Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 66
Filtrar
1.
Int J Mol Sci ; 22(11)2021 May 31.
Artículo en Inglés | MEDLINE | ID: mdl-34073052

RESUMEN

Pigeonpea [Cajanus cajan (L.) Millspaugh] is an economically important legume playing a crucial role in the semi-arid tropics. Pigeonpea is susceptible to Helicoverpa armigera (Hübner), which causes devastating yield losses. This pest is developing resistance to many commercially available insecticides. Therefore, crop wild relatives of pigeonpea, are being considered as potential sources of genes to expand the genetic base of cultivated pigeonpea to improve traits such as host plant resistance to pests and pathogens. Quantitative proteomic analysis was conducted using the tandem mass tag platform to identify differentially abundant proteins between IBS 3471 and ICPL 87 tolerant accession and susceptible variety to H. armigera, respectively. Leaf proteome were analysed at the vegetative and flowering/podding growth stages. H. armigera tolerance in IBS 3471 appeared to be related to enhanced defence responses, such as changes in secondary metabolite precursors, antioxidants, and the phenylpropanoid pathway. The development of larvae fed on an artificial diet with IBS 3471 lyophilised leaves showed similar inhibition with those fed on an artificial diet with quercetin concentrations with 32 mg/25 g of artificial diet. DAB staining (3,3'-diaminobenzidine) revealed a rapid accumulation of reactive oxygen species in IBS 3471. We conclude that IBS 3471 is an ideal candidate for improving the genetic base of cultivated pigeonpea, including traits for host plant resistance.


Asunto(s)
Cajanus/metabolismo , Mariposas Nocturnas , Hojas de la Planta/metabolismo , Proteínas de Plantas/metabolismo , Animales , Larva , Proteoma
2.
J Econ Entomol ; 113(2): 974-979, 2020 04 06.
Artículo en Inglés | MEDLINE | ID: mdl-31967641

RESUMEN

Cowpea [Vigna unguiculata (L) Walp.] is an important staple legume in the diet of many households in sub-Saharan Africa. Its production, however, is negatively impacted by many insect pests including bean pod borer, Maruca vitrata F., which can cause 20-80% yield loss. Several genetically engineered cowpea events that contain a cry1Ab gene from Bacillus thuringiensis (Bt) for resistance against M. vitrata were evaluated in Nigeria, Burkina Faso, and Ghana (West Africa), where cowpea is commonly grown. As part of the regulatory safety package, these efficacy data were developed and evaluated by in-country scientists. The Bt-cowpea lines were planted in confined field trials under Insect-proof netting and artificially infested with up to 500 M. vitrata larvae per plant during bud formation and flowering periods. Bt-cowpea lines provided nearly complete pod and seed protection and in most cases resulted in significantly increased seed yield over non-Bt control lines. An integrated pest management strategy that includes use of Bt-cowpea augmented with minimal insecticide treatment for protection against other insects is recommended to control pod borer to enhance cowpea production. The insect resistance management plan is based on the high-dose refuge strategy where non-Bt-cowpea and natural refuges are expected to provide M. vitrata susceptible to Cry1Ab protein. In addition, there will be a limited release of this product until a two-toxin cowpea pyramid is released. Other than South African genetically engineered crops, Bt-cowpea is the first genetically engineered food crop developed by the public sector and approved for release in sub-Saharan Africa.


Asunto(s)
Fabaceae , Lepidópteros , Mariposas Nocturnas/genética , Vigna , Animales , Proteínas Bacterianas , Burkina Faso , Endotoxinas , Larva , Nigeria , Control Biológico de Vectores , Plantas Modificadas Genéticamente
3.
Front Plant Sci ; 10: 219, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-30873198

RESUMEN

An improved cowpea transformation method utilizing Agrobacterium-mediated gene delivery to explants derived from the cotyledonary nodes of imbibed cowpea seed is described. The explants were regenerated following a sonication procedure and a stringent selection comprising alternating regimes of kanamycin and geneticin. The method was reproducible and led to the recovery of independent fertile transgenic plants in the greenhouse at a level of about one per cent of starting explants. A transgene encoding an insecticidal protein from Bacillus thuringiensis was used to demonstrate the efficacy of the system.

