locking strand (LS) with an uracil base. The TS1 inserted an RNA cleavage site and sealed the same DNAzyme. The free walker tracks were conjugated on 25 nm AuNPs by modifying a FAM-labeled track strand 2 (TS2) with an RNA cleavage site. When UDG specifically recognized the LS, the WS1 was released with the assistance of Endo·IV. Then the WS1 continuously cleaved TS1s to drive the fixed walker, thus releasing many sequences containing DNAzyme. The released sequences acted as free walking strands (WS2s) to repeatedly cleave TS2s to power the free walker, which led to fluorescence accumulation. The cascade walkers successfully detected UDG with a limit of 8.5 × 10-5 U mL-1. The cascade walkers offer a new method for sensitively analyzing glycosylase.


Asunto(s)
Técnicas Biosensibles , ADN Catalítico , Nanopartículas del Metal , Uracil-ADN Glicosidasa/metabolismo , ADN Catalítico/metabolismo , Oro , ADN/genética , Uracilo , Técnicas Biosensibles/métodos
4.
J Environ Sci Health B ; 57(11): 883-889, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36217592

RESUMEN

The heterologous strategy could improve the sensitivity of competitive enzyme-linked immunosorbent assay (ELISA) for detection of chemical contaminants in food samples. In this study, the heterologous coating antigen ELISA was developed to evaluate its sensitivity for mebendazole (MBZ). Results showed that the heterologous ELISA had a linear range of (IC20-IC80) 0.34-10.54 ng/mL, an IC50 value of 1.83 ng/mL, and a limit of detection (LOD) of 0.13 ng/mL, in which the sensitivity of ELISA improved 1.7- and 2-fold (IC50 value dropping from 7.41 and 3.65 ng/mL to 4.27 and 1.83 ng/mL) than that of rabbit IgG- and chicken IgY-based homologous ELISA for MBZ, respectively. The heterologous coating antigen ELISA showed negligible cross reactivity (<0.2%) with its structural analogues, including hydroxy-MBZ, albendazole, oxfendazole, fenbendazole, and flubendazole, except the value of 72.6% for amino-MBZ. The average recoveries of MBZ spiked in pork and chicken muscle samples by the assay ranged from 83.7% to 109.8% and agreed well with those of high-performance liquid chromatography. The results suggested that using heterologous coating antigen could distinctly improve the sensitivity of ELISA for routine screening of MBZ residues in food samples.


Asunto(s)
Antígenos Heterófilos , Mebendazol , Animales , Conejos , Antígenos Heterófilos/análisis , Ensayo de Inmunoadsorción Enzimática/métodos , Cromatografía Líquida de Alta Presión , Límite de Detección
5.
J Clin Lab Anal ; 35(8): e23911, 2021 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-34260764

RESUMEN

BACKGROUND: Dyslipidemia has been observed in patients with coronavirus disease 2019 (COVID-19). This study aimed to investigate blood lipid profiles in patients with COVID-19 and to explore their predictive values for COVID-19 severity. METHODS: A total of 142 consecutive patients with COVID-19 were included in this single-center retrospective study. Blood lipid profile characteristics were investigated in patients with COVID-19 in comparison with 77 age- and gender-matched healthy subjects, their predictive values for COVID-19 severity were analyzed by using multivariable logistic regression analysis, and their prediction efficiencies were evaluated by using receiver operator characteristic (ROC) curves. RESULTS: There were 125 and 17 cases in the non-severe and severe groups, respectively. Total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), and apolipoprotein A1 (ApoA1) gradually decreased across the groups in the following order: healthy controls, non-severe group, and severe group. ApoA1 was identified as an independent risk factor for COVID-19 severity (adjusted odds ratio [OR]: 0.865, 95% confidence interval [CI]: 0.800-0.935, p < 0.001), along with interleukin-6 (IL-6) (adjusted OR: 1.097, 95% CI: 1.034-1.165, p = 0.002). ApoA1 exhibited the highest area under the ROC curve (AUC) among all single markers (AUC: 0.896, 95% CI: 0.834-0.941); moreover, the risk model established using ApoA1 and IL-6 enhanced prediction efficiency (AUC: 0.977, 95% CI: 0.932-0.995). CONCLUSION: Blood lipid profiles in patients with COVID-19 are quite abnormal compared with those in healthy subjects, especially in severe cases. Serum ApoA1 may represent a good indicator for predicting the severity of COVID-19.


