[DNA damages and apoptosis induced by cd in the leaves of horsebean Vicia faba].

DNA damages and programmed cell death in leaves of Vicia faba induced by Cd were studied with methods including alkaline/alkaline, alkaline/neutral, neutral/neutral comet assay and DAPI staining. Types of DNA damages induced by Cd were different detected by three types of comet assay. Single strand breakage and alkali labile sites were detected in the leaves of Vicia faba with 5 mg x L(-1) Cd treatment by alkaline/alkaline comet assay. With 10 mg x L(-1) Cd treatments, double strand breakages began to be detected by neutral/neutral comet assay. However, single strand breakages and alkali labile sites were still the main types of DNA damages. Three types of DNA damages increased significantly with 20 mg x L(-1) Cd treatment especially double strand breakages. These results indicated that DNA damages increased with increasing of Cd concentration, which was consistent with the programmed cell death induced by Cd. The result of apoptosis detected by DAPI staining indicated that there existed a relationship between apoptosis and DNA damage. These results indicated that Cd was an element with high genotoxicity and DNA damage was one of the mechanisms of cell apoptosis induced by Cd.