4.
Abdom Radiol (NY) ; 43(10): 2686-2692, 2018 10.
Artículo en Inglés | MEDLINE | ID: mdl-29500648

RESUMEN

OBJECTIVE: The purpose of this study was to compare the sensitivity and specificity of diffusion-weighted liver MRI alone with complete, multiphasic gadoteridol-enhanced MRI for the detection of hepatocellular carcinoma in cirrhotic patients before liver transplant. MATERIALS AND METHODS: This single institution retrospective study was performed after IRB approval and was HIPAA compliant. MRI scans of 37 patients who underwent liver transplant were evaluated and findings correlated with liver explant (36) or biopsy (1). All MRI scans were obtained within six months of explant. MRI from 17 patients with liver lesions by report at imaging subsequently proven to be HCC at pathology and 20 controls without liver lesions by imaging and pathology were reviewed in random order on the radiology PACS by three independent readers blinded to the MRI reports and pathology reports in two separate sittings. First, only the diffusion-weighted images (DWI) were interpreted. Second, the complete multiphasic MRI exam with DWI was reviewed. A consensus read was obtained by two separate radiologists who had access to the patients' explant data in order to map lesions. Reader-specific and pooled classification was assessed using sensitivity, specificity, positive predictive value, and negative predictive values and corresponding 95% confidence intervals (CI) for both DWI and complete MRI examination readings compared to pathology. McNemar's test and Kappa coefficient were used to assess differences (agreement) in DWI and complete examination readings. RESULTS: A total of 37 patients have been studied (25M 12F age range 21-70). Averaged results of the three independent readers demonstrated a sensitivity of 78% (95% CI 65-89%) and specificity of 88% (95% CI 77-95%) for DWI alone for detection of liver lesions, with a positive predictive value of 85% (95% CI 72-94%) and a negative predictive value of 83% (95% CI 71-91%). Review of the complete MRI exam showed a sensitivity of 90% (95% CI 76-97%) and a specificity of 82% (95% CI 66-92%) with a positive predictive value of 83% (95% CI 69-93%) and a negative predictive value of 89% (95% CI 74-97%). McNemar's agreement test revealed no significant difference between the DWI and complete multiphasic interpretations (p = 0.3458), with simple Kappa coefficient of 0.6716 (95% CI 0.5332-0.8110). Lesions identified on DWI ranged in size from 1.5 to 5 cm. Detection of lesions was decreased in the presence of artifact from motion, large ascites, and technical issues. CONCLUSION: Diffusion-weighted MRI has NPV and PPV comparable to complete multiphasic MRI examination for liver lesion detection in cirrhotic patients and may have a role in screening.


Asunto(s)
Carcinoma Hepatocelular/diagnóstico por imagen , Imagen de Difusión por Resonancia Magnética/métodos , Cirrosis Hepática/diagnóstico por imagen , Neoplasias Hepáticas/diagnóstico por imagen , Trasplante de Hígado , Adulto , Anciano , Carcinoma Hepatocelular/patología , Carcinoma Hepatocelular/cirugía , Medios de Contraste , Femenino , Humanos , Cirrosis Hepática/patología , Cirrosis Hepática/cirugía , Neoplasias Hepáticas/patología , Neoplasias Hepáticas/cirugía , Masculino , Persona de Mediana Edad , Proyectos Piloto , Complicaciones Posoperatorias/diagnóstico por imagen , Complicaciones Posoperatorias/patología , Valor Predictivo de las Pruebas , Sensibilidad y Especificidad
5.
J Food Prot ; 78(2): 436-45, 2015 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-25710164

RESUMEN

The majority of human listeriosis cases appear to be caused by consumption of ready-to-eat (RTE) foods contaminated at the time of consumption with high levels of Listeria monocytogenes. Although strategies to prevent growth of L. monocytogenes in RTE products are critical for reducing the incidence of human listeriosis, control of postprocessing environmental contamination of RTE meat and poultry products is an essential component of a comprehensive L. monocytogenes intervention and control program. Complete elimination of postprocessing L. monocytogenes contamination is challenging because this pathogen is common in various environments outside processing plants and can persist in food processing environments for years. Persistent L. monocytogenes strains in processing plants have been identified as the most common postprocessing contaminants of RTE foods and the cause of multiple listeriosis outbreaks. Identification and elimination of L. monocytogenes strains persisting in processing plants is thus critical for (i) compliance with zero-tolerance regulations for L. monocytogenes in U.S. RTE meat and poultry products and (ii) reduction of the incidence of human listeriosis. The seek-and-destroy process is a systematic approach to finding sites of persistent strains (niches) in food processing plants, with the goal of either eradicating or mitigating effects of these strains. This process has been used effectively to address persistent L. monocytogenes contamination in food processing plants, as supported by peer-reviewed evidence detailed here. Thus, a regulatory environment that encourages aggressive environmental Listeria testing is required to facilitate continued use of this science-based strategy for controlling L. monocytogenes in RTE foods.