Asunto(s)
Apolipoproteína A-I/sangre , COVID-19/etiología , Adulto , Anciano , Área Bajo la Curva , Biomarcadores/sangre , COVID-19/sangre , COVID-19/epidemiología , Estudios de Casos y Controles , HDL-Colesterol/sangre , LDL-Colesterol/sangre , Comorbilidad , Femenino , Humanos , Lípidos/sangre , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Factores de Riesgo , Índice de Severidad de la Enfermedad
6.
BMC Ophthalmol ; 19(1): 228, 2019 Nov 14.
Artículo en Inglés | MEDLINE | ID: mdl-31726996

RESUMEN

BACKGROUND: To describe a peculiar case of concurrent non-arteritic anterior ischemic optic neuropathy (NAION) and cilioretinal arteries occlusion (CLRAO) without other causative agents which responded well to intravenous and intravitreal injection of corticosteroids. CASE PRESENTATION: A 41-year-old woman presented with painless vision loss in the right eye for 1 week. Fundus examinations showed marked disc swelling, flame-shaped hemorrhage over the superior nerve fiber area, and well-demarcated retinal ischemia superior to the fovea in the right eye. Under the impression of NAION with branch retinal artery occlusion, the patient was treated with intravenous and intravitreal injection of corticosteroids. Two months later, as the disc swelling and retinal ischemia resolved, we found that the occluded artery was the cilioretinal artery and not the ordinary branch retinal artery. CONCLUSIONS: CLRAO may be concomitant with the setting of NAION, the physicians should be aware that CLRAO may be misinterpreted as BRAO owing to profound disc edema during the early stages of the disease.


Asunto(s)
Corticoesteroides/uso terapéutico , Arteriopatías Oclusivas/tratamiento farmacológico , Arterias Ciliares/patología , Neuropatía Óptica Isquémica/tratamiento farmacológico , Triamcinolona/uso terapéutico , Adulto , Femenino , Humanos , Resultado del Tratamiento
7.
Small Methods ; : e2400572, 2024 May 14.
Artículo en Inglés | MEDLINE | ID: mdl-38741547

RESUMEN

This research addresses the pH-dependency limitation in electrocatalytic hydrogen evolution reactions (HER) by creating heterostructures through the chemical bonding between 2D-dichalcogenides and V4C3Tx (T = OH, O) planes. The one-step solvothermal synthesis employed in this study constructs a synergistically interacted 1T phase of, e.g., MoS2 and V4C3Tx MXene, demonstrating an omnidirectional improvement on catalytic stability, active site exposure, surface area enlargement, electrical conductivity, and hence enhancement of water dissociation activities. Despite the notable progress in creating hydrogen production catalysts with ground breaking performances, a significant gap remains in the availability of catalysts capable of functioning effectively under high current densities. The catalyst 1T MoS2@V4C3Tx shows remarkable activities under the current density of 1000 mA cm-2, which require overpotentials of 16, 24, and 37 mV in 0.5 m H2SO4, 1 m KOH, and 0.1 m PBS electrolytes, respectively at 10 mA cm-2, and exhibits excellent HER performance with small overpotentials of 103.16 and 138 mV to achieve current densities of 500 and 1000 mA cm-2, respectively, with outstanding stability for 1000 cylic voltammetric cycle HER test without degradation in acidic media. Enhanced HER performance has also been observed in other 2D-dichalcogenides/V4C3Tx heterostructures, providing prospects for phase-engineered dichalcogenides/fluorine-free V4C3Tx composites for pH-universal HER.

