Construction of in vivo Reporter Assay System to Monitor Genotoxic Stresses Based on AtRAD51 Promoter-Luciferase Gene Expression.

Abstract

In order to develop biological monitoring system as indicator to genotoxicity in plants, we investigated the use of DNA-damage responsive promoter from Arabidopsis. A 0.7 kb fragment of the 5'-upstream region of AtRAD51 genomic DNA was fused to the modified firefly luciferase (Fluc+) reporter gene and introduced into Arabidopsis, tobacco and BY-2 cells. To test the AtRAD51 promoter induction in response to DNA damage, we tested treatment with a radiomimetic agent, bleomycin, which produces DNA strand breaks. Treatments at various concentrations of bleomycin resulted in the induction of AtRAD51 promoter in a dose-dependent manner in transgenic plants and BY-2 cells. No detectable induction of the AtRAD51 promoter activity was observed with xenobiotic stresses including treatment with heavy metals, plant hormones and defense gene inducers.