Cytosine DNA methylation is a stable epigenetic mark for maintenance of gene silencing across cellular divisions, but it is a reversible modification. Genetic and biochemical studies have revealed that the Arabidopsis DNA glycosylase domain-containing proteins ROS1 (REPRESSOR OF SILENCING 1) and DME (DEMETER) initiate erasure of 5-methylcytosine through a base excision repair process. The Arabidopsis genome encodes two paralogs of ROS1 and DME, referred to as DEMETER-LIKE proteins DML2 and DML3. We have found that DML2 and DML3 are 5-methylcytosine DNA glycosylases that are expressed in a wide range of plant organs. We analyzed the distribution of methylation marks at two methylated loci in wild-type and dml mutant plants. Mutations in DML2 and/or DML3 lead to hypermethylation of cytosine residues that are unmethylated or weakly methylated in wild-type plants. In contrast, sites that are heavily methylated in wild-type plants are hypomethylated in mutants. These results suggest that DML2 and DML3 are required not only for removing DNA methylation marks from improperly-methylated cytosines, but also for maintenance of high methylation levels in properly targeted sites.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1007/s11103-008-9346-0 | DOI Listing |
Chemosphere
October 2023
Guangxi Key Laboratory of Agro-environment and Agric-products Safety, Key Laboratory of Crop Genetics Breeding and Germplasm Innovation, College of Agriculture, Guangxi University, Nanning, 530004, China. Electronic address:
Glutathione (GSH) participates in plant response to heavy metals (HMs) stress, however, the epigenetic regulating mechanisms of GSH in HMs detoxification remains unclear. In this study, to reveal the potential epigenetic regulating mechanisms, kenaf seedlings were treated with/without GSH under chromium (Cr) stress. A comprehensive physiological, genome-wide DNA methylation and gene functional analysis were performed.
View Article and Find Full Text PDFJ Integr Plant Biol
December 2022
National Institute of Biological Sciences, Beijing, 102206, China.
Although the Trithorax histone methyltransferases ATX1-5 are known to regulate development and stress responses by catalyzing histone H3K4 methylation in Arabidopsis thaliana, it is unknown whether and how these histone methyltransferases affect DNA methylation. Here, we found that the redundant ATX1-5 proteins are not only required for plant development and viability but also for the regulation of DNA methylation. The expression and H3K4me3 levels of both RNA-directed DNA methylation (RdDM) genes (NRPE1, DCL3, IDN2, and IDP2) and active DNA demethylation genes (ROS1, DML2, and DML3) were downregulated in the atx1/2/4/5 mutant.
View Article and Find Full Text PDFStress Biol
August 2022
Key Laboratory of Germplasm Enhancement, Physiology and Ecology of Food Crops in Cold Region of Chinese Education Ministry, College of Agriculture, Northeast Agricultural University, Harbin, 150030, Heilongjiang, China.
DNA methylation is an important epigenetic marker for the suppression of transposable elements (TEs) and the regulation of plant immunity. However, little is known how RNA viruses counter defense such antiviral machinery. In this study, the change of DNA methylation in turnip mosaic virus (TuMV)-infected cells was analyzed by whole genome bisulfite sequencing.
View Article and Find Full Text PDFJ Genet Genomics
August 2022
State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, Hubei 430070, China; The Provincial Key Lab of Plant Pathology of Hubei Province, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, China; Hubei Hongshan Laboratory, Wuhan, Hubei 430070, China. Electronic address:
Plants recognize microbe-associated molecular patterns (MAMPs) to activate immune responses and defense priming to defend against pathogen infections. Transcriptional regulation of gene expression is crucial for plant immunity and is mediated by multiple factors, including DNA methylation. However, it remains unknown whether and how DNA demethylation contributes to immune responses in MAMP-triggered immunity.
View Article and Find Full Text PDFPlant Cell
March 2022
Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA.
Cytosine methylation is a reversible epigenetic modification of DNA. In plants, removal of cytosine methylation is accomplished by the four members of the DEMETER (DME) family of 5-methylcytosine DNA glycosylases, named DME, DEMETER-LIKE2 (DML2), DML3, and REPRESSOR OF SILENCING1 (ROS1) in Arabidopsis thaliana. Demethylation by DME is critical for seed development, preventing experiments to determine the function of the entire gene family in somatic tissues by mutant analysis.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!