8.
Anal Methods ; 16(12): 1756-1762, 2024 Mar 22.
Artículo en Inglés | MEDLINE | ID: mdl-38440844

RESUMEN

Single-chain variable fragments (scFvs) are valuable in the development of immunoassays for pesticide detection. In this study, scFvs specific to thiamethoxam (Thi) were successfully isolated from a library generated by chicken immunization through heterologous coating selection. These scFvs were subsequently expressed with fusion with an Avi tag and alkaline phosphatase. After combination and optimization, a scFv-biotin based enzyme linked immunosorbent assay (ELISA) was developed for the detection of Thi, demonstrating an impressive half-maximum signal inhibition concentration (IC50) of 30 ng mL-1 and a limit of detection (LOD) of 1.8 ng mL-1. The immunoassay exhibited minimal cross-reactivity with other neonicotinoid insecticides, except for 7.5% for imidacloprid and 6.7% for imidaclothiz. The accuracy of the assay was confirmed by testing spiked samples of apple, pear, cabbage, and cucumber, which resulted in average recoveries ranging between 82% and 119%, closely aligning with the results obtained through high-performance liquid chromatography. Therefore, the chicken scFv-biotin based assay showed promise as a high-throughput screening tool for Thi in agricultural samples.


Asunto(s)
Insecticidas , Anticuerpos de Cadena Única , Animales , Tiametoxam , Anticuerpos de Cadena Única/genética , Anticuerpos de Cadena Única/química , Pollos , Biotina , Insecticidas/análisis
9.
Anal Methods ; 16(10): 1546-1553, 2024 Mar 07.
Artículo en Inglés | MEDLINE | ID: mdl-38404205

RESUMEN

The compound 3-phenoxybenzoic acid (3-PBA) is frequently utilized as a biomarker to detect exposure to various pyrethroids. In this study, a bivalent nanobody (Nb2) specifically targeting 3-PBA was biotinylated and immobilized onto streptavidin (SA)-modified bacterial magnetic nanoparticles (BMPs), resulting in the formation of BMP-SA-Biotin-Nb2 complexes. These complexes demonstrated remarkable stability when exposed to strongly acidic solutions (4 M HCl), methanol (80%), and high ionic strength (1.37 M NaCl). An immunoassay was subsequently developed utilizing BMP-SA-Biotin-Nb2 as the capture agent and 3-PBA-horseradish peroxidase as the detection probe. The immunoassay exhibited an IC50 value (half-maximum signal inhibition concentration) of 1.11 ng mL-1 for 3-PBA. To evaluate the accuracy of the assay, spiked sheep and cow urine samples (ranging from 3.0 to 240 ng mL-1) were analyzed. The quantitative recoveries ranged from 82.5% to 113.1%, which agreed well with the findings obtained using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Overall, the BMP-SA-Biotin-Nb2-based immunoassay holds great promise for rapid monitoring of 3-PBA following acid dissociation.


Asunto(s)
Benzoatos , Biotina , Magnetosomas , Femenino , Bovinos , Animales , Ovinos , Estreptavidina/química , Biotina/química , Ensayo de Inmunoadsorción Enzimática/métodos , Cromatografía Liquida , Espectrometría de Masas en Tándem
10.
Yi Chuan ; 34(11): 1466-74, 2012 Nov.
Artículo en Zh | MEDLINE | ID: mdl-23208144

