RESUMEN
Cinnamoyl-CoA reductase (CCR; EC 1.2.1.44) catalyses the conversion of cinnamoyl-CoAs into their corresponding cinnamaldehydes, i.e. the first step of the phenylpropanoid pathway specifically dedicated to the monolignol biosynthetic branch. In previous work, we described the isolation and characterisation of the first cDNA encoding CCR in Eucalyptus (Lacombe, E., Hawkins, S., Van Dorsselaere, J., Piquemal, J., Goffner, D., Poeydomenge, O., Boudet, A.M., Grima-Pettenati, J., 1997. Cinnamoyl CoA reductase, the first committed enzyme of the lignin branch biosynthetic pathway: cloning, expression and phylogenetic relationships. Plant Journal 11, 429--441) and shown the role of this enzyme in controlling the carbon flux into lignins (Piquemal, J., Lapierre, C., Myton, K., O'Connell, A., Schuch, W., Grima-Pettenati, J., Boudet, A.M., 1998. Down-regulation of cinnamoyl-CoA reductase induces significant changes of lignin profiles in transgenic tobacco plants. Plant Journal 13, 71--83). Here, we report the characterisation of two functionally and structurally distinct cDNA clones, AtCCR1 and AtCCR2 (81.6% protein sequence identity) in Arabidopsis thaliana. The two recombinant proteins expressed in Escherichia coli are able to use the three cinnamoyl-CoAs tested but with different levels of efficiency. AtCCR1 is five times more efficient with feruloyl-CoA and sinapoyl-CoA than AtCCR2. In addition, the two genes are differentially expressed during development and in response to infection. AtCCR1 is preferentially expressed in tissues undergoing lignification. In contrast, AtCCR2, which is poorly expressed during development, is strongly and transiently induced during the incompatible interaction with Xanthomonas campestris pv. campestris leading to a hypersensitive response. Altogether, these data suggest that AtCCR1 is involved in constitutive lignification whereas AtCCR2 is involved in the biosynthesis of phenolics whose accumulation may lead to resistance.
Asunto(s)
Aldehído Oxidorreductasas/genética , Arabidopsis/genética , Arabidopsis/microbiología , Regulación del Desarrollo de la Expresión Génica , Regulación de la Expresión Génica de las Plantas , Genes de Plantas , Xanthomonas campestris/patogenicidad , Aldehído Oxidorreductasas/química , Secuencia de Aminoácidos , Arabidopsis/enzimología , Clonación Molecular , ADN Complementario , Escherichia coli/genética , Datos de Secuencia Molecular , Homología de Secuencia de AminoácidoAsunto(s)
Actitud del Personal de Salud , Trastornos Mentales/etnología , Trastornos Mentales/enfermería , Relaciones Enfermero-Paciente , Personal de Enfermería en Hospital/psicología , Personal de Hospital/psicología , Etnología , Francia , Ambiente de Instituciones de Salud , Hospitales Psiquiátricos , Humanos , Rol de la Enfermera , Investigación Metodológica en Enfermería , Encuestas y CuestionariosRESUMEN
ACC (1-aminocyclopropane-1-carboxylate) oxidase genes are differentially expressed in melon during development and in response to various stresses. We investigated the molecular basis of their transcription by analyzing the 5' untranslated regions of the ACC oxidase genes CM-ACO1 and CM-ACO3. In order to determine how their temporal and spatial expression patterns were established, we fused the promoter regions of CM-ACO1 (726 bp) and CM-ACO3 (2260 bp) to the beta-glucuronidase (GUS) reporter gene and examined their regulation in transgenic tobacco plants. The CM-ACO1 promoter was able to drive GUS expression in response to wounding, and to treatment with ethylene or copper sulfate. It was also rapidly induced (8-12 h postinoculation) in tobacco leaves inoculated with the hypersensitive response (HR)-inducing bacterium Ralstonia solanacearum. Expression was also observed during compatible interactions but was delayed. In contrast, the CM-ACO3 promoter was not expressed in response to infection, but was up-regulated during flower development. Both promoters were regulated during leaf senescence but in different patterns. The CM-ACO1-driven GUS activity increased sharply concomitantly with the onset of chlorophyll breakdown, while the CM-ACO3 promoter drove strong GUS expression in green, fully expanded leaves and this declined at the onset of senescence. This result is consistent with the expression patterns of these two genes in senescent melon leaves. These data suggest that the regulation of expression of CM-ACO1 is related preferentially to stress responses, whereas CM-ACO3 seems to be associated with developmental processes. The possible role of ethylene is discussed, particularly in the regulation of the CM-ACO1 gene in response to stress and during senescence.
Asunto(s)
Aminoácido Oxidorreductasas/genética , Cucurbitaceae/enzimología , Cucurbitaceae/genética , Regulación de la Expresión Génica de las Plantas , Genes de Plantas , Secuencia de Bases , Cucurbitaceae/crecimiento & desarrollo , Cucurbitaceae/microbiología , Etilenos/farmacología , Regulación de la Expresión Génica de las Plantas/efectos de los fármacos , Bacilos y Cocos Aerobios Gramnegativos , Datos de Secuencia Molecular , Reguladores del Crecimiento de las Plantas/farmacología , Plantas Modificadas Genéticamente , Plantas Tóxicas , Regiones Promotoras Genéticas , Nicotiana/genéticaRESUMEN
The enzyme ACC oxidase catalyses the last step of ethylene biosynthesis in plants. Expression of the melon ACC oxidase gene, CM-ACO1, is rapidly induced (within 10 min) by ethylene treatment or upon wounding in leaves. The inhibitor of ethylene action, 1-methylcyclopropene (1-MCP), inhibited the accumulation of ethylene-induced CM-ACO1 mRNA transcripts, while wound-induced expression of the gene was not affected. The 5'-untranslated region of the CM-ACO1 gene was fused to the beta-glucuronidase (GUS) reporter gene and the corresponding transgenic tobacco plants were analysed. Two separate regions of the CM-ACO1 promoter activated GUS expression in response to ethylene treatment and wounding. These results suggest that induction of CM-ACO1 gene expression occurs via two separate signal transduction pathways in response to wounding and ethylene treatment.