Asunto(s)
Comida Rápida/microbiología , Contaminación de Alimentos/análisis , Manipulación de Alimentos/métodos , Listeria monocytogenes/crecimiento & desarrollo , Listeriosis/microbiología , Animales , Contaminación de Alimentos/prevención & control , Manipulación de Alimentos/normas , Humanos , Estados Unidos
6.
J Food Prot ; 76(5): 796-811, 2013 May.
Artículo en Inglés | MEDLINE | ID: mdl-23643121

RESUMEN

Listeria monocytogenes persistence in food processing plants is a key source of postprocessing contamination of ready-to-eat foods. Thus, identification and elimination of sites where L. monocytogenes persists (niches) is critical. Two smoked fish processing plants were used as models to develop and implement environmental sampling plans (i) to identify persistent L. monocytogenes subtypes (EcoRI ribotypes) using two statistical approaches and (ii) to identify and eliminate likely L. monocytogenes niches. The first statistic, a binomial test based on ribotype frequencies, was used to evaluate L. monocytogenes ribotype recurrences relative to reference distributions extracted from a public database; the second statistic, a binomial test based on previous positives, was used to measure ribotype occurrences as a risk factor for subsequent isolation of the same ribotype. Both statistics revealed persistent ribotypes in both plants based on data from the initial 4 months of sampling. The statistic based on ribotype frequencies revealed persistence of particular ribotypes at specific sampling sites. Two adaptive sampling strategies guided plant interventions during the study: sampling multiple times before and during processing and vector swabbing (i.e., sampling of additional sites in different directions [vectors] relative to a given site). Among sites sampled for 12 months, a Poisson model regression revealed borderline significant monthly decreases in L. monocytogenes isolates at both plants (P = 0.026 and 0.076). Our data indicate elimination of an L. monocytogenes niche on a food contact surface; niches on nonfood contact surfaces were not eliminated. Although our data illustrate the challenge of identifying and eliminating L. monocytogenes niches, particularly at nonfood contact sites in small and medium plants, the methods for identification of persistence we describe here should broadly facilitate science-based identification of microbial persistence.


Asunto(s)
Productos Pesqueros/microbiología , Contaminación de Alimentos/análisis , Industria de Procesamiento de Alimentos/normas , Listeria monocytogenes/aislamiento & purificación , Modelos Estadísticos , Animales , Seguridad de Productos para el Consumidor , Microbiología Ambiental , Contaminación de Alimentos/estadística & datos numéricos , Industria de Procesamiento de Alimentos/estadística & datos numéricos , Humanos , Listeria monocytogenes/genética , Ribotipificación
7.
Bull Entomol Res ; 103(4): 373-81, 2013 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-23458831

RESUMEN

Dry grain legume seeds possessing αAI-1, an α-amylase inhibitor from common bean (Phaseolus vulgaris), under the control of a cotyledon-specific promoter have been shown to be highly resistant to several important bruchid pest species. One transgenic chickpea and four cowpea lines expressing αAI-1, their respective controls, as well as nine conventional chickpea cultivars were assessed for their resistance to the bruchids Acanthoscelides obtectus (Say), Callosobruchus chinensis L. and Callosobruchus maculatus F. All transgenic lines were highly resistant to both Callosobruchus species. A. obtectus, known to be tolerant to αAI-1, was able to develop in all transgenic lines. While the cotyledons of all non-transgenic cultivars were highly susceptible to all bruchids, C. chinensis and C. maculatus larvae suffered from significantly increased mortality rates inside transgenic seeds. The main factor responsible for the partial resistance in the non-transgenic cultivars was deduced to reside in the seed coat. The αAI-1 present in seeds of transgenic chickpea and cowpea lines significantly increases their resistance to two important bruchid pest species (C. chinensis and C. maculatus) essentially to immunity. To control αAI-1 tolerant bruchid species such as A. obtectus and to avoid the development of resistance to αAI-1, varieties carrying this transgene should be protected with additional control measures.


Asunto(s)
Cicer/inmunología , Escarabajos/patogenicidad , Fabaceae/inmunología , Inmunidad Innata/inmunología , Enfermedades de las Plantas/parasitología , Plantas Modificadas Genéticamente/inmunología , Semillas/inmunología , Animales , Cicer/genética , Fabaceae/genética , Genotipo , Enfermedades de las Plantas/inmunología , Plantas Modificadas Genéticamente/genética , Semillas/metabolismo , alfa-Amilasas/antagonistas & inhibidores
8.
Clin Radiol ; 68(2): 148-54, 2013 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-22889459