RESUMEN

On-farm conservation and utilization of crop landraces have been proposed as means of conserving plant germplasm, in contrast to ex situ germplasm conservation, but little is known about the effectiveness of this approach. This paper reports the findings from a survey conducted in 15 unique ethnic groups of the Yunnan Province on the conservation and utilization of paddy rice, wheat (including wheat, barley, oats, and rye) and maize landrace varieties through participatory rural appraisal (PRA) and questionnaires. The surveyed regions covered 306 villages (the village group) from 237 administrative villages in 124 towns (township) distributed in 36 counties of 11 prefectures (city) in Yunnan Province. The survey showed that 44.8%, 77.5%, and 37.3% of the visited villages had lost their paddy rice, wheat, and maize landraces, respectively. A total of 901 landraces were collected, including 371 rice, 119 wheat, and 411 maize varieties, respectively. There were 2.9 on-farm varieties on average per village, 3.3, 8.0 and 5.2 varieties on average per 100 households, 1 000 peasants and 100 Ha farmland areas, respectively. Among the 306 villages, two villages (Laomian and Qingkou) maintained the highest crop diversity with 18 varieties (including 10 rice and 8 maize varieties) and 14 paddy rice varieties. Also, on-farm varieties in different ethnic groups varied significantly from each other, ranging from 16 to 120 varieties per group. The diversity of paddy rice varieties was the highest, ranging from 1 to 72, and the diversity was mainly distributed in southern, southwest Yunnan of tropical, subtropical ethnic regions. The wheat varieties ranged from 0 to 47 and distributed in northern, northwest Yunnan of high altitude, temperature, and cold ethnic regions. The maize varieties ranged from 4 to 40. These patterns of variation in on-farm varieties are directly associated with traditional culture and custom for the ethnic minorities and reflect the lack of improved varieties for the local special environments. These findings confirm the role of on-farm conservation in plant genetic resources in China and provide baseline information for better on-farm conservation and utilization of plant germplasm in China.


Asunto(s)
Productos Agrícolas/genética , Oryza/genética , Triticum/genética , Zea mays/genética , China/etnología
11.
Yi Chuan ; 34(1): 87-94, 2012 Jan.
Artículo en Zh | MEDLINE | ID: mdl-22306877

RESUMEN

To reveal the genetic variation of rice paddy landraces across 30 years, we compared the genetic variation of between 6 paddy rice landraces grown in Yuanyang Hani's terraced fields in Yuanyang County, Yunnan Province in the 1970s (past-grown landraces) and 6 paired ones that have been grown during the past decade (current-grown landraces) using 60 SSR markers. The results showed that one to four alleles were amplified in 60 loci and 159 alleles in all the landraces tested. The number of alleles from the current-grown landraces decreased by 7 alleles compared to the past-grown landraces. The average number of alleles (Na), effective number of alleles (Ne), locus polymorphism information content (PIC), and genotype diversity (H') of the past-grown landraces were higher than those of the current-grown landraces, with Na of 2.567>2.450, Ne of 2.052>1.968, PIC of 0.469>0.439, and H' of 0.768>0.722. The average genetic similarity coefficient (GS) of the past-grown landraces was 0.437 with a range from 0.200 to 0.700 based on the 60 SSR markers, and the average GS of the current-grown landraces was 0.473 with a range from 0.117 to 0.667. In conclusion, the genetic diversity in current-grown landraces was decreased compared to the past-grown landraces, and the degree of variation in some of the allele locus varied in different rice landraces as a result of 30 years' natural and artificial selection.


Asunto(s)
Variación Genética , Repeticiones de Microsatélite , Oryza/genética , China , ADN de Plantas/genética , Oryza/clasificación , Filogenia , Selección Genética
12.
Front Psychol ; 12: 600218, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33603699

RESUMEN

To effectively improve the efficiency of international service design talent training and make it more in line with society's needs, we analyze the current status of international service design talent training and its professional training focus. Based on the above problems, from the perspective of cognitive psychology, artificial intelligence and human-computer interaction (HCI) technology are used to construct the international service design talent training mode of the HCI intelligent service robot. This mode can be used to solve the existing teaching problems by using novel means to ensure the quality of teaching. Finally, through the actual analysis of teaching cases, the effectiveness of the proposed talent training mode is verified. The HCI system is based on knowledge of cognitive psychology. According to the characteristics and functions of an educational robot, the robot is combined with traditional teaching activities, and the robot-assisted talent training mode is designed. Robot-assisted talent training is a feasible training method that can improve the efficiency of talent training. Students have confidence in their learning skills before the course, and the confidence is further strengthened after the end of the course. After the course, the students have a stronger sense of cooperation. This study can provide theoretical ideas for the research of international service talent training mode.

