RESUMEN
This paper describes our trial experience of the use of high radiation area for radiation education. We used environmental samples collected from the high radiation area in Fukushima prefecture and India, for the practice of radiation measurement and health risk assessment in Nagasaki University Medical School. We also carried out the field monitoring seminar for students in the existing exposure areas in Tottori prefecture and the Yamakiya observatory in Fukushima. Although the evaluation of educational effectiveness is still underway, both types of education appeared attractive for the students mostly due to the exposure from natural environment in our real life which was not achieved by using an artificial radiation source in a classroom.
Asunto(s)
Radiación de Fondo , Accidente Nuclear de Fukushima , Monitoreo de Radiación/métodos , Radiobiología/educación , Medición de Riesgo/métodos , Contaminantes Radiactivos del Suelo/análisis , Monitoreo del Ambiente , Humanos , India , Japón , Plantas de Energía NuclearRESUMEN
Most photosystem I and II plastid genes are transcribed by a plastid encoded Escherichia coli-like RNA polymerase (PEP). In this study, we show that both promoter selectivity and light-dependency of PEP change dramatically during development in wheat leaves. In the leaf tip, psbA and psbD promoter activities are light induced, whilst psbC, psbE and 16S rRNA promoters do not function efficiently irrespective of light conditions. In contrast to the leaf tip, in the basal portion all PEP promoters studied function in the dark as well as the light, except for psbD. Using in vitro transcription, we found that PEP in the illuminated leaf tip can initiate transcription from the -35 destructed psbA promoter, but the -35 element is essential for transcription in the basal portion. There is an extended -10 element in the psbA promoter, recognized by the PEP in the illuminated leaf tip or purified sigma 70-type Escherichia coli RNA polymerase but not by the PEP in the leaf base. These results suggest that during wheat leaf development, PEP in the leaf base that is functional for most PEP promoters even in the dark is replaced by the light-dependent PEP selectively transcribing the psbA and psbD promoters.
Asunto(s)
ARN Polimerasas Dirigidas por ADN/metabolismo , Triticum/enzimología , Secuencia de Bases , ADN de Plantas , ARN Polimerasas Dirigidas por ADN/genética , Luz , Datos de Secuencia Molecular , Proteínas del Complejo del Centro de Reacción Fotosintética/genética , Complejo de Proteína del Fotosistema I , Hojas de la Planta/enzimología , Hojas de la Planta/crecimiento & desarrollo , Regiones Promotoras Genéticas , Transcripción Genética/efectos de la radiación , Triticum/crecimiento & desarrolloRESUMEN
The activity of a light-responsive psbD promoter in plastids is known to be regulated by a circadian clock. However, the mechanism of the circadian regulation of the psbD light-responsive promotor, which is recognized by an Escherichia coli-type RNA polymerase, is not yet known. We examined the time course of mRNA accumulation of two E. coli-type RNA polymerase subunit genes, sigA and rpoA, under a continuous light condition after 12 h light/12 h dark entrainment. Accumulation of the sigA mRNA was found to be regulated by a circadian clock, while rpoA mRNA did not show any significant oscillation throughout the experiment.