Cadmium stress alters cytosine methylation status and expression of a select set of genes in Nicotiana benthamiana

• Published in: Plant science (Limerick) Vol. 284; pp. 16 - 24
• Main Authors: Xin, Cuihua, Chi, Junling, Zhao, Yibo, He, Yindi, Guo, Jiangbo
• Format: Journal Article
• Language: English
• Published: Ireland Elsevier B.V 01.07.2019
• Subjects: Cadmium; Cadmium - toxicity; Cytosine - metabolism; Cytosine methylation; DNA, Plant - drug effects; Gene Expression Regulation, Plant - drug effects; Genes, Plant - drug effects; Genotoxicity; Methylation - drug effects; MSAP; Nicotiana - drug effects; Nicotiana - genetics; Nicotiana - metabolism; Real-Time Polymerase Chain Reaction; Stress, Physiological - drug effects; VIGS; Cadmium; MSAP; Cytosine methylation; Genotoxicity; VIGS
• ISSN: 0168-9452; 1873-2259
• DOI: 10.1016/j.plantsci.2019.03.021

•The genotoxicity of Cd to N. benthamiana were investigated by MSAP and 14 candidate genes were isolated.•Four selected genes were intragenic methylated by genome blasting and alignment in database.•Expressions of four selected genes were related to Cd concentration exposed.•The impacts of Cd on alteration of cytosine methylation status in four selected genes were analyzed and confirmed by BSP.•N. benthamiana with silenced four selected genes showed hypersensitive to Cd exposure. In this paper, we evaluated the genotoxicity of cadmium (Cd) in plants by performing a methylation-sensitive amplification polymorphism (MSAP) on the model plant Nicotiana benthamiana. Among 255 loci examined, 14 genes were found to show altered cytosine methylation patterns in response to Cd stress. Four of those genes (NbMORC3, NbHGSNAT, NbMUT, and NbBG) were selected for further analysis due to their predicted roles in plant development. Cd-induced changes of cytosine methylation status in MSAP fragments of selected genes were confirmed using bisulfite sequencing polymerase chain reaction (BSP). In addition, the expression levels of these genes were found to correlate with cadmium dosage, and a knock-down of these four genes via virus-induced genes silencing (VIGS) led to abnormal development and elevated sensitivity to cadmium stress. Silencing of these four genes resulted in altered cadmium accumulation in different parts of the experimental plants. Our data indicate that cadmium exposure causes dramatic changes in the cytosine methylation status of the plant genome, thus affecting the expression of many genes that are vital for plant growth and are involved in cadmium stress response.