13.
J BUON ; 26(2): 345-352, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34076978

RESUMEN

PURPOSE: The purpose of this study was to illustrate the role of long non-coding RNA (lncRNA) NEAT1 in inhibiting sorafenib sensitivity in non-small cell lung cancer (NSCLC) through targeting microRNA-335 (miR-335)/c-Met axis. METHODS: Regulatory effects of NEAT1/miR-335/c-Met axis on proliferative ability of sorafenib-induced A549 and PC9 cells were assessed by cell counting kit-8 (CCK-8) and colony formation assay. Apoptosis changes influenced by nuclear paraspeckle assembly transcript 1 (NEAT1)/miR-335/c-Met axis after sorafenib treatment in lung cancer cells were examined by detecting apoptotic rate, as well as relative levels of Bcl-2 and Bax. The interaction among NEAT1/miR-335/c-Met was analyzed through dual-luciferase reporter gene assay. RESULTS: Sorafenib treatment in A549 cells and PC9 cells attenuated the proliferation and induced apoptosis, which were more pronounced after silencing of NEAT1. MiR-335 was the downstream target of NEAT1, and its level was negatively regulated by NEAT1. Moreover, c-Met was the target gene of MiR -335. Rescue experiments verified the role of NEAT1/ MiR-335/c-Met regulatory loop in reducing the proliferative ability and inducing apoptosis of sorafenib-treated lung cancer cells. CONCLUSIONS: LncRNA NEAT1 aggravates sorafenib resistance in NSCLC through inhibiting MiR-335 to upregulate c-Met level, manifesting as attenuated proliferation and accelerated apoptosis.


Asunto(s)
Carcinoma de Pulmón de Células no Pequeñas/tratamiento farmacológico , Resistencia a Antineoplásicos/inmunología , Neoplasias Pulmonares/tratamiento farmacológico , MicroARNs/metabolismo , Proteínas Proto-Oncogénicas c-met/metabolismo , ARN Largo no Codificante/metabolismo , Sorafenib/farmacología , Carcinoma de Pulmón de Células no Pequeñas/genética , Carcinoma de Pulmón de Células no Pequeñas/metabolismo , Humanos , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/metabolismo
14.
Talanta ; 234: 122680, 2021 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-34364480

RESUMEN

Uracil DNA glycosylase (UDG) is a key base excision repair (BER) enzyme and its abnormal expression is nearly relevant to several diseases including cancer. The sensitive detection of UDG activity is beneficial for biomedical studies and clinic diagnosis. In this work, we proposed a dumbbell probe mediated triple cascade signal amplification strategy for sensitive and specific detection of UDG activity. The specially designed dumbbell probe contained two uracil bases, two recognition sites for nicking enzyme and a split sequence of DNAzyme. Unsealed dumbbell probes were first connected into sealed dumbbell probes by T4 DNA ligase, and then the unsealed probes were hydrolyzed by exonuclease to ensure the purity of probes. Under the influence of UDG, two uracil bases were removed to produce two apyrimidinic (AP) sites, which were subsequently cleaved by Endo.IV. The probes after cleavage acted as primers and templates for double nicking sites strand displacement amplification (SDA) to produce a mass of two products. The products of SDA continued to act as primers and templates for rolling circle amplification (RCA) to produce repeats containing complete DNAzyme sequences. The DNAzyme repeatedly cleaved multiple molecular beacons (MB), resulting in remarkable fluorescence enhancement. Benefiting from the triple cascade signal amplification, the sensitivity was improved and the detection limit was 7.2 × 10-5 U mL-1. The method could well distinguish UDG from other interfering enzymes and detect UDG activity in real biological samples, showing good specificity. In addition, this method could be used for screening inhibitors. The above results suggested that the method provided a promising analytical means for UDG related biomedical research and clinic diagnosis.


