RESUMEN
In efforts aimed at the detoxification of contaminated areas, plants have many advantages over bacteria and fungi. We are attempting to enhance the environmental decontamination functions of plants by transferring relevant genes from microorganisms. When the gene for Mn-peroxidase (MnP) from Coriolus versicolor was expressed in transgenic tobacco plants, one line (designated fMnP21) expressed MnP activity at levels 54-fold higher than in control lines. When undamaged roots of transgenic plants were applied to liquid medium supplemented with 250 microM pentachlorophenol (PCP), the decrease in the level of PCP in fMnP21 (86% reduction) was about 2-fold higher than that in control lines (38% reduction). Expression of the gene for MnP in the transgenic plants had no obvious negative effects on their vegetative and sexual growth. Our system should contribute to the development of novel methods for the removal of hazardous chemicals from contaminated environments using transgenic plants.
Asunto(s)
Basidiomycota/enzimología , Nicotiana/genética , Peroxidasas/genética , Biodegradación Ambiental , Peróxido de Hidrógeno/metabolismo , Pentaclorofenol/análisis , Pentaclorofenol/metabolismo , Plantas Modificadas Genéticamente , Nicotiana/metabolismoRESUMEN
Cinnamic acid 4-hydroxylase (CA4H) is the second enzyme involved in phenylpropanoid biosynthesis and is a member of the cytochrome P-450 superfamily. Three CA4H homologous genes, cyp73A, cyp73b, and cyp73c, and a cDNA clone of cyp73a were isolated from a genomic library and a cDNA library of a hybrid aspen; Populus kitakamiensis, and were characterized. They might be interrupted by two introns each. cyp73a and cyp73b were very similar to each other not only in coding regions but also in non-coding regions. Southern blot analysis showed that four homologous genes for CA4H constructed a small gene family in the diploid genome of P. kitakamiensis. In the promoter regions, there were many common cis-element-like sequences in phenylpropanoid biosynthesis genes.
Asunto(s)
Sistema Enzimático del Citocromo P-450/genética , Oxigenasas de Función Mixta/genética , Árboles/genética , Secuencia de Aminoácidos , Secuencia de Bases , Southern Blotting , Clonación Molecular , Fragmentación del ADN , ADN Complementario/aislamiento & purificación , Fabaceae/enzimología , Genoma de Planta , Hibridación Genética , Datos de Secuencia Molecular , Plantas Medicinales , Homología de Secuencia de Aminoácido , Homología de Secuencia de Ácido Nucleico , Transcinamato 4-MonooxigenasaAsunto(s)
Adenilil Ciclasas/metabolismo , Epidermis/enzimología , Terapia PUVA , 3',5'-AMP Cíclico Fosfodiesterasas/metabolismo , Adenosina/farmacología , Animales , AMP Cíclico/metabolismo , Células Epidérmicas , Epidermis/efectos de los fármacos , Epinefrina/farmacología , Histamina/farmacología , Técnicas In Vitro , Queratinas/metabolismo , Metoxaleno/administración & dosificación , PorcinosRESUMEN
The effects of topical PUVA treatment on the epidermal cyclic AMP system were investigated. 8-methoxypsoralen (8-MOP), 0.3% in ethanol was applied to the backs of pigs which were then irradiated with UVA. A significant increase in the epidermal beta-adrenergic adenylate cyclase response was observed 24 h after low (1.1 J/cm2) and moderate (2.1 J/cm2) dose irradiation. There was no significant change in the adenosine- or histamine-mediated adenylate cyclase responses. 8-MOP application or UVA irradiation alone had no effect on the beta-adrenergic adenylate cyclase response. PUVA treatment with a higher irradiation dose (4.2 J/cm2) produced no increase in the beta-adrenergic response and adenosine- and histamine-mediated adenylate cyclase responses were decreased. Cyclic AMP phosphodiesterase activity was decreased by PUVA treatments using UVA doses of 1.1 and 2.1 J/cm2; however, the change was not statistically significant. The increased beta-adrenergic response was also observed in the presence of the cyclic AMP phosphodiesterase inhibitor, isobutylmethylxanthine. These results indicate that epidermal adenylate cyclase responsiveness is affected by topical PUVA treatment in vivo.