RESUMEN
BACKGROUND: Ralstonia solanacearum is the causal agent of bacterial wilt, a devastating plant disease responsible for serious economic losses especially on potato, tomato, and other solanaceous plant species in temperate countries. In R. solanacearum, gene expression analysis has been key to unravel many virulence determinants as well as their regulatory networks. However, most of these assays have been performed using either bacteria grown in minimal medium or in planta, after symptom onset, which occurs at late stages of colonization. Thus, little is known about the genetic program that coordinates virulence gene expression and metabolic adaptation along the different stages of plant infection by R. solanacearum. RESULTS: We performed an RNA-sequencing analysis of the transcriptome of bacteria recovered from potato apoplast and from the xylem of asymptomatic or wilted potato plants, which correspond to three different conditions (Apoplast, Early and Late xylem). Our results show dynamic expression of metabolism-controlling genes and virulence factors during parasitic growth inside the plant. Flagellar motility genes were especially up-regulated in the apoplast and twitching motility genes showed a more sustained expression in planta regardless of the condition. Xylem-induced genes included virulence genes, such as the type III secretion system (T3SS) and most of its related effectors and nitrogen utilisation genes. The upstream regulators of the T3SS were exclusively up-regulated in the apoplast, preceding the induction of their downstream targets. Finally, a large subset of genes involved in central metabolism was exclusively down-regulated in the xylem at late infection stages. CONCLUSIONS: This is the first report describing R. solanacearum dynamic transcriptional changes within the plant during infection. Our data define four main genetic programmes that define gene pathogen physiology during plant colonisation. The described expression of virulence genes, which might reflect bacterial states in different infection stages, provides key information on the R. solanacearum potato infection process.
Asunto(s)
Ralstonia solanacearum , Solanum lycopersicum , Enfermedades de las Plantas , Ralstonia solanacearum/genética , Virulencia/genética , Factores de Virulencia/genéticaRESUMEN
Autophagy is a major nutrient recycling mechanism in plants. However, its functional connection with programmed cell death (PCD) is a topic of active debate and remains not well understood. Our previous studies established the plant metacaspase AtMC1 as a positive regulator of pathogen-triggered PCD. Here, we explored the linkage between plant autophagy and AtMC1 function in the context of pathogen-triggered PCD and aging. We observed that autophagy acts as a positive regulator of pathogen-triggered PCD in a parallel pathway to AtMC1. In addition, we unveiled an additional, pro-survival homeostatic function of AtMC1 in aging plants that acts in parallel to a similar pro-survival function of autophagy. This novel pro-survival role of AtMC1 may be functionally related to its prodomain-mediated aggregate localization and potential clearance, in agreement with recent findings using the single budding yeast metacaspase YCA1. We propose a unifying model whereby autophagy and AtMC1 are part of parallel pathways, both positively regulating HR cell death in young plants, when these functions are not masked by the cumulative stresses of aging, and negatively regulating senescence in older plants.
Asunto(s)
Apoptosis , Proteínas de Arabidopsis/metabolismo , Arabidopsis/enzimología , Autofagia , Caspasas/metabolismo , Senescencia Celular , Arabidopsis/citología , Arabidopsis/metabolismoRESUMEN
Los glucosaminoglicanos (GAG) son componentes fundamentales de las membranas basales de distintos órganos, entre ellos el riñón y la retina. Objetivos. Relacionar su excreción urinaria, fiel reflejo de la alteración de la función renal, con un dato observable como es la lesión de los vasos retinianos. Material y métodos. Se estudian 96 sujetos sanos tomados como control y 204 pacientes diagnosticados de hipertensión arterial esencial y distribuidos según el grado de retinopatía. Los GAG se determinaron en orina de 24 horas según un método colorimétrico. Resultados. La excreción urinaria de GAG aumenta en relación al grado de retinopatía hipertensiva. Sin embargo la correlación de otros parámetros bioquímicos de lesión renal (ácido úrico sérico, aclaramiento de creatinina, microalbuminuria con la afectación renal en el paciente hipertenso, no es tan manifiesta. Conclusiones. Los GAG eliminados por la orina, utilizados como marcador de nefropatía, se relacionan con las lesiones retinianas en el hipertenso
Glycosaminoglycans (GAGs) are the main components of basement membranes in different organs such as the kidney and the retina. Objective: To link urinary excretion that accurately shows renal function changes with retinal injury. Material and methods. Ninety-six healthy subjects were used as controls and 204 patients with essential arterial hypertension were divided according to the retinopathy stage. GAGs were determined in 24 hour urine samples following a colorimetric method. Results. GAGs in urine increase depending on the stage of hypertensive retinopathy. However, the correlation of other biochemical parameters of renal injuries (such as serum uric acid, creatine clearance, microalbuminuria9 with the renal disease in the hypertensive patient is not so evident
Asunto(s)
Humanos , Enfermedades de la Retina/fisiopatología , Hipertensión Ocular/fisiopatología , Glicosaminoglicanos/orina , Estudios de Casos y Controles , Enfermedades Renales/fisiopatología , Biomarcadores/análisisRESUMEN
CASE REPORT: We present a case of congenital Horner's Syndrome in a four year-old boy. The patient was referred from the Dermatology ward after a check up for malformations present from birth on the left upper limb. A significant factor was determined: a varicella related infection in the mother during the 12th week of pregnancy. Blood tests confirmed a diagnosis of congenital varicella syndrome. DISCUSSION: Congenital Horner's Syndrome is a rare entity, caused mainly by traumatic deliveries. Very rarely it is produced by severe lesions, such as neuroblastoma or viral infections as varicella. In our case, condition was associated to ipsilateral malformations of the upper limb, which is typical from congenital varicella syndrome apparently due to radiculopathy produced by the virus.
