Abstract
We investigated the tissue specific expression and DNA damage-responsiveness of AtRAD51 gene in Arabidopsis to uncover the mechanisms involved in regulated expression of the DNA damage-responsive gene. Transgenic Arabidopsis plants harboring AtRAD51 promoter-β-glucuronidase (GUS) were used to study the detailed expression pattern of the AtRAD51 gene. A histochemical GUS assay of bleomycin-treated plants showed that the AtRAD51 promoter in young tissues is actively expressed particularly in meristematic cells of the root and shoot apex of seedlings. In mature plants, the activity of the AtRAD51 promoter is mainly expressed in flower bud, petal and stigma. Reporter gene expression pattern similar to bleomycin-treated plants was also observed in UV-treated plants. In the absence of genotoxic stress, only very low GUS activities were detected in these organs. These results suggest that the tissue-specific expression levels of AtRAD51 gene promoter are also controlled by the DNA damage-responsive regulation.
