Cadmium-induced genomic instability in Arabidopsis: Molecular toxicological biomarkers for early diagnosis of cadmium stress. (May 2016)

• Record Type: Journal Article
• Authors: Wang, Hetong; He, Lei; Song, Jie; Cui, Weina; Zhang, Yanzhao; Jia, Chunyun; Francis, Dennis; Rogers, Hilary J.; Sun, Lizong; Tai, Peidong; Hui, Xiujuan; Yang, Yuesuo; Liu, Wan
• Is Part Of: Chemosphere. Volume 150(2016)
• Page Start: 258
• Page End: 265
• Publication Date: 2016-05
• Subjects: Microsatellite instability -- Random-amplified polymorphic DNA -- Methylation-sensitive arbitrarily primed PCR -- Cadmium -- Arabidopsis thaliana; Pollution -- Periodicals; Pollution -- Physiological effect -- Periodicals; Environmental sciences -- Periodicals; Atmospheric chemistry -- Periodicals; 551.511
• DOI: 10.1016/j.chemosphere.2016.02.042
• Languages: English
• ISSNs: 0045-6535

Abstract

Abstract: Microsatellite instability (MSI) analysis, random-amplified polymorphic DNA (RAPD), and methylation-sensitive arbitrarily primed PCR (MSAP-PCR) are methods to evaluate the toxicity of environmental pollutants in stress-treated plants and human cancer cells. Here, we evaluate these techniques to screen for genetic and epigenetic alterations of Arabidopsis plantlets exposed to 0–5.0 mg L −1 cadmium (Cd) for 15 d. There was a substantial increase in RAPD polymorphism of 24.5, and in genomic methylation polymorphism of 30.5–34.5 at CpG and of 14.5–20 at CHG sites under Cd stress of 5.0 mg L −1 by RAPD and of 0.25–5.0 mg L −1 by MSAP-PCR, respectively. However, only a tiny increase of 1.5 loci by RAPD occurred under Cd stress of 4.0 mg L −1, and an additional high dose (8.0 mg L −1 ) resulted in one repeat by MSI analysis. MSAP-PCR detected the most significant epigenetic modifications in plantlets exposed to Cd stress, and the patterns of hypermethylation and polymorphisms were consistent with inverted U-shaped dose responses. The presence of genomic methylation polymorphism in Cd-treated seedlings, prior to the onset of RAPD polymorphism, MSI and obvious growth effects, suggests that these altered DNA methylation loci are the most sensitive biomarkers for early diagnosis and risk assessment of genotoxic effects of Cd pollution in ecotoxicology. Highlights: MSI occurred in Arabidopsis seedlings only under Cd stress of 8.0 mg L −1 for 15 d. Aberrations in DNA methylation were induced by Cd of 0.25–5.0 mg L −1 using MSAP-PCR. Sensitivity of biomarkers for Cd followed: DNA methylation loci >> RAPD > MSI. MSAP-PCR emerged as a powerful tool for early diagnosis of Cd stress.