Transgenerational increases in DNA methylation in Arabidopsis plants defective in active DNA demethylation.
Kai Tang, Xiaohong Zhu, Shaojun Xie, Zhaobo Lang, Jian-Kang Zhu
Author Information
Kai Tang: Department of Horticulture and Landscape Architecture, Purdue University, West Lafayette, IN 47907.
Xiaohong Zhu: State Key Laboratory of Crop Stress Adaptation and Improvement, School of Life Sciences, Henan University, Kaifeng 475004, China.
Shaojun Xie: Bioinformatics Core, Purdue University, West Lafayette, IN 47907.
Zhaobo Lang: Institute of Advanced Biotechnology and School of Medicine, Southern University of Science and Technology, Shenzhen 518055, China.
Jian-Kang Zhu: Institute of Advanced Biotechnology and School of Medicine, Southern University of Science and Technology, Shenzhen 518055, China. ORCID
Spontaneous gain or loss of DNA methylation occurs in plant and animal genomes, and DNA methylation changes can lead to meiotically stable epialleles that generate heritable phenotypic diversity. However, it is unclear whether transgenerational epigenetic stability may be regulated by any cellular factors. Here, we examined spontaneously occurring variations in DNA methylation in wild-type and mutant Arabidopsis plants that were propagated for ten generations from single-seed descent. We found that the mutant, which is defective in active DNA demethylation, showed an increased transgenerational epimutation rate. The mutation led to more spontaneously gained methylation than lost methylation at individual cytosines, compared to the wild type which had similar numbers of spontaneously gained and lost methylation cytosines. Consistently, transgenerational differentially methylated regions were also biased toward hypermethylation in the mutant. Our results reveal a genetic contribution of the ROS1 DNA demethylase to transgenerational epigenetic stability and suggest that ROS1 may have an unexpected surveillance function in preventing transgenerational DNA methylation increases.