RESUMEN

AIM: To evaluate lesion contrast in pancreatic adenocarcinoma patients using spectral multidetector computed tomography (MDCT) analysis. MATERIALS AND METHODS: The present institutional review board-approved, Health Insurance Portability and Accountability Act of 1996 (HIPAA)-compliant retrospective study evaluated 64 consecutive adults with pancreatic adenocarcinoma examined using a standardized, multiphasic protocol on a single-source, dual-energy MDCT system. Pancreatic phase images (35 s) were acquired in dual-energy mode; unenhanced and portal venous phases used standard MDCT. Lesion contrast was evaluated on an independent workstation using dual-energy analysis software, comparing tumour to non-tumoural pancreas attenuation (HU) differences and tumour diameter at three energy levels: 70 keV; individual subject-optimized viewing energy level (based on the maximum contrast-to-noise ratio, CNR); and 45 keV. The image noise was measured for the same three energies. Differences in lesion contrast, diameter, and noise between the different energy levels were analysed using analysis of variance (ANOVA). Quantitative differences in contrast gain between 70 keV and CNR-optimized viewing energies, and between CNR-optimized and 45 keV were compared using the paired t-test. RESULTS: Thirty-four women and 30 men (mean age 68 years) had a mean tumour diameter of 3.6 cm. The median optimized energy level was 50 keV (range 40-77). The mean ± SD lesion contrast values (non-tumoural pancreas - tumour attenuation) were: 57 ± 29, 115 ± 70, and 146 ± 74 HU (p = 0.0005); the lengths of the tumours were: 3.6, 3.3, and 3.1 cm, respectively (p = 0.026); and the contrast to noise ratios were: 24 ± 7, 39 ± 12, and 59 ± 17 (p = 0.0005) for 70 keV, the optimized energy level, and 45 keV, respectively. For individuals, the mean ± SD contrast gain from 70 keV to the optimized energy level was 59 ± 45 HU; and the mean ± SD contrast gain from the optimized energy level to 45 keV was 31 ± 25 HU (p = 0.007). CONCLUSION: Significantly increased pancreatic lesion contrast was noted at lower viewing energies using spectral MDCT. Individual patient CNR-optimized energy level images have the potential to improve lesion conspicuity.


Asunto(s)
Adenocarcinoma/diagnóstico por imagen , Tomografía Computarizada Multidetector/métodos , Neoplasias Pancreáticas/diagnóstico por imagen , Intensificación de Imagen Radiográfica/métodos , Adenocarcinoma/patología , Adenocarcinoma/cirugía , Adulto , Anciano , Anciano de 80 o más Años , Biopsia con Aguja , Estudios de Cohortes , Femenino , Estudios de Seguimiento , Humanos , Inmunohistoquímica , Masculino , Persona de Mediana Edad , Invasividad Neoplásica/patología , Estadificación de Neoplasias , Pancreatectomía/métodos , Neoplasias Pancreáticas/patología , Neoplasias Pancreáticas/cirugía , Dosis de Radiación , Estudios Retrospectivos
9.
Proteomics ; 9(18): 4406-15, 2009 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-19725077

RESUMEN

Seeds of genetically modified (GM) peas (Pisum sativum L.) expressing the gene for alpha-amylase inhibitor-1 (alphaAI1) from the common bean (Phaseolus vulgaris L. cv. Tendergreen) exhibit resistance to the pea weevil (Bruchus pisorum). A proteomic analysis was carried out to compare seeds from GM pea lines expressing the bean alphaAI1 protein and the corresponding alphaAI1-free segregating lines and non-GM parental line to identify unintended alterations to the proteome of GM peas due to the introduction of the gene for alphaAI1. Proteomic analysis showed that in addition to the presence of alphaAI1, 33 other proteins were differentially accumulated in the alphaAI1-expressing GM lines compared with their non-GM parental line and these were grouped into five expression classes. Among these 33 proteins, only three were found to be associated with the expression of alphaAI1 in the GM pea lines. The accumulation of the remaining 30 proteins appears to be associated with Agrobacterium-mediated transformation events. Sixteen proteins were identified after MALDI-TOF-TOF analysis. About 56% of the identified proteins with altered accumulation in the GM pea were storage proteins including legumin, vicilin or convicilin, phaseolin, cupin and valosin-containing protein. Two proteins were uniquely expressed in the alphaAI1-expressing GM lines and one new protein was present in both the alphaAI1-expressing GM lines and their alphaAI1-free segregating lines, suggesting that both transgenesis and transformation events led to demonstrable changes in the proteomes of the GM lines tested.