Asunto(s)
ADN Catalítico , Uracil-ADN Glicosidasa , Reparación del ADN , Fluorescencia , Humanos , Uracilo , Uracil-ADN Glicosidasa/metabolismo
15.
Rice (N Y) ; 14(1): 54, 2021 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-34131824

RESUMEN

BACKGROUND: Understanding and identifying the factors responsible for genetic differentiation is of fundamental importance for efficient utilization and conservation of traditional rice landraces. In this study, we examined the spatial genetic differentiation of 594 individuals sampled from 28 locations in Yunnan Province, China, covering a wide geographic distribution and diverse growing conditions. All 594 accessions were studied using ten unlinked target genes and 48 microsatellite loci, and the representative 108 accessions from the whole collection were sampled for resequencing. RESULTS: The genetic diversity of rice landraces was quite different geographically and exhibited a geographical decline from south to north in Yunnan, China. Population structure revealed that the rice landraces could be clearly differentiated into japonica and indica groups, respectively. In each group, the rice accessions could be further differentiated corresponded to their geographic locations, including three subgroups from northern, southern and middle locations. We found more obvious internal geographic structure in the japonica group than in the indica group. In the japonica group, we found that genetic and phenotypic differentiation were strongly related to geographical distance, suggesting a pattern of isolation by distance (IBD); this relationship remained highly significant when we controlled for environmental effects, where the likelihood of gene flow is inversely proportional to the distance between locations. Moreover, the gene flow also followed patterns of isolation by environment (IBE) whereby gene flow rates are higher in similar environments. We detected 314 and 216 regions had been differentially selected between Jap-N and Jap-S, Ind-N and Ind-S, respectively, and thus referred to as selection signatures for different geographic subgroups. We also observed a number of significant and interesting associations between loci and environmental factors, which implies adaptation to local environment. CONCLUSIONS: Our findings highlight the influence of geographical isolation and environmental heterogeneity on the pattern of the gene flow, and demonstrate that both geographical isolation and environment drives adaptive divergence play dominant roles in the genetic differentiation of the rice landraces in Yunnan, China as a result of limited dispersal.

16.
Plant Biotechnol J ; 7(8): 763-77, 2009 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-19754836

RESUMEN

Proteins belonging to the newly identified Cerato-platanin (CP) family have been shown to have elicitor activity in inducing disease resistance responses in various plants. In this study, we characterized a gene, MgSM1, from Magnaporthe grisea, encoding a putative small protein belonging to the CP family. MgSM1 was constitutively expressed not only in different fungal growth stages but also during its infection process in rice plants. Agrobacterium-mediated transient expression of MgSM1 in Arabidopsis resulted in hypersensitive response in the infiltrated local leaves and enhanced disease resistance against Botrytis cinerea and Pseudomonas syringae pv. tomato (Pst) DC3000 in upper leaves of plants, accompanyed by up-regulated expression of defense genes (PR-1, PR-5 and PDF1.2). Transgenic Arabidopsis plants expressing MgSM1 under control of a dexamethasone (DEX)-inducible promoter were generated. Expression of MgSM1 in transgenic plants was induced by exogenous application of DEX. MgSM1-expressing plants showed normal growth with application of <10 microm DEX. After DEX induction, the MgSM1-expressing plants showed enhanced disease resistance against B. cinerea, Alternaria brassicicola and Psto DC3000 as well as up-regulated expression of some of defense genes. Moreover, accumulation of reactive oxygen species was observed in MgSM1-expressing plants. These results collectively suggest that ectopic expression of MgSM1 in transgenic plants confers broad-spectrum resistance against different types of pathogens. Our study also provides a novel strategy to generate environment-friendly crops with enhanced broad-spectrum resistance through ectopic expression of microbe-derived disease resistance-inducing proteins.