Asunto(s)
Aminoácido Oxidorreductasas/genética , Aminoácidos Cíclicos , Aminoácidos/genética , Cucurbitaceae/genética , Etilenos/farmacología , Transducción de Señal/genética , Aminoácido Oxidorreductasas/biosíntesis , Aminoácidos/biosíntesis , Cucurbitaceae/enzimología , Inducción Enzimática/efectos de los fármacos , Regulación Enzimológica de la Expresión Génica/efectos de los fármacos , Regulación de la Expresión Génica de las Plantas/efectos de los fármacos , Genes de Plantas , Hojas de la Planta/enzimología , Hojas de la Planta/genética , Transducción de Señal/efectos de los fármacosRESUMEN
The enzyme ACC oxidase catalyses the last step of ethylene biosynthesis in plants, converting 1-aminocyclopropane-1-carboxylic acid (ACC) to ethylene. We have previously described the isolation and characterization of a cDNA clone (pMEL1) encoding an ACC oxidase homolog from melon (Cucumis melo L.). Here we report the isolation and characterization of three genomic clones, corresponding to three putative members of the ACC oxidase gene family in melon. All are transcriptionally active. The sequences of these genes have been determined. One genomic clone (CM-ACO1), corresponding to the cDNA previously isolated, presents a coding region interrupted by three introns. Its transcription initiation site has been defined with RNA from ripe fruit and ethylene-treated leaves. The other two genes (CM-ACO2, CM-ACO3) have only two introns, at positions identical to their counterparts in CM-ACO1. The degree of DNA homology in the coding regions of CM-ACO2 and CM-ACO3 relative to CM-ACO1 is 59% and 75%, respectively. CM-ACO2 and CM-ACO3 are 59% homologous in their coding regions. These three genes have close homology to PH-ACO3, a member of the ACC oxidase multigene family of petunia. The predicted amino acid sequences of CM-ACO1 and CM-ACO3 are 77% to 81% identical to those encoded by the tomato and petunia genes, while the deduced amino acid sequence of CM-ACO2 shows only 42% to 45% homology. RT-PCR analysis using gene-specific primers shows that the three genes are differentially expressed during development, ethylene treatment and wounding. CM-ACO1 is induced in ripe fruit and in response to wounding and to ethylene treatment in leaves. CM-ACO2 is detectable at low level in etiolated hypocotyls. CM-ACO3 is expressed in flowers and is not induced by any of the stimuli tested.
Asunto(s)
Aminoácido Oxidorreductasas/biosíntesis , Frutas/enzimología , Frutas/genética , Genes de Plantas , Filogenia , Empalme Alternativo , Aminoácido Oxidorreductasas/genética , Aminoácido Oxidorreductasas/metabolismo , Secuencia de Aminoácidos , Secuencia de Bases , Cartilla de ADN , ADN Complementario , Expresión Génica , Biblioteca Genómica , Solanum lycopersicum/enzimología , Solanum lycopersicum/genética , Datos de Secuencia Molecular , Plantas/enzimología , Plantas/genética , Reacción en Cadena de la Polimerasa , ARN de Planta/metabolismo , Mapeo Restrictivo , Homología de Secuencia de Aminoácido , Transcripción GenéticaRESUMEN
In keeping with the basic principles of Camey's procedure and with a view to improve continence, we decided in 1987 to experiment with the technique of ileal low-pressure bladder replacement (Camey II). We introduced the stapling technique in order to save time and to obtain watertight, reliable sutures. 57 patients underwent a Camey II intervention following radical cystectomy. Follow-up was 3-24 months. No operation mortality was observed and only 5 perioperative complications were recorded. Continence during the day and at night increased rapidly with Camey II (50% at 3 months, 90% at 6 months). Camey II improves the patients' quality of life; the procedure is simple, fast and reliable thanks to the stapling technique.
Asunto(s)
Cistectomía/rehabilitación , Íleon/trasplante , Engrapadoras Quirúrgicas , Adulto , Anciano , Anastomosis Quirúrgica , Humanos , Masculino , Persona de Mediana Edad , Complicaciones Posoperatorias , Presión , Uréter/cirugía , Uretra/cirugía , Neoplasias de la Vejiga Urinaria/cirugía , Micción/fisiologíaRESUMEN
Fourteen women within their menopausal period and suffering from stress urinary incontinence were studied. Electromyographic studies show that sphincter weakness is almost constant (9/14), usually associated with a bladder instability and/or a lack in abdominal urethral transmission, both conditions being known as possible causes of urinary stress incontinence. However, neurological causes at the origin of urinary stress incontinence, such as neurogenous sphincter, may be found (3/14). Electromyography, coupled with urodynamic evaluation, therefore presents itself as the most accurate method for a good assessment of correct pathophysiology in urinary stress incontinence and thereby for good therapeutic prescription.