Asunto(s)
Pisum sativum/metabolismo , Lectinas de Plantas/biosíntesis , Proteínas de Plantas/biosíntesis , Plantas Modificadas Genéticamente/metabolismo , Proteómica/métodos , Proteínas de Almacenamiento de Semillas/biosíntesis , Análisis de Varianza , Animales , Electroforesis en Gel Bidimensional , Ratones , Pisum sativum/genética , Péptidos/metabolismo , Lectinas de Plantas/genética , Lectinas de Plantas/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Modificadas Genéticamente/genética , Proteoma/metabolismo , Proteínas de Almacenamiento de Semillas/genética , Proteínas de Almacenamiento de Semillas/metabolismo , Semillas/genética , Semillas/metabolismo
10.
Electrophoresis ; 30(11): 1863-8, 2009 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-19517428

RESUMEN

Differential in-gel electrophoresis showed contrasting effects of the transgenic expression of an alpha-amylase inhibitor from beans on the proteomes of two pea cultivars. One cultivar showed minor changes relative to its non-transgenic parent with only one protein changing by more than about twofold. Changes in the abundance of certain endogenous proteins in the other cultivar were of greater number and magnitude with some endogenous proteins undetected while some new protein spots appeared in the transgenic proteome. The sets of proteins with altered expression were generally different between the two cultivars. Some of the proteins that were differentially expressed were identified by MS. Most were seed storage globulins, which are sited together with the transgenic product. Some of the changes may be due to alterations in expression levels but there were also changes due to post-translational processing.


Asunto(s)
Pisum sativum/metabolismo , Lectinas de Plantas/biosíntesis , Proteínas de Plantas/metabolismo , Plantas Modificadas Genéticamente/metabolismo , Proteoma/metabolismo , Electroforesis en Gel Bidimensional , Procesamiento de Imagen Asistido por Computador , Espectrometría de Masas , Pisum sativum/genética , Phaseolus/genética , Lectinas de Plantas/genética , Lectinas de Plantas/metabolismo , Proteínas de Plantas/biosíntesis , Proteínas de Plantas/genética , Plantas Modificadas Genéticamente/genética , Procesamiento Proteico-Postraduccional
11.
Plant J ; 60(1): 146-55, 2009 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-19508424

RESUMEN

The RNAs for the storage proteins of rice (Oryza sativa), prolamines and glutelins, which are stored as inclusions in the lumen of the endoplasmic reticulum (ER) and storage vacuoles, respectively, are targeted by specific cis-localization elements to distinct subdomains of the cortical ER. Glutelin RNA has one or more cis-localization elements (zip codes) at the 3' end of the RNA, whereas prolamine has two cis-elements; one located in the 5' end of the coding sequence and a second residing in the 3'-untranslated region (UTR). We had earlier demonstrated that the RNAs for the maize zeins ('prolamine' class) are localized to the spherical protein body ER (PB-ER) in developing maize endosperm. As the PB-ER localization of the 10-kDa delta-zein RNA is maintained in developing rice seeds, we determined the number and proximate location of their cis-localization elements by expressing GFP fusions containing various zein RNA sequences in transgenic rice and analyzing their spatial distribution on the cortical ER by in situ RT-PCR and confocal microscopy. Four putative cis-localization elements were identified; three in the coding sequences and one in the 3'-UTR. Two of these zip codes are required for restricted localization to the PB-ER. Using RNA targeting determinants we show, by mis-targeting the storage protein RNAs from their normal destination on the cortical ER, that the coded proteins are redirected from their normal site of deposition. Targeting of RNA to distinct cortical ER subdomains may be the underlying basis for the variable use of the ER lumen or storage vacuole as the final storage deposition site of storage proteins among flowering plant species.


Asunto(s)
Retículo Endoplásmico/metabolismo , Transporte de ARN , ARN de Planta/metabolismo , Zea mays/genética , Zeína/genética , Regiones no Traducidas 3' , Secuencia de Bases , Regulación de la Expresión Génica de las Plantas , Microscopía Confocal , Datos de Secuencia Molecular , Oryza/genética , Oryza/metabolismo , Plantas Modificadas Genéticamente/genética , Plantas Modificadas Genéticamente/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Alineación de Secuencia , Análisis de Secuencia de ARN , Zea mays/metabolismo , Zeína/metabolismo
12.
J Econ Entomol ; 100(4): 1416-22, 2007 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-17849896

RESUMEN

This glasshouse study used an improved larval measurement procedure to evaluate the impact of transgenic pea, Pisum sativum L., seeds expressing a-amylase inhibitor (AI)-1 or -2 proteins on pea weevil, Bruchus pisorum L. Seeds of transgenic 'Laura' and 'Greenfeast' peas expressing alpha-(AI)-1 reduced pea weevil survival by 93-98%. Larval mortality occurred at an early instar. Conversely, in nontransgenic cultivars, approximately 98-99% of the pea weevils emerged as adults. By measuring the head capsule size, we determined that larvae died at the first to early third instar in alpha-(AI)-1 transgenic peas, indicating that this inhibitor is highly effective in controlling this insect. By contrast, transgenic Laura and 'Dundale' expressing alpha-(AI)-2 did not affect pea weevil survival, but they did delay larval development. After 77 d of development, the head capsule size indicated that the larvae were still at the third instar stage in transgenic alpha-(AI)-2 peas, whereas adult bruchids had developed in the nontransgenic peas.


