RESUMEN
AtNUDT5 is a cytosol Nudix that catalyzes the hydrolysis of a variety of substrates. In this report, a 1,387-bp 5'-flanking region of the AtNUDT5 gene was isolated from Arabidopsis thaliana. The tissue-specific activity of the 5'-flanking region was investigated by using the GUS gene as a reporter in transgenic A. thaliana plants. Weak GUS activity appeared in vascular tissues of young plants, strong GUS activity appeared in the axial roots, but no GUS activity was observed in the root cap, lateral roots, rosette leaf, mature silique and reproductive tissues such as stamen, pistil, and petal. Furthermore, by using these transgenic A. thaliana plants, results of the histochemical staining and fluorometric assays of GUS activity showed that the AtNUDT5 promoter can be activated by both avirulent Pst avrRpm1 and virulent Pst strains at 5 h post-infiltration and that the activity of AtNUDT5 promoter increased significantly at 24 h post-infiltration. Taken together, our results demonstrated that the AtNUDT5 promoter is pathogen-responsive. The promoter may be used to develop transgenic plants with an increased tolerance to pathogenic stresses.
Asunto(s)
Proteínas de Arabidopsis/genética , Arabidopsis/genética , Proteínas Bacterianas/genética , Regulación de la Expresión Génica de las Plantas , Raíces de Plantas/genética , Pseudomonas syringae/genética , Pirofosfatasas/genética , Región de Flanqueo 5' , Arabidopsis/metabolismo , Arabidopsis/microbiología , Proteínas de Arabidopsis/metabolismo , Proteínas Bacterianas/metabolismo , Secuencia de Bases , Flores/genética , Flores/metabolismo , Flores/microbiología , Interacciones Huésped-Patógeno , Datos de Secuencia Molecular , Hojas de la Planta/genética , Hojas de la Planta/metabolismo , Hojas de la Planta/microbiología , Raíces de Plantas/metabolismo , Raíces de Plantas/microbiología , Tallos de la Planta/genética , Tallos de la Planta/metabolismo , Tallos de la Planta/microbiología , Plantas Modificadas Genéticamente , Regiones Promotoras Genéticas , Pseudomonas syringae/metabolismo , Pirofosfatasas/metabolismo , Hidrolasas NudixRESUMEN
Tapping panel dryness (TPD) is a complex physiological syndrome found widely in rubber tree (Hevea brasiliensis) plantations that causes severe yield loss in natural rubber-producing countries. In an earlier study, we confirmed that there is a negative correlation between HbMyb1 expression and TPD severity. To further investigate the function of HbMyb1 in TPD, HbMyb1 was over-expressed in tobacco controlled by a CaMV 35S promoter. In transgenic plants expressing HbMyb1, cell death induced by UV-B irradiation, paraquat and the hypersensitive reaction to necrotrophic fungal infection (Botrytis cinerea) was suppressed with a close correlation between HbMyb1 protein levels and the extent of suppression. In addition the nuclear condensation and degradation were observed in laticifer cells of TPD trees, while the nucleus of laticifer cells of healthy trees was morphologically normal. On the basis of the results described above, we propose that HbMyb1 maybe suppress stress induced cell death in rubber trees.
