Transgenerational variations in DNA methylation induced by drought stress in two rice varieties with distinguished difference to drought resistance

PLoS One. 2013 Nov 11;8(11):e80253. doi: 10.1371/journal.pone.0080253. eCollection 2013.

Abstract

Adverse environmental conditions have large impacts on plant growth and crop production. One of the crucial mechanisms that plants use in variable and stressful natural environments is gene expression modulation through epigenetic modification. In this study, two rice varieties with different drought resistance levels were cultivated under drought stress from tilling stage to seed filling stage for six successive generations. The variations in DNA methylation of the original generation (G0) and the sixth generation (G6) of these two varieties in normal condition (CK) and under drought stress (DT) at seedling stage were assessed by using Methylation Sensitive Amplification Polymorphism (MSAP) method. The results revealed that drought stress had a cumulative effect on the DNA methylation pattern of both varieties, but these two varieties had different responses to drought stress in DNA methylation. The DNA methylation levels of II-32B (sensitive) and Huhan-3 (resistant) were around 39% and 32%, respectively. Genome-wide DNA methylation variations among generations or treatments accounted for around 13.1% of total MSAP loci in II-32B, but was only approximately 1.3% in Huhan-3. In II-32B, 27.6% of total differentially methylated loci (DML) were directly induced by drought stress and 3.2% of total DML stably transmitted their changed DNA methylation status to the next generation. In Huhan-3, the numbers were 48.8% and 29.8%, respectively. Therefore, entrainment had greater effect on Huhan-3 than on II-32B. Sequence analysis revealed that the DML were widely distributed on all 12 rice chromosomes and that it mainly occurred on the gene's promoter and exon region. Some genes with DML respond to environmental stresses. The inheritance of epigenetic variations induced by drought stress may provide a new way to develop drought resistant rice varieties.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • DNA Methylation / genetics*
  • Droughts*
  • Gene Expression Regulation, Plant
  • Oryza / genetics*
  • Plant Proteins / genetics

Substances

  • Plant Proteins

Grants and funding

This research was supported by the National High-Tech Research and Development Program of China (863 Plan) (Grant No. 2012AA101102), National Natural Science Foundation of China (Grant no. 31200279), National Basic Research Program of China (973 Plan) (Grant No. 2012CB114305), the Postdoctoral Science Foundation of Shanghai (No. 12R21421300) and Talented Person Project (2010CI120). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.