Asunto(s)
Control Biológico de Vectores , Phaseolus/genética , Pisum sativum/genética , Lectinas de Plantas/fisiología , Plantas Modificadas Genéticamente/enzimología , Gorgojos/crecimiento & desarrollo , Animales , Larva/crecimiento & desarrollo , Lectinas de Plantas/genética
13.
Plant Cell Rep ; 25(4): 304-12, 2006 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-16244884

RESUMEN

Cowpeas are nutritious grains that provide the main source of protein, highly digestible energy and vitamins to some of the world's poorest people. The demand for cowpeas is high but yields remain critically low, largely because of insect pests. Cowpea germplasm contains little or no resistance to major insect pests and a gene technology approach to adding insect protection traits is now a high priority. We have adapted features of several legume and other transformation systems and reproducibly obtained transgenic cowpeas that obey Mendelian rules in transmitting the transgene to their progeny. Critical parameters in this transformation system include the choice of cotyledonary nodes from developing or mature seeds as explants and a tissue culture medium devoid of auxins in the early stages, but including the cytokinin BAP at low levels during shoot initiation and elongation. Addition of thiol-compounds during infection and co-culture with Agrobacterium and the choice of the bar gene for selection with phosphinothricin were also important. Transgenic cowpeas that transmit the transgenes to their progeny can be recovered at a rate of one fertile plant per thousand explants. These results pave the way for the introduction of new traits into cowpea and the first genes to be trialled will include those with potential to protect against insect pests.


Asunto(s)
Fabaceae/genética , Fabaceae/fisiología , Regulación de la Expresión Génica de las Plantas , Transformación Genética , Medios de Cultivo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Modificadas Genéticamente , Reproducción/fisiología , Rhizobium , Selección Genética , Técnicas de Cultivo de Tejidos
14.
Phytochemistry ; 66(21): 2534-9, 2005 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-16242165

RESUMEN

Previous studies have shown differential accumulation of sulfur rich glutelins and sulfur poor prolamins in transgenic rice seeds expressing a sunflower seed albumin gene [Hagan, N.D., Upadhyaya, N., Tabe, L.M., Higgins, T.J., 2003. The redistribution of protein sulfur in transgenic rice expressing a gene for a foreign, sulfur-rich protein. Plant J 34, 1-11]. Here, we show, by two-dimensional electrophoresis, differential accumulation of three classes of glutelin proteins - type I, II and III - and a globulin, not previously resolved, in transgenic seeds grown under low and high sulfur nutrition. Several glutelin polypeptides were resolved and four identified as a type I glutelin, two type II glutelins and a type III glutelin. Although sulfur nutrition did not affect the accumulation of sunflower seed albumin, the levels of all four identified glutelins and the globulin were lower in mature seeds derived from transgenic plants grown under sulfur-optimum or sulfur limited conditions compared to non-transgenic rice seeds. The reduction of all four glutelin polypeptides and the globulin varied from 21% to 68%. The re-allocation of sulfur reserves from endogenous proteins to the sulfur sink in transgenic grain is suggestive of a transcriptional control of sulfur mobilization in plants.


Asunto(s)
Albúminas/genética , Glútenes/metabolismo , Helianthus/genética , Oryza/genética , Oryza/metabolismo , Semillas/genética , Albúminas/metabolismo , Regulación de la Expresión Génica de las Plantas/genética , Plantas Modificadas Genéticamente , Azufre
15.
J Exp Bot ; 55(396): 497-505, 2004 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-14718496

RESUMEN

The effects of water deficit and high temperature on the production of alpha-amylase inhibitor 1 (alpha-AI-1) were studied in transgenic peas (Pisum sativum L.) that were developed to control the seed-feeding pea weevil (Bruchus pisorum L., Coleoptera: Bruchidae). Transgenic and non-transgenic plants were subjected to water-deficit and high-temperature treatments under controlled conditions in the glasshouse and growth cabinet, beginning 1 week after the first pods were formed. In the water-deficit treatments, the peas were either adequately watered (control) or water was withheld after first pod formation. The high-temperature experiments were performed in two growth cabinets, one maintained at 27/22 degrees C (control) and one at 32/27 degrees C day/night temperatures, with the vapour pressure deficit maintained at 1.3 kPa. The plants exposure to high temperatures and water deficit produced 27% and 79% fewer seeds, respectively, than the controls. In the transgenic peas the level of alpha-AI-1 as a percentage of total protein was not influenced by water stress, but was reduced on average by 36.3% (the range in two experiments was 11-50%) in the high-temperature treatment. Transgenic and non-transgenic pods of plants grown at 27/22 degrees C and 32/27 degrees C were inoculated with pea weevil eggs to evaluate whether the reduction in level of alpha-AI-1 in the transgenic pea seeds affected pea weevil development and survival. At the higher temperatures, 39% of adult pea weevil emerged, compared to 1.2% in the transgenic peas grown at the lower temperatures, indicating that high temperature reduced the protective capacity of the transgenic peas.