Asunto(s)
Arabidopsis/metabolismo , Proteínas Fúngicas/metabolismo , Inmunidad Innata , Magnaporthe/genética , Secuencia de Aminoácidos , Arabidopsis/genética , Arabidopsis/inmunología , Proteínas Fúngicas/genética , Regulación de la Expresión Génica de las Plantas , Genes Fúngicos , Datos de Secuencia Molecular , Enfermedades de las Plantas/genética , Enfermedades de las Plantas/inmunología , Hojas de la Planta/genética , Hojas de la Planta/inmunología , Hojas de la Planta/metabolismo , Plantas Modificadas Genéticamente/genética , Plantas Modificadas Genéticamente/inmunología , Plantas Modificadas Genéticamente/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Alineación de Secuencia , Transformación Genética
17.
Gene ; 420(1): 57-65, 2008 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-18571878

RESUMEN

Serine carboxypeptidase-like proteins (SCPLs) comprise a large family of protein hydrolyzing enzymes that play roles in multiple cellular processes. During the course of study aimed at elucidating the molecular basis of induced immunity in rice, a gene, OsBISCPL1, encoding a putative SCPL, was isolated and identified. OsBISCPL1 contains a conserved peptidase S10 domain, serine active site and a signal peptide at N-terminus. OsBISCPL1 is expressed ubiquitously in rice, including roots, stems, leaves and spikes. Expression of OsBISCPL1 in leaves was significantly up-regulated after treatments with benzothiadiazole, salicylic acid, jasmonic acid and 1-amino cyclopropane-1-carboxylic acid, and also up-regulated in incompatible interactions between rice and the blast fungus, Magnaporthe grisea. Transgenic Arabidopsis plants with constitutive expression of OsBISCPL1 were generated and disease resistance assays indicated that the OsBISCPL1-overexpressing plants showed an enhanced disease resistance against Pseudomonas syringae pv. tomato and Alternaria brassicicola. Expression levels of defense-related genes, e.g. PR1, PR2, PR5 and PDF1.2, were constitutively up-regulated in transgenic plants as compared with those in wild-type plants. Furthermore, the OsBISCPL1-overexpressing plants also showed an increased tolerance to oxidative stress and up-regulated expression of oxidative stress-related genes. The results suggest that the OsBISCPL1 may be involved in regulation of defense responses against pathogen infection and oxidative stress.


Asunto(s)
Carboxipeptidasas/genética , Inmunidad Innata/inmunología , Oryza/inmunología , Estrés Oxidativo , Enfermedades de las Plantas/inmunología , Secuencia de Aminoácidos , Arabidopsis/genética , Regulación de la Expresión Génica de las Plantas , Magnaporthe , Datos de Secuencia Molecular , Plantas Modificadas Genéticamente , Regulación hacia Arriba
18.
Physiol Plant ; 134(3): 440-52, 2008 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-18573188

RESUMEN

F-box proteins play important roles in plant growth/development and responses to environmental stimuli through targeting substrates into degradation machinery. A rice defense-related F-box protein gene, OsDRF1, was cloned and identified during a course of study aimed at elucidating the molecular basis of induced immunity in rice. OsDRF1 encodes a protein of 328 amino acids, containing a highly conserved F-box domain. Expression of OsDRF1 was induced upon treatment with benzothiadiazole (BTH), a chemical inducer of defense responses in rice. Moreover, in BTH-treated rice seedlings, expression of OsDRF1 was further induced by infection with Magnaporthe grisea, the rice blast fungus, compared with those in water-treated seedlings. OsDRF1 was also upregulated in rice seedlings after treatment with ABA. Overexpression of OsDRF1 in transgenic tobacco resulted in enhanced disease resistance against tomato mosaic virus (ToMV) and Pseudomonas syringae pv. tabaci and strengthened expression of defense-related genes after salicylic acid treatment or ToMV infection. Root elongation of the OsDRF1-overexpressing transgenic seedlings was significantly inhibited by ABA, indicating that overexpression of OsDRF1 resulted in increased ABA sensitivity. The results suggest that OsDRF1 plays a role in disease resistance via upregulating defense-related gene expression and that OsDRF1 may also be involved in the response to ABA.