Asunto(s)
Varicela , Síndrome de Horner/congénito , Síndrome de Horner/etiología , Complicaciones Infecciosas del Embarazo , Preescolar , Femenino , Humanos , Masculino , EmbarazoRESUMEN
Caso clínico: Se presenta el caso de un niño de 4 años de edad con el diagnóstico de síndrome de Horner congénito. Fue remitido por el servicio de Dermatología donde estaba siendo revisado por presentar malformaciones en miembro superior izquierdo desde el nacimiento. Destacaba el antecedente de varicela materna en la 12 semana de gestación. La serología de sangre confirmó el diagnóstico de síndrome de varicela congénita. Discusión: El síndrome de Horner congénito es una entidad muy poco frecuente cuya causa principal es la historia de parto traumático. Muy raramente se produce por lesiones graves, como el neuroblastoma, y por infecciones virales, como la varicela. En nuestro caso se asociaba a lesiones malformativas de miembro superior ipsilateral que son muy características del síndrome de varicela congénita, al parecer por una radiculopatía producida por el virus (AU)
Asunto(s)
Embarazo , Preescolar , Masculino , Femenino , Humanos , Complicaciones Infecciosas del Embarazo , Varicela , Síndrome de HornerRESUMEN
Objetivo: Estudiar la excreción urinaria del enzima N-acetil-beta-glucosaminidasa (NAG), marcador bioquímico de daño renal precoz, en diabéticos tipo 2 con diferentes grados de retinopatía, estableciendo su relación con el grado de afección retiniana. Método: Realizamos un estudio prospectivo de 144 pacientes diabéticos tipo 2 y 94 controles sanos. Se les realizó una exploración oftalmológica (incluida angiografía fluoresceínica) y un estudio bioquímico que incluía la determinación de NAG en orina. Los pacientes fueron clasificados en varios grupos, dependiendo de su afección retiniana: 76 no presentaban retinopatía diabética (40 hombres y 36 mujeres), 30 tenían retinopatía no proliferativa precoz (13 hombres y 17 mujeres), 22 retinopatía no proliferativa avanzada (5 hombres y 17 mujeres) y 21 pacientes presentaban retinopatía diabética proliferativa (10 hombres y 11 mujeres). Los resultados se sometieron a un análisis estadístico mediante comparación de medias con el test de la t de Student. Resultados: Nuestros resultados mostraron que existe un aumento en la excreción urinaria de NAG conforme avanza el grado de retinopatía diabética. Asimismo, también destacamos la mayor excreción urinaria de NAG en los pacientes diabéticos que no presentaban retinopatía respecto a los controles sanos. Conclusión: Existe un paralelismo entre las lesiones renales y retinianas en la diabetes tipo 2, tal y como otros autores habían demostrado previamente para la diabetes tipo 1 (AU)
Asunto(s)
Persona de Mediana Edad , Masculino , Femenino , Humanos , Estudios Prospectivos , Retinopatía Diabética , AcetilglucosaminidasaRESUMEN
PURPOSE: To test N-acetyl-beta-glucosaminidase (NAG) urinary excretion, early renal damage biochemical marker, in patients with non-insulin-dependent diabetes mellitus grouped according to the degree of retinopathy, establishing its relationships to retinal involvement. METHODS: We make a prospective study of 144 type 2 diabetic patients and 94 healthy subjects. We realized an ocular exploration that included fluorescein angiography and a biochemical study that included the determination of NAG urinary excretion in all of them. The patients were grouped depending on their retinal disease. 76 subjects without retinal abnormalities (40 men and 36 women), 30 with early nonproliferative diabetic retinopathy (13 men and 17 women) and 21 subjects with proliferative diabetic retinopathy (10 men and 11 women). Results were analyzed by using statistical analyses. RESULTS: Our results showed that there exist an increase in the urinary excretion of NAG according to the degree of diabetic retinopathy advance. We also highlight the biggest urinary excretion of NAG in the diabetic patients without retinal involvement regarding healthy subjects. CONCLUSION: There is a parallelism between renal and retinal complications in type 2 diabetes mellitus as other authors had demonstrated previously for the type 1 diabetes mellitus.