Asunto(s)
Escarabajos/patogenicidad , Desecación , Inhibidores Enzimáticos/farmacología , Pisum sativum/fisiología , Semillas/enzimología , alfa-Amilasas/antagonistas & inhibidores , Aclimatación , Animales , Calor , Pisum sativum/efectos de los fármacos , Pisum sativum/parasitología , Enfermedades de las Plantas/parasitología , Plantas Modificadas Genéticamente/efectos de los fármacos , Plantas Modificadas Genéticamente/parasitología , Plantas Modificadas Genéticamente/fisiología
16.
Plant Biotechnol J ; 1(6): 479-90, 2003 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-17134405

RESUMEN

A transgenic line of subterranean clover (Trifolium subterraneum) containing a gene for a sulphur-rich sunflower seed albumin (ssa gene) and a gene conferring tolerance to the herbicide phosphinothricin (bar gene) was previously shown to stably express these genes as far as the T3 generation. In subsequent generations there was a progressive decline in the level of expression of both of these genes such that, by the T7 generation, the plants were almost completely susceptible to the herbicide and the mean level of sunflower seed albumin was reduced to 10-30% of the level in the T2 and T3 generations. The decline in SSA protein correlated closely with a decline in the level of ssa RNA. In vitro transcription experiments with nuclei isolated from plants of the early and late generations showed that the reduced mRNA level was associated with a reduced level of transcription of the ssa transgene. Transcription of the bar transgene was also reduced in the late generations. Bisulphite sequencing analysis showed that the decline in expression of the ssa gene between T3 and subsequent generations correlated closely with increased CpG methylation in the promoter, but not in the coding region. Analysis of the bar gene promoter showed that high levels of CpG methylation preceded the first detectable decline in expression of the bar gene by one generation, suggesting that methylation was not the direct cause of transgene silencing in these plants.

17.
Plant J ; 30(2): 165-75, 2002 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-12000453

RESUMEN

During the storage phase, cotyledons of developing pea seeds are nourished by nutrients released to the seed apoplasm by their maternal seed coats. Sucrose is transported into pea cotyledons by sucrose/H+ symport mediated by PsSUT1 and possibly other sucrose symporters. PsSUT1 is principally localised to plasma membranes of cotyledon epidermal and subepidermal transfer cells abutting the seed coat. We tested the hypothesis that endogenous sucrose/H+ symporter(s) regulate sucrose import into developing pea cotyledons. This was done by supplementing their transport activity with a potato sucrose symporter (StSUT1), selectively expressed in cotyledon storage parenchyma cells under control of a vicilin promoter. In segregating transgenic lines, enhanced [(14)C]sucrose influx into cotyledons above wild-type levels was found to be dependent on StSUT1 expression. The transgene significantly increased (approximately 2-fold) transport activity of cotyledon storage parenchyma tissues where it was selectively expressed. In contrast, sucrose influx into whole cotyledons through the endogenous epidermal transfer cell pathway was increased by only 23% in cotyledons expressing the transgene. A similar response was found for rates of biomass gain by intact cotyledons and by excised cotyledons cultured on a sucrose medium. These observations demonstrate that transport activities of sucrose symporters influence cotyledon growth rates. The attenuated effect of StSUT1 overexpression on sucrose and dry matter fluxes by whole cotyledons is consistent with a large proportion of sucrose being taken up at the cotyledonary surface. This indicates that the cellular location of sucrose transporter activity plays a key role in determining rates of sucrose import into cotyledons.


Asunto(s)
Cotiledón/crecimiento & desarrollo , Cotiledón/metabolismo , Proteínas de Transporte de Membrana/metabolismo , Pisum sativum/metabolismo , Proteínas de Plantas/metabolismo , Semillas/metabolismo , Solanum tuberosum/genética , Sacarosa/metabolismo , Transporte Biológico , Biomasa , Cotiledón/genética , Técnicas de Cultivo , Expresión Génica , Genes de Plantas/genética , Hibridación in Situ , Cinética , Proteínas de Transporte de Membrana/genética , Pisum sativum/genética , Pisum sativum/crecimiento & desarrollo , Proteínas de Plantas/genética , Plantas Modificadas Genéticamente , Regiones Promotoras Genéticas/genética , Semillas/genética , Semillas/crecimiento & desarrollo , Transgenes/genética
18.
Ophthalmic Surg Lasers ; 28(6): 452-60, 1997 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-9189948

