Theoretical and Applied Genetics

, Volume 95, Issue 1, pp 301–306

Hypermethylation of tobacco heterochromatic loci in response to osmotic stress

Authors

  • A. Kovar˘ik
    • Institute of Biophysics, Academy of Sciences of the Czech Republic, Královopolská 135, 612 65 Brno, Czech Republic
  • B. Koukalová
    • Institute of Biophysics, Academy of Sciences of the Czech Republic, Královopolská 135, 612 65 Brno, Czech Republic
  • M. Bezde˘k
    • Institute of Biophysics, Academy of Sciences of the Czech Republic, Královopolská 135, 612 65 Brno, Czech Republic
  • Z. Opatrn´
    • Research Institute of Crop Production, Ministry of Agriculture, Department of Plant Physiology and Molecular Biology, Drnovská 507, 161 00 Prague 6, Czech Republic

DOI: 10.1007/s001220050563

Cite this article as:
Kovar˘ik, A., Koukalová, B., Bezde˘k, M. et al. Theor Appl Genet (1997) 95: 301. doi:10.1007/s001220050563

Abstract

 Plants have to cope with a number of envi-ronmental stresses which may potentially induce genetic and epigenetic changes and thus contribute to genome variability. In the present study we inspected the DNA methylation status of two heterochromatic loci (defined with repetitive DNA sequences HRS60 and GRS) in a tobacco cell culture exposed to osmotic stress. Investigations were performed on a TBY-2 cell suspension culture, and the stress was elicited with NaCl or D-mannitol. Using the restriction enzymes MspI/HpaII and MboI/Sau3AI in combination with Southern hydridization we observed a reversible hypermethylation of the external cytosine at the CpCpG trinucleotides in cells grown under mild osmotic stress equal to a NaCl concentration of 10 g/l. There were no changes in the methylation of the internal cytosine as the CpG dinucleotides within the CCGG motifs (HpaII sites) appeared to be fully methylated in tobacco DNA repetitive sequences under normal physiological conditions. The data suggest epigenetic changes in the plant genome based on de novo methylation of DNA in response to environmental stress.

Key words DNA methylationRepetitive sequencesSalt stressTobacco

Copyright information

© Springer-Verlag Berlin Heidelberg 1997