DNA methylation (5-methylcytosine, m⁵C) is involved in gene silencing at both transcriptional and posttranscriptional levels. In eukaryotes, m⁵C is primarily found in the CG sequence, but in plants a large fraction of methylation is also present in the CNG sequence context [1]. The typical plant genome contains of relatively high levels of m⁵C, ranging from 6-25% of total amount cytosines, depending on a species [2]. m⁵C as a normal epigenetic component of cellular DNA can be modified by deamination or demethylation. These reactions lead to thymine (T) or cytosine (C) respectively. Other damaged products of m⁵C are also possible [3] and are recognized and repaired. However this is not the case for T and C, which are major components DNA. That is a reason of a point mutations and changes in genetic expression pattern.

Taking into account a regulatory role of m⁵C, we decided to analyze the amount of m⁵C in DNA from normal and damaged plant tissues. Genomic DNA was isolated from wounded and non-wounded maize leaves. After DNA hydrolysis nucleotides were labeled with [³²P]ATP and separated with thin layer chromatography [3].

The obtained results have shown that wounding of maize leaves has changed the level of methylated cytosine m⁵C in DNA. It suggests that stress responses of plants, including wounding, results in alternation of the DNA methylation and changes in gene expression pattern.

1. Chan S.W., Henderson I.R., Jacobsen S.E. (2005) Gardening the genome. DNA methylation in Arabidopsis thaliana. Nat. Rev. Genet. 6: 351-360.

2. Steward N., Ito M., Yamakuchi Y., Koizumi M., Sano H. (2002) Periodic DNA methylation in maize nucleosomes and demethylation by environmental stress. J. Biol. Chem. 277: 37741-37746.

3. Zukiel R., Nowak S., Wyszko E., Rolle K., Gawronska I., Barciszewska M.Z., Barciszewski J. (2006) Suppression of human brain tumor with interference RNA specific for tenascin-C. Cancer Biol. Ther. 5: 1002-1007.

• Legal notice:
  

  Copyright (c) Pielaszek Research, all rights reserved.
  The above materials, including auxiliary resources, are subject to Publisher's copyright and the Author(s) intellectual rights. Without limiting Author(s) rights under respective Copyright Transfer Agreement, no part of the above documents may be reproduced without the express written permission of Pielaszek Research, the Publisher. Express permission from the Author(s) is required to use the above materials for academic purposes, such as lectures or scientific presentations.
  In every case, proper references including Author(s) name(s) and URL of this webpage: https://science24.com/paper/11183 must be provided.

1. Human brain tumor therapy through interference RNA intervention
2. Plants defense mechanisms in response to wounding
3. The activity of the tetraloop:tetraloop receptor stabilized hammerhead ribozyme
4. Protein kinases involved in abiotic stress response in plants
5. The Role of Water Structure in Conformational Changes of Nucleic Acids in Ambient and High Pressure Conditions
6. High Pressure Effects on Nucleic Acids Properties