RESUMEN

BACKGROUND AND OBJECTIVES: To assess the differences in history, clinical course, and response between five cases of blebitis and three cases of endophthalmitis following mitomycin trabeculectomy. PATIENTS AND METHODS: The authors conducted a retrospective review of eight consecutive cases of bleb-related infection following successful mitomycin trabeculectomy. RESULTS: All patients with blebitis responded to treatment with return of visual acuity and intraocular pressure to preinfection levels. In the three cases of endophthalmitis, one patient underwent enucleation, one had a final visual acuity of counting fingers, and the third had a visual acuity of 20/60. CONCLUSIONS: Blebitis, a limited form of bleb-related infection with thin, cystic, leaky blebs, responds to intensive topical antibiotic treatment, returning visual acuity and IOP to preinfection levels. Bleb-related endophthalmitis causes a more virulent form of bleb-related infection that involves thin- or thick-walled blebs, with or without leakage, and poor visual prognosis despite immediate intensive topical, systemic, and intravitreal antibiotic administration combined with core vitrectomy.


Asunto(s)
Endoftalmitis/microbiología , Infecciones Bacterianas del Ojo , Trabeculectomía/efectos adversos , Administración Tópica , Adulto , Anciano , Antibacterianos , Antibióticos Antineoplásicos/administración & dosificación , Bacterias/aislamiento & purificación , Quimioterapia Adyuvante/efectos adversos , Conjuntiva/microbiología , Quimioterapia Combinada/uso terapéutico , Endoftalmitis/patología , Endoftalmitis/terapia , Infecciones Bacterianas del Ojo/etiología , Infecciones Bacterianas del Ojo/patología , Infecciones Bacterianas del Ojo/terapia , Femenino , Estudios de Seguimiento , Glaucoma/cirugía , Humanos , Masculino , Persona de Mediana Edad , Mitomicinas/administración & dosificación , Soluciones Oftálmicas , Complicaciones Posoperatorias/etiología , Complicaciones Posoperatorias/patología , Complicaciones Posoperatorias/terapia , Reoperación , Estudios Retrospectivos , Vitrectomía , Cuerpo Vítreo/microbiología , Cuerpo Vítreo/cirugía
19.
J Ophthalmic Nurs Technol ; 16(6): 292-300, 1997.
Artículo en Inglés | MEDLINE | ID: mdl-9460418

RESUMEN

1. Researchers have recently introduced the term "blebitis" to describe a limited form of bleb-related infection (with infection and inflammation limited to the bleb and the peri-bleb area, with or without anterior chamber involvement) in contrast to the more classic form of endophthalmitis. 2. Bleb-related endophthalmitis is the virulent form of bleb-related infection in which patients present with rapidly worsening visual acuity, redness, and pain with diffuse conjunctival congestion, opalescent blebs (with or without epithelial defects) with intense fibrin and/or hypopyon in the anterior chamber, and florid vitritis. 3. Blebitis and bleb-related endophthalmitis are two distinct bleb-related infections, each with different presentations, prognoses, and outcomes. It is important that clinicians recognize this and treat patients accordingly.


Asunto(s)
Endoftalmitis/diagnóstico , Endoftalmitis/microbiología , Infecciones Bacterianas del Ojo/diagnóstico , Infecciones Bacterianas del Ojo/microbiología , Complicaciones Posoperatorias/diagnóstico , Complicaciones Posoperatorias/microbiología , Adulto , Anciano , Diagnóstico Diferencial , Endoftalmitis/terapia , Infecciones Bacterianas del Ojo/terapia , Femenino , Humanos , Masculino , Persona de Mediana Edad , Complicaciones Posoperatorias/terapia , Trabeculectomía , Resultado del Tratamiento
20.
Indian J Exp Biol ; 33(7): 521-3, 1995 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-7590961

RESUMEN

Synthetic analogues of a monoterpenic fragment of aplasmomycin were tested for their antimalarial activity in Plasmodium falciparum culture in vitro. The antimalarial activities of these agents were evaluated in chloroquine sensitive strains. Parasite growth was inhibited in a dose dependent manner in the presence of the synthetic compounds (3-9).


Asunto(s)
Antibacterianos/farmacología , Antimaláricos/farmacología , Péptidos , Plasmodium falciparum/efectos de los fármacos , Terpenos/farmacología , Animales , Antibacterianos/química , Espectroscopía de Resonancia Magnética , Espectrometría de Masas , Espectrofotometría Infrarroja , Terpenos/química
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...