DNA methylation Pattern in shoot and root of barley under salinity stress

Salinity is one of the most crucial factors, which inhibits crop production. A large number of evidence reveal that epigenetic mechanisms modulate the gene expression in plants under abiotic stresses. Obviously, by understanding epigenetic regulation of plant growth and response to stresses, a heritable variation could be develop for crop breeding. In this study the DNA methylation alteration under salt stress analyzed in two barley cultivars differing in salt tolerance