Asunto(s)
Proteínas F-Box/genética , Regulación de la Expresión Génica de las Plantas , Nicotiana/genética , Nicotiana/inmunología , Oryza/genética , Enfermedades de las Plantas/inmunología , Proteínas de Plantas/genética , Ácido Abscísico/farmacología , Secuencia de Aminoácidos , Secuencia de Bases , Clonación Molecular , Proteínas F-Box/química , Proteínas F-Box/metabolismo , Regulación de la Expresión Génica de las Plantas/efectos de los fármacos , Genes de Plantas , Inmunidad Innata/genética , Datos de Secuencia Molecular , Oryza/efectos de los fármacos , Estrés Oxidativo/efectos de los fármacos , Enfermedades de las Plantas/genética , Proteínas de Plantas/química , Proteínas de Plantas/metabolismo , Plantas Modificadas Genéticamente , Pseudomonas syringae/fisiología , Plantones/efectos de los fármacos , Plantones/genética , Análisis de Secuencia , Cloruro de Sodio/farmacología , Nicotiana/efectos de los fármacos , Nicotiana/microbiología
19.
Biochem Mol Biol Educ ; 45(3): 194-204, 2017 05.
Artículo en Inglés | MEDLINE | ID: mdl-27740737

RESUMEN

The Needleman-Wunsch algorithm has become one of the core algorithms in bioinformatics; however, this programming requires more suitable explanations for students with different major backgrounds. In supposing sample sequences and using a simple store system, the connection between the exhaustive search method and the Needleman-Wunsch algorithm was analyzed to more thoroughly explain this algorithm. The present study could benefit the teaching and learning of the Needleman-Wunsch algorithm. © 2016 by The International Union of Biochemistry and Molecular Biology, 45(3):194-204, 2017.


Asunto(s)
Algoritmos , Biología Computacional/educación , Alineación de Secuencia/métodos , Humanos
20.
Sci Rep ; 7: 41037, 2017 01 20.
Artículo en Inglés | MEDLINE | ID: mdl-28106116

RESUMEN

Potential of MoSM1, encoding for a cerato-platanin protein from Magnaporthe oryzae, in improvement of rice disease resistance was examined. Transient expression of MoSM1 in rice leaves initiated hypersensitive response and upregulated expression of defense genes. When transiently expressed in tobacco leaves, MoSM1 targeted to plasma membrane. The MoSM1-overexpressing (MoSM1-OE) transgenic rice lines showed an improved resistance, as revealed by the reduced disease severity and decreased in planta pathogen growth, against 2 strains belonging to two different races of M. oryzae, causing blast disease, and against 2 strains of Xanthomonas oryzae pv. oryzae, causing bacterial leaf blight disease. However, no alteration in resistance to sheath blight disease was observed in MoSM1-OE lines. The MoSM1-OE plants contained elevated levels of salicylic acid (SA) and jasmonic acid (JA) and constitutively activated the expression of SA and JA signaling-related regulatory and defense genes. Furthermore, the MoSM1-OE plants had no effect on drought and salt stress tolerance and on grain yield. We conclude that MoSM1 confers a broad-spectrum resistance against different pathogens through modulating SA- and JA-mediated signaling pathways without any penalty on abiotic stress tolerance and grain yield, providing a promising potential for application of MoSM1 in improvement of disease resistance in crops.


Asunto(s)
Resistencia a la Enfermedad , Proteínas Fúngicas/metabolismo , Magnaporthe/fisiología , Oryza/metabolismo , Oryza/microbiología , Enfermedades de las Plantas/microbiología , Ciclopentanos/metabolismo , Regulación de la Expresión Génica de las Plantas , Oryza/genética , Oxilipinas/metabolismo , Enfermedades de las Plantas/genética , Hojas de la Planta/metabolismo , Hojas de la Planta/microbiología , Plantas Modificadas Genéticamente , Ácido Salicílico/metabolismo , Nicotiana/metabolismo , Nicotiana/microbiología
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA