Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 50
Filtrar
1.
J Exp Bot ; 74(6): 2016-2028, 2023 03 28.
Artículo en Inglés | MEDLINE | ID: mdl-36575905

RESUMEN

Beneficial interactions between plant roots and Trichoderma species lead to both local and systemic enhancements of the plant immune system through a mechanism known as priming of defenses. Previously, we have reported a number of genes and proteins that are differentially regulated in distant tissues of maize plants following inoculation with Trichoderma atroviride. To further investigate the mechanisms involved in the systemic activation of plant responses, here we have further evaluated the regulatory aspects of a selected group of genes when priming is triggered in maize plants. Time-course experiments from the beginning of the interaction between T. atroviride and maize roots followed by leaf infection with Colletotrichum graminicola allowed us to identify a gene set regulated by priming in the leaf tissue. In the same experiment, phytohormone measurements revealed a decrease in jasmonic acid concentration while salicylic acid increased at 2 d and 6 d post-inoculation. In addition, chromatin structure and modification assays showed that chromatin was more open in the primed state compared with unprimed control conditions, and this allowed for quicker gene activation in response to pathogen attack. Overall, the results allowed us to gain insights on the interplay between the phytohormones and epigenetic regulatory events in the systemic and long-lasting regulation of maize plant defenses following Trichoderma inoculation.


Asunto(s)
Trichoderma , Zea mays , Zea mays/genética , Zea mays/metabolismo , Trichoderma/genética , Trichoderma/metabolismo , Ácido Salicílico/metabolismo , Hojas de la Planta/metabolismo , Enfermedades de las Plantas/genética , Raíces de Plantas/metabolismo
2.
urol. colomb. (Bogotá. En línea) ; 31(1): 41-42, 15/03/2022.
Artículo en Español | LILACS, COLNAL | ID: biblio-1368852

RESUMEN

Los agentes antifibrinolíticos, como el ácido tranexámico, por medio de su administración endovenosa se usan en distintos procedimientos quirúrgicos para prevenir la pérdida de sangrado perioperatorio.[1] Este medicamento es un derivado sintético análogo de la lisina que bloquea los sititos de unión de la lisina en el plasminógeno, inhibiendo su conversión a plasmina e interfiriendo en la fibrinólisis.[2] La aplicación del ácido tranexámico para disminuir el riesgo de sangrado ha sido utilizado en procedimientos urológicos como la resección transuretral prostática (RTUP), prostatectomía radical y nefrolitotomía percutánea (NLP),[3] [4] [5] también se emplea para disminuir las hematurias persistentes en pacientes con poliquistosis renal y en otras hematurias macroscópicas de origen urológico.


Antifibrinolytic agents, such as tranexamic acid, by intravenous administration are used in various surgical procedures to prevent perioperative bleeding loss.[1] This drug is a synthetic lysine analog derivative that blocks the lysine binding sites on plasminogen, inhibiting its conversion to plasmin and interfering with fibrinolysis.[2] The application of tranexamic acid to reduce the risk of bleeding has been used in urological procedures such as transurethral resection of the prostate (TURP), radical prostatectomy and nephrolithotomy. The application of tranexamic acid to reduce the risk of bleeding has been used in urological procedures such as transurethral resection of the prostate (TURP), radical prostatectomy and percutaneous nephrolithotomy (PNL),[3] [4] [5] it is also used to reduce persistent hematuria in patients with polycystic kidney disease and other macroscopic hematuria of urological origin.


Asunto(s)
Humanos , Masculino , Plasminógeno , Procedimientos Quirúrgicos Operativos , Fibrinolisina , Resección Transuretral de la Próstata , Nefrolitotomía Percutánea , Antifibrinolíticos , Prostatectomía , Ácido Tranexámico , Preparaciones Farmacéuticas , Administración Intravenosa , Enfermedades Renales Poliquísticas , Lisina
3.
J Endod ; 48(2): 223-233, 2022 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-34848251

RESUMEN

INTRODUCTION: This study assessed the prevalence of radix entomolaris and 2 canals at the distal aspect of mandibular first molars among different geographic regions by means of cone-beam computed tomographic imaging. METHODS: Precalibrated observers from 23 worldwide geographic locations followed a standardized screening protocol to assess 5750 cone-beam computed tomographic images of mandibular first molars (250 per region), gathering demographic data and recording the presence of radix entomolaris and a second canal at the distal aspect of teeth. Intra- and interrater reliability tests were conducted and comparisons among groups were performed using proportions and odds ratio forest plots. The significance level was set at 5%. RESULTS: The results of intra- and interrater tests were above 0.79. The prevalence of radix entomolaris varied from 0.9% in Venezuela (95% confidence interval [CI], 0%-1.9%) to 22.4% in China (95% CI, 17.2%-27.6%). Regarding the proportion of a second distal canal, it ranged from 16.4% in Venezuela (95% CI, 11.8%-21.0%) to 60.0% in Egypt (95% CI, 53.9%-66.1%). The East Asia subgroup was associated with a significantly higher prevalence of an extra distolingual root, whereas the American subgroup, the American native ethnic group, and elderly patients were linked to significantly lower percentages of a second canal at the distal aspect of teeth. No significant differences were noted between male or female patients. CONCLUSIONS: The overall worldwide prevalence rates of radix entomolaris and a second canal at the distal aspect of the mandibular first molar were 5.6% and 36.9%, respectively. The East Asia geographic region and Asian ethnic group had a higher prevalence of a second distal root.


Asunto(s)
Cavidad Pulpar , Mandíbula , Anciano , Tomografía Computarizada de Haz Cónico , Estudios Transversales , Femenino , Humanos , Masculino , Mandíbula/diagnóstico por imagen , Diente Molar/diagnóstico por imagen , Reproducibilidad de los Resultados , Raíz del Diente/diagnóstico por imagen
4.
Planta ; 253(5): 115, 2021 May 02.
Artículo en Inglés | MEDLINE | ID: mdl-33934226

RESUMEN

MAIN CONCLUSION: Trichoderma activates plant proteins to counteract Fusarium infection. Comparison between proteomic and transcriptomic data suggests differential response regulation. Proteins from the phenylpropanoid pathway are activated to quickly respond to pathogen attack. Trichoderma species can stimulate local and distant immune responses in colonized plant tissues to prevent future pathogenic attacks. Priming of plant defenses is characterized by changes in transcriptional, metabolic, and epigenetic states after stimulus perception. We have previously investigated transcriptional reprogramming in silk tissues from maize plants inoculated with Trichoderma atroviride and challenged with Fusarium verticillioides (Agostini et al., Mol Plant-Microbe In 32:95-106, 2019). To better understand the molecular changes induced by T. atroviride in maize, a proteomic approach was conducted in this instance. Several proteins belonging to different metabolic categories were detected as priming-involved proteins. However, we detected a very low correlation with those priming-modulated transcripts suggesting the importance of regulatory events a posteriori of the transcriptional process to accomplish the final goal of blocking pathogen entry. Specifically, we focused on the phenylpropanoid pathway, since we detected several proteins that are upregulated in the priming state and might explain cell wall reinforcement as well as the increase in flavonoid and lignin content in maize silks after activation of induced systemic resistance.


Asunto(s)
Trichoderma , Zea mays , Fusarium , Hypocreales , Enfermedades de las Plantas , Proteoma , Proteómica , Seda
5.
J Endod ; 47(8): 1253-1264, 2021 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-33901542

RESUMEN

INTRODUCTION: The presence of multiple root canals is an important morphologic aspect of mandibular premolars. This study aimed to perform a worldwide analysis on the prevalence of a lingual canal in mandibular premolars and to evaluate its influence on patients' demographics in 23 countries using cone-beam computed tomographic images. METHODS: Observers from 23 countries were instructed to evaluate cone-beam computed tomographic images of 300 first and 300 second premolars (13,800 teeth) regarding the presence of a lingual canal, canal configuration, and data related to patients' ethnicity, age, and sex following a standardized screening methodology. Intra- and interrater evaluations were performed using the Cohen kappa test and intraclass correlation coefficient. Proportion and odds ratio forest plots were calculated in order to compare groups. Statistical significance was set at 5%. RESULTS: Both kappa and intraclass correlation coefficient values were above 0.60, and the percentage of agreement was 94.9% (first premolar) and 97.8% (second premolar). A significant statistical difference was observed between the worldwide proportion of a lingual canal in mandibular first (23.8%; range, 12.0%-32.7%) and second (5.3%; range, 1.0%-15.3%) premolars (P < .05). Asians and patients over 60 years old were associated with the lowest proportions of a lingual canal (P < .05), whereas Africans and younger groups were associated with the highest proportions (P < .05). The prevalence of a lingual canal in males (27.9%) was higher than females (20.0%) for the first premolar only (P < .05). Males were associated with 1.533 and 1.597 higher odds of presenting a lingual root canal in the first and second premolars, respectively. CONCLUSIONS: The worldwide proportion of a lingual root canal was 23.6% and 5.3% for the first and second premolars, respectively. Ethnicity, geographic region, age, and sex had an influence on the outcomes.


Asunto(s)
Cavidad Pulpar , Raíz del Diente , Diente Premolar/diagnóstico por imagen , Tomografía Computarizada de Haz Cónico , Estudios Transversales , Cavidad Pulpar/diagnóstico por imagen , Femenino , Humanos , Masculino , Mandíbula/diagnóstico por imagen , Persona de Mediana Edad , Estudios Multicéntricos como Asunto , Prevalencia
6.
Respir Physiol Neurobiol ; 287: 103620, 2021 05.
Artículo en Inglés | MEDLINE | ID: mdl-33515749

RESUMEN

In 15 pulmonary arterial hypertension patients, the relation of functional capacity to their peripheral endothelial function and sympathaovagal modulation was studied by carrying out brachial artery ultrasound and electrocardiogram spectral analysis, respectively. The functional capacity was assessed by cardiopulmonary exercise testing and six-minute walking test. The sympathovagal modulation was correlated with the predicted peak oxygen consumption (peak VO2 %; r = 0.692, P < 0.05), peak O2 pulse (mL/beat; r = 0.661, P < 0.05), VE, minute ventilation, VCO2 carbon dioxide production (VE/VCO2 slope; r=-0.806, P < 0.01) and distance walked predicted (%6MWT; r = 0.694, P < 0.05). Moreover, there were negative correlations between parasympathetic modulation with peak VO2 (r = 0.755, P < 0.01), peak VO2% (r=-0.727, P < 0.01) and peak O2 pulse (r = 0.615, P < 0.05), %6MWT (r=-0.834, P < 0.01). Collectively these correlations indicate that parasympathetic withdrawal is crucial for improving functional capacity. This conclusion is supported by both positive and negative correlations of parasympathetic modulation with the functional capacity parameters. The sympathetic modulation predominance, although increases the cardiovascular risk, is probably crucial to facilitate the bronchodilation and the oxygen uptake.


Asunto(s)
Sistema Nervioso Parasimpático/fisiopatología , Hipertensión Arterial Pulmonar/fisiopatología , Sistema Nervioso Simpático/fisiopatología , Adulto , Electrocardiografía , Prueba de Esfuerzo , Femenino , Insuficiencia Cardíaca/fisiopatología , Humanos , Masculino , Persona de Mediana Edad
7.
Arq Bras Cardiol ; 115(1): 52-58, 2020 07.
Artículo en Inglés, Portugués | MEDLINE | ID: mdl-32785491

RESUMEN

Background The family history of hypertension (FHH) imposes consistent risk for diverse chronic diseases that are accompanied by hypertension. Furthermore, the heart rate variability (HRV) and flow-mediated dilation (FMD) are both related to maximal oxygen uptake (VO2max), and are usually impaired during hypertension Objective To compare the autonomic modulation, the endothelial function (EF) and maximum oxygen uptake (VO2max) of young athletes, separated according to their parents' blood pressure (BP) history, in order to study the influence of their genetic background on those parameters. Methods A total of 46 young male soccer players (18±2 years of age) were divided into four groups: 1-normotensive father and mother (FM-N); 2-only father was hypertensive (F-H); 3-only mother was hypertensive (M-H); 4-father and mother were hypertensive (FM-H). Measurements of BP, FMD, HRV and VO2maxwere performed. The significance level adopted in the statistical analysis was 5%. Results The standard deviation of normal RR intervals (SDNN; FM-N=314±185; FM-H=182.4± 57.8), the square root of the mean squared differences in successive RR intervals (RMSSD; FM-N=248±134; FM-H=87±51), the number of interval differences of successive NN intervals greater than 50ms (NN50; FM-N=367±83.4; FM-H=229±55), the ratio derived by dividing NN50 by the total number of NN intervals (pNN50; FM-N=32.4±6.2; FM-H=21.1±5.3) and the high (HF; FM-N=49±8.9; FM-H=35.3±12) and low-frequency (LF; FM-N=50.9±8.9; FM-H=64.6±12) components, in normalized units (%), were significantly lower in the FM-H group than in the FM-N group (p<0.05). On the other hand, the LF/HF ratio (ms2) was significantly higher (p<0.05). We found no significant difference between the groups in VO2maxand FMD (p<0.05). Conclusions In young male soccer players, the FHH plays a potentially role in autonomic balance impairment, especially when both parents are hypertensive, but present no changes in VO2maxand FMD. In this case, there is a decrease in the sympathetic-vagal control, which seems to precede the endothelial damage (Arq Bras Cardiol. 2020; 115(1):52-58).


Asunto(s)
Endotelio/fisiología , Hipertensión , Fútbol , Adolescente , Adulto , Sistema Nervioso Autónomo/fisiopatología , Frecuencia Cardíaca , Humanos , Hipertensión/genética , Masculino , Oxígeno , Consumo de Oxígeno , Adulto Joven
8.
Arq. bras. cardiol ; 115(1): 52-58, jul. 2020. tab, graf
Artículo en Portugués | LILACS, Sec. Est. Saúde SP | ID: biblio-1131252

RESUMEN

Resumo Fundamento A história familiar de hipertensão (HFH) é um fator de risco consistente para diversas doenças crônicas que são acompanhadas por hipertensão. Além disso, a variabilidade da frequência cardíaca (VFC) e a vasodilatação mediada pelo fluxo (VMF), ambas relacionadas ao consumo máximo de oxigênio (VO2max), são geralmente prejudicadas durante a hipertensão. Objetivo Comparar a modulação autonômica, a função endotelial (FE) e o consumo máximo de oxigênio (VO2max) de jovens atletas, separados de acordo com a história de pressão arterial (PA) dos seus pais, a fim de investigar a influência da ascendência genética nesses parâmetros. Métodos Quarenta e seis jovens jogadores de futebol do sexo masculino (18±2 anos) foram divididos em quatro grupos: 1- pai e mãe normotensos (FM-N); 2- apenas pai hipertenso (F-H); 3- apenas mãe hipertensa (M-H); 4- pai e mãe hipertensos (FM-H). Foram realizadas medições da PA, VMF, VFC e do VO2max. Na análise estatística, foi adotado o nível de significância de 5%. Resultados O desvio padrão dos intervalos RR normais (SDNN; FM-N=314±185; FM-H=182,4± 57,8), a raiz quadrada das médias quadráticas das diferenças dos intervalos R-R sucessivos (RMSSD; FM-N=248±134; FM-H=87±51), o número de diferenças entre intervalos NN sucessivos maiores que 50 ms (NN50; FM-N=367±83,4; FM-H=229±55), a proporção de NN50 dividida pelo número total de NNs (pNN50; FM-N=32,4±6,2; FM-H=21,1±5,3) e os componentes de alta (HF; FM-N=49±8,9; FM-H=35,3±12) e baixa frequência (LF; FM-N=50,9±8,9; FM-H=64,6±12), em unidades normalizadas (%), foram significativamente mais baixos no grupo FM-H do que no grupo FM-N (p<0,05). Por outro lado, a relação LF/HF (ms2) foi significativamente maior (p<0,05). Não foram encontradas diferenças significativas no VO2max e na VMF entre os grupos (p<0,05). Conclusão Em jovens jogadores de futebol do sexo masculino, a HFH desempenha um papel potencialmente importante no comprometimento do balanço autonômico, principalmente quando ambos os pais são hipertensos, mas não apresentam alterações no VO2max e na VMF. Nesse caso, há uma diminuição no controle simpatovagal, que parece preceder o dano endotelial. (Arq Bras Cardiol. 2020; 115(1):52-58)


Abstract Background The family history of hypertension (FHH) imposes consistent risk for diverse chronic diseases that are accompanied by hypertension. Furthermore, the heart rate variability (HRV) and flow-mediated dilation (FMD) are both related to maximal oxygen uptake (VO2max), and are usually impaired during hypertension Objective To compare the autonomic modulation, the endothelial function (EF) and maximum oxygen uptake (VO2max) of young athletes, separated according to their parents' blood pressure (BP) history, in order to study the influence of their genetic background on those parameters. Methods A total of 46 young male soccer players (18±2 years of age) were divided into four groups: 1-normotensive father and mother (FM-N); 2-only father was hypertensive (F-H); 3-only mother was hypertensive (M-H); 4-father and mother were hypertensive (FM-H). Measurements of BP, FMD, HRV and VO2maxwere performed. The significance level adopted in the statistical analysis was 5%. Results The standard deviation of normal RR intervals (SDNN; FM-N=314±185; FM-H=182.4± 57.8), the square root of the mean squared differences in successive RR intervals (RMSSD; FM-N=248±134; FM-H=87±51), the number of interval differences of successive NN intervals greater than 50ms (NN50; FM-N=367±83.4; FM-H=229±55), the ratio derived by dividing NN50 by the total number of NN intervals (pNN50; FM-N=32.4±6.2; FM-H=21.1±5.3) and the high (HF; FM-N=49±8.9; FM-H=35.3±12) and low-frequency (LF; FM-N=50.9±8.9; FM-H=64.6±12) components, in normalized units (%), were significantly lower in the FM-H group than in the FM-N group (p<0.05). On the other hand, the LF/HF ratio (ms2) was significantly higher (p<0.05). We found no significant difference between the groups in VO2maxand FMD (p<0.05). Conclusions In young male soccer players, the FHH plays a potentially role in autonomic balance impairment, especially when both parents are hypertensive, but present no changes in VO2maxand FMD. In this case, there is a decrease in the sympathetic-vagal control, which seems to precede the endothelial damage (Arq Bras Cardiol. 2020; 115(1):52-58)


Asunto(s)
Humanos , Masculino , Adolescente , Adulto , Adulto Joven , Fútbol , Endotelio/fisiopatología , Hipertensión/genética , Oxígeno , Consumo de Oxígeno , Sistema Nervioso Autónomo/parasitología , Frecuencia Cardíaca
9.
Mol Plant Microbe Interact ; 32(1): 95-106, 2019 01.
Artículo en Inglés | MEDLINE | ID: mdl-30253116

RESUMEN

In the present study, we investigated the induced systemic resistance (ISR) activated by the beneficial fungus Trichoderma atroviride in maize plants, and the early immunological responses triggered after challenge with the ear rot pathogen Fusarium verticillioides. By transcriptional analysis, we were able to identify the gene core set specifically modulated in silks of maize plants expressing ISR. Our results showed that the main transcriptional reprogramming falls into genes involved in five main functional categories: cell structure or cell wall, amino acid and protein metabolism, stress responses, signaling, and transport. Among these ISR-related genes, it is important to highlight novel findings regarding hormone metabolism and signaling. The expression of hormone-dependent genes was in good agreement with the abscisic acid, jasmonic acid, and salicylic acid (SA) levels detected in the plants under study. The experimental design allowed the identification of novel regulatory elements related to a heightened state of defense in silks and suggests that steroids and SA are central components of a master regulatory network controlling the immunity of silks during ISR. The results presented also provide evidence about the molecular mechanisms used by maize silks against F. verticillioides to counteract pathogenic development and host invasion, including pathogenesis-related genes, plant cell-wall reinforcement, fungal cell-wall-degrading enzymes and secondary metabolism.


Asunto(s)
Ácido Salicílico , Transducción de Señal , Zea mays , Fusarium/inmunología , Regulación de la Expresión Génica de las Plantas/inmunología , Ácido Salicílico/inmunología , Transducción de Señal/inmunología , Zea mays/inmunología , Zea mays/microbiología
10.
J Endod ; 44(11): 1641-1649.e1, 2018 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-30243661

RESUMEN

INTRODUCTION: Maxillary first molar second mesiobuccal (MB2) root canal prevalence may change among different populations. The aim of this study was to analyze the worldwide prevalence of the MB2 root canal and understand its possible relation with sex, age, side, and root configuration using in vivo cone-beam computed tomographic (CBCT) assessment. METHODS: Observers from 21 regions were calibrated to achieve a similar CBCT assessment methodology and instructed to collect data from 250 maxillary first molars in previously existing examinations. Intra- and interrater reliability tests were performed. The sample size included 5250 molars and was defined by way of a preliminary trial. Data collected included MB2 presence, sex, age, side, number of roots per tooth, and mesiobuccal root configuration. The z test for proportions in independent groups was used to analyze the differences among subgroups. P < .05 was considered significant. RESULTS: The worldwide CBCT-assessed MB2 prevalence was 73.8%, ranging from 48.0% in Venezuela to 97.6% in Belgium. The prevalence in males and females was 76.3% and 71.8%, respectively (P < .05). Significantly higher MB2 proportions were found in younger patients and 3-rooted molar configurations. The group intraclass correlation coefficient and the percentage of agreement for the MB2 presence were 0.95 and 0.91, respectively. The intrarater Cohen kappa value was above 0.61 for all observers. CONCLUSIONS: MB2 prevalence in the analyzed regions varied widely. The differences may be associated with specificities within each region but also patient demographics. Males, younger patients, and 3-rooted configurations were associated with higher MB2 proportions.


Asunto(s)
Tomografía Computarizada de Haz Cónico , Cavidad Pulpar/anatomía & histología , Cavidad Pulpar/diagnóstico por imagen , Maxilar/anatomía & histología , Maxilar/diagnóstico por imagen , Diente Molar/anatomía & histología , Diente Molar/diagnóstico por imagen , Raíz del Diente/anatomía & histología , Raíz del Diente/diagnóstico por imagen , Adulto , Factores de Edad , Variación Anatómica , Femenino , Salud Global , Humanos , Masculino , Persona de Mediana Edad , Prevalencia , Factores Sexuales , Adulto Joven
11.
J Infect Dis ; 218(suppl_5): S672-S678, 2018 11 22.
Artículo en Inglés | MEDLINE | ID: mdl-29939303

RESUMEN

Background: A need to develop therapeutics to treat Ebola virus disease patients in remote and resource-challenged settings remains in the wake of the 2013-2016 epidemic in West Africa. Toward this goal, we screened drugs under consideration as treatment options and other drugs of interest, most being small molecules approved by the Food and Drug Administration. Drugs demonstrating in vitro antiviral activity were advanced for evaluation in combinations because of advantages often provided by drug cocktails. Methods: Drugs were screened for blockade of Ebola virus infection in cultured cells. Twelve drugs were tested in all (78 pair-wise) combinations, and 3 were tested in a subset of combinations. Results: Multiple synergistic drug pairs emerged, with the majority comprising 2 entry inhibitors. For the pairs of entry inhibitors studied, synergy was demonstrated at the level of virus entry into host cells. Highly synergistic pairs included aripiprazole/piperacetazine, sertraline/toremifene, sertraline/bepridil, and amodiaquine/clomiphene. Conclusions: Our study shows the feasibility of identifying pairs of approved drugs that synergistically block Ebola virus infection in cell cultures. We discuss our findings in terms of the theoretic ability of these or alternate combinations to reach therapeutic levels. Future research will assess selected combinations in small-animal models of Ebola virus disease.


Asunto(s)
Antivirales/administración & dosificación , Ebolavirus/efectos de los fármacos , Animales , Antivirales/uso terapéutico , Chlorocebus aethiops , Aprobación de Drogas , Sinergismo Farmacológico , Quimioterapia Combinada , Células Vero , Virión/efectos de los fármacos , Internalización del Virus/efectos de los fármacos
12.
Mol Plant Microbe Interact ; 29(2): 83-95, 2016 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-26554735

RESUMEN

Plant pathogens have the capacity to manipulate the host immune system through the secretion of effectors. We identified 27 putative effector proteins encoded in the genome of the maize anthracnose pathogen Colletotrichum graminicola that are likely to target the host's nucleus, as they simultaneously contain sequence signatures for secretion and nuclear localization. We functionally characterized one protein, identified as CgEP1. This protein is synthesized during the early stages of disease development and is necessary for anthracnose development in maize leaves, stems, and roots. Genetic, molecular, and biochemical studies confirmed that this effector targets the host's nucleus and defines a novel class of double-stranded DNA-binding protein. We show that CgEP1 arose from a gene duplication in an ancestor of a lineage of monocot-infecting Colletotrichum spp. and has undergone an intense evolution process, with evidence for episodes of positive selection. We detected CgEP1 homologs in several species of a grass-infecting lineage of Colletotrichum spp., suggesting that its function may be conserved across a large number of anthracnose pathogens. Our results demonstrate that effectors targeted to the host nucleus may be key elements for disease development and aid in the understanding of the genetic basis of anthracnose development in maize plants.


Asunto(s)
Transporte Activo de Núcleo Celular/fisiología , Colletotrichum/fisiología , Proteínas Fúngicas/metabolismo , Enfermedades de las Plantas/microbiología , Zea mays/microbiología , Adaptación Fisiológica , Evolución Biológica , ADN de Hongos/genética , ADN de Plantas/metabolismo , Proteínas Fúngicas/genética , Regulación Fúngica de la Expresión Génica/fisiología , Variación Genética , Genoma de Planta , Hojas de la Planta/microbiología , Raíces de Plantas/microbiología , Tallos de la Planta/microbiología , Unión Proteica
13.
Mol Plant Pathol ; 17(7): 1048-62, 2016 09.
Artículo en Inglés | MEDLINE | ID: mdl-26619206

RESUMEN

Colletotrichum graminicola causes maize anthracnose, an agronomically important disease with a worldwide distribution. We have identified a fungalysin metalloprotease (Cgfl) with a role in virulence. Transcriptional profiling experiments and live cell imaging show that Cgfl is specifically expressed during the biotrophic stage of infection. To determine whether Cgfl has a role in virulence, we obtained null mutants lacking Cgfl and performed pathogenicity and live microscopy assays. The appressorium morphology of the null mutants is normal, but they exhibit delayed development during the infection process on maize leaves and roots, showing that Cgfl has a role in virulence. In vitro chitinase activity assays of leaves infected with wild-type and null mutant strains show that, in the absence of Cgfl, maize leaves exhibit increased chitinase activity. Phylogenetic analyses show that Cgfl is highly conserved in fungi. Similarity searches, phylogenetic analysis and transcriptional profiling show that C. graminicola encodes two LysM domain-containing homologues of Ecp6, suggesting that this fungus employs both Cgfl-mediated and LysM protein-mediated strategies to control chitin signalling.


Asunto(s)
Colletotrichum/patogenicidad , Secuencia Conservada , Proteínas Fúngicas/metabolismo , Metaloproteasas/metabolismo , Enfermedades de las Plantas/microbiología , Zea mays/microbiología , Secuencia de Aminoácidos , Quitina , Colletotrichum/genética , Colletotrichum/crecimiento & desarrollo , Evolución Molecular , Proteínas Fúngicas/química , Proteínas Fúngicas/genética , Regulación Fúngica de la Expresión Génica , Genoma Fúngico , Hifa/metabolismo , Metaloproteasas/química , Metaloproteasas/genética , Microscopía Confocal , Mutación/genética , Filogenia , Hojas de la Planta/microbiología , Raíces de Plantas/citología , Raíces de Plantas/microbiología , Proteolisis , Homología de Secuencia de Ácido Nucleico , Virulencia
14.
Plant Sci ; 228: 79-87, 2014 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-25438788

RESUMEN

Cerato-platanins are an interesting group of small, secreted, cysteine-rich proteins that have been implicated in virulence of certain plant pathogenic fungi. The relatively recent discovery of these proteins in plant beneficial fungi like Trichoderma spp., and their positive role in induction of defense in plants against invading pathogens has raised the question as to whether these proteins are effectors or elicitor molecules. Here we present a comprehensive review on the occurrence of these conserved proteins across the fungal kingdom, their structure-function relationships, and their physiological roles in plant pathogenic and symbiotic fungi. We also discuss the usefulness of these proteins in evolving strategies for crop protection through a transgenic approach or direct application as elicitors.


Asunto(s)
Proteínas Fúngicas/fisiología , Plantas/microbiología , Secuencia de Aminoácidos , Proteínas Fúngicas/química , Interacciones Huésped-Patógeno , Datos de Secuencia Molecular , Control Biológico de Vectores , Relación Estructura-Actividad , Simbiosis
15.
Microbiology (Reading) ; 160(Pt 10): 2319-2330, 2014 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-25082950

RESUMEN

Using a gene disruption strategy, we generated mutants in the gliP locus of the plant-beneficial fungus Trichoderma virens that were no longer capable of producing gliotoxin. Phenotypic assays demonstrated that the gliP-disrupted mutants grew faster, were more sensitive to oxidative stress and exhibited a sparse colony edge compared with the WT strain. In a plate confrontation assay, the mutants deficient in gliotoxin production were ineffective as mycoparasites against the oomycete, Pythium ultimum, and the necrotrophic fungal pathogen, Sclerotinia sclerotiorum, but retained mycoparasitic ability against Rhizoctonia solani. Biocontrol assays in soil showed that the mutants were incapable of protecting cotton seedlings from attack by P. ultimum, against which the WT strain was highly effective. The mutants, however, were as effective as the WT strain in protecting cotton seedlings against R. solani. Loss of gliotoxin production also resulted in a reduced ability of the mutants to attack the sclerotia of S. sclerotiorum compared with the WT. The addition of exogenous gliotoxin to the sclerotia colonized by the mutants partially restored their degradative abilities. Interestingly, as in Aspergillus fumigatus, an opportunistic human pathogen, gliotoxin was found to be involved in pathogenicity of T. virens against larvae of the wax moth, Galleria mellonella. The loss of gliotoxin production in T. virens was restored by complementation with the gliP gene from A. fumigatus. We have, thus, demonstrated that the putative gliP cluster of T. virens is responsible for the biosynthesis of gliotoxin, and gliotoxin is involved in mycoparasitism and biocontrol properties of this plant-beneficial fungus.


Asunto(s)
Gliotoxina/metabolismo , Gossypium/microbiología , Enfermedades de las Plantas/microbiología , Simbiosis , Trichoderma/fisiología , Animales , Ascomicetos/crecimiento & desarrollo , Lepidópteros/microbiología , Interacciones Microbianas , Mutagénesis Insercional , Estrés Oxidativo , Control Biológico de Vectores , Pythium/crecimiento & desarrollo , Rhizoctonia/crecimiento & desarrollo , Plantones/microbiología , Microbiología del Suelo , Análisis de Supervivencia , Trichoderma/crecimiento & desarrollo , Trichoderma/metabolismo , Virulencia
16.
Am J Hypertens ; 27(4): 508-13, 2014 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-23396372

RESUMEN

BACKGROUND: Blood pressure (BP) should be kept within a narrow range to allow adequate tissue perfusion. In particular, heart-rate variability (HRV) can be used to assess autonomic cardiovascular modulation, and flow-mediated dilation (FMD) can provide valuable information about the ability of the cardiovascular system to adapt to different pressures. Our objective in the study described here was to investigate the effect of a difference of 10mm Hg in mean arterial pressure (MAP) on endothelial function and autonomic balance in young and normotensive soccer players. METHODS: Twenty-nine young male soccer players (mean age 17.7 years) were divided into two groups according to their MAP (mm Hg): MAP-84 and MAP-94. The BP, FMD, HRV and maximum oxygen uptake (VO2max) of each group were measured. RESULTS: Systolic BP (SBP) and diastolic BP (DBP) were significantly higher (P < 0.0001 and P < 0.006, respectively) in the MAP-94 group. There were no differences in VO2max and endothelial function in the two groups (P < 0.7699). However, the standard deviation (SD) of normal RR intervals (SDNN) and the square root of the mean squared differences in successive RR intervals (RMSSD) were significantly lower in the MAP-94 than in the MAP-84 group (P < 0.0001 and P < 0.005, respectively). In the MAP-94 group, both the high-and low-frequency components were significantly (P < 0.001, P < 0.021, P < 0.017, respectively) lower in both absolute and normalized units, whereas the LF/HF ratio was significantly (P < 0.012) higher. CONCLUSIONS: Collectively, our findings indicate that in young soccer players, autonomic cardiovascular modulation is impaired when MAP is increased by 10mm Hg, even within an optimal range of BP and regardless of endothelial function and VO2max.


Asunto(s)
Sistema Nervioso Autónomo/fisiopatología , Presión Sanguínea/fisiología , Frecuencia Cardíaca/fisiología , Fútbol/fisiología , Adolescente , Sistema Nervioso Autónomo/fisiología , Arteria Braquial/anatomía & histología , Arteria Braquial/diagnóstico por imagen , Sistema Cardiovascular/fisiopatología , Endotelio Vascular/fisiología , Humanos , Masculino , Flujo Sanguíneo Regional , Ultrasonografía Doppler , Vasodilatación , Adulto Joven
17.
PLoS One ; 8(3): e59078, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23554975

RESUMEN

The genus Colletotrichum contains a large number of phytopathogenic fungi that produce enormous economic losses around the world. The effect of horizontal gene transfer (HGT) has not been studied yet in these organisms. Inter-Kingdom HGT into fungal genomes has been reported in the past but knowledge about the HGT between plants and fungi is particularly limited. We describe a gene in the genome of several species of the genus Colletotrichum with a strong resemblance to subtilisins typically found in plant genomes. Subtilisins are an important group of serine proteases, widely distributed in all of the kingdoms of life. Our hypothesis is that the gene was acquired by Colletotrichum spp. through (HGT) from plants to a Colletotrichum ancestor. We provide evidence to support this hypothesis in the form of phylogenetic analyses as well as a characterization of the similarity of the subtilisin at the primary, secondary and tertiary structural levels. The remarkable level of structural conservation of Colletotrichum plant-like subtilisin (CPLS) with plant subtilisins and the differences with the rest of Colletotrichum subtilisins suggests the possibility of molecular mimicry. Our phylogenetic analysis indicates that the HGT event would have occurred approximately 150-155 million years ago, after the divergence of the Colletotrichum lineage from other fungi. Gene expression analysis shows that the gene is modulated during the infection of maize by C. graminicola suggesting that it has a role in plant disease. Furthermore, the upregulation of the CPLS coincides with the downregulation of several plant genes encoding subtilisins. Based on the known roles of subtilisins in plant pathogenic fungi and the gene expression pattern that we observed, we postulate that the CPLSs have an important role in plant infection.


Asunto(s)
Colletotrichum/genética , Transferencia de Gen Horizontal , Plantas/genética , Plantas/microbiología , Subtilisina/genética , Secuencia de Aminoácidos , Expresión Génica , Interacciones Huésped-Patógeno , Modelos Moleculares , Datos de Secuencia Molecular , Filogenia , Enfermedades de las Plantas/genética , Enfermedades de las Plantas/microbiología , Conformación Proteica , Dominios y Motivos de Interacción de Proteínas , Alineación de Secuencia , Subtilisina/química
18.
Commun Integr Biol ; 6(6): e25727, 2013 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-24563701

RESUMEN

The Colletotrichum plant-like subtilisins (CPLSs) are a family of proteins found only in species of the phytopathogenic fungus Colletotrichum. CPLSs have high similarity to plant subtilisins and our previous work has shown that they were acquired by an ancient horizontal gene transfer event from plants. The rapid growth of sequence data in public databases enabled us to reexamine the structure and evolution of the CPLSs. A new plant subtilisin structural model aided us in refining the tertiary structure of CPLSs. Also, new information about protein interactions of plant subtilisin has provided new insights into the putative function of CPLSs. The availability of new genome sequences of members of the genus Colletotrichum gave us the opportunity to further validate our hypothesis that the CPLSs are unique to the Colletotrichum lineage. Together, this information furthers our knowledge of the potential role of the CPLSs in pathogenicity and the role of HGT in the genome evolution of plant pathogenic fungi.

19.
Plant Signal Behav ; 7(12): 1667-75, 2012 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-23073005

RESUMEN

Millions of years of coevolution between plants and pathogens can leave footprints on their genomes and genes involved on this interaction are expected to show patterns of positive selection in which novel, beneficial alleles are rapidly fixed within the population. Using information about upregulated genes in maize during Colletotrichum graminicola infection and resources available in the Phytozome database, we looked for evidence of positive selection in the Poaceae lineage, acting on protein coding sequences related with plant defense. We found six genes with evidence of positive selection and another eight with sites showing episodic selection. Some of them have already been described as evolving under positive selection, but others are reported here for the first time including genes encoding isocitrate lyase, dehydrogenases, a multidrug transporter, a protein containing a putative leucine-rich repeat and other proteins with unknown functions. Mapping positively selected residues onto the predicted 3-D structure of proteins showed that most of them are located on the surface, where proteins are in contact with other molecules. We present here a set of Poaceae genes that are likely to be involved in plant defense mechanisms and have evidence of positive selection. These genes are excellent candidates for future functional validation.


Asunto(s)
Proteínas de Plantas/química , Proteínas de Plantas/metabolismo , Poaceae/metabolismo , Enfermedades de las Plantas , Proteínas de Plantas/genética , Poaceae/genética , Zea mays/genética , Zea mays/metabolismo
20.
Plant Physiol ; 158(3): 1342-58, 2012 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-22247271

RESUMEN

Hemibiotrophic plant pathogens first establish a biotrophic interaction with the host plant and later switch to a destructive necrotrophic lifestyle. Studies of biotrophic pathogens have shown that they actively suppress plant defenses after an initial microbe-associated molecular pattern-triggered activation. In contrast, studies of the hemibiotrophs suggest that they do not suppress plant defenses during the biotrophic phase, indicating that while there are similarities between the biotrophic phase of hemibiotrophs and biotrophic pathogens, the two lifestyles are not analogous. We performed transcriptomic, histological, and biochemical studies of the early events during the infection of maize (Zea mays) with Colletotrichum graminicola, a model pathosystem for the study of hemibiotrophy. Time-course experiments revealed that mRNAs of several defense-related genes, reactive oxygen species, and antimicrobial compounds all begin to accumulate early in the infection process and continue to accumulate during the biotrophic stage. We also discovered the production of maize-derived vesicular bodies containing hydrogen peroxide targeting the fungal hyphae. We describe the fungal respiratory burst during host infection, paralleled by superoxide ion production in specific fungal cells during the transition from biotrophy to a necrotrophic lifestyle. We also identified several novel putative fungal effectors and studied their expression during anthracnose development in maize. Our results demonstrate a strong induction of defense mechanisms occurring in maize cells during C. graminicola infection, even during the biotrophic development of the pathogen. We hypothesize that the switch to necrotrophic growth enables the fungus to evade the effects of the plant immune system and allows for full fungal pathogenicity.


Asunto(s)
Colletotrichum/patogenicidad , Interacciones Huésped-Patógeno , Enfermedades de las Plantas/inmunología , Zea mays/inmunología , Zea mays/microbiología , Ácido Abscísico/farmacología , Antifúngicos/metabolismo , Pared Celular/metabolismo , Ácidos Cumáricos/metabolismo , Perfilación de la Expresión Génica , Genes Fúngicos , Genes de Plantas , Peróxido de Hidrógeno/metabolismo , Hifa/inmunología , Hifa/metabolismo , Fenoles/aislamiento & purificación , Fenoles/metabolismo , Células Vegetales/inmunología , Células Vegetales/microbiología , Enfermedades de las Plantas/microbiología , Hojas de la Planta/inmunología , Hojas de la Planta/microbiología , Propionatos , Especies Reactivas de Oxígeno/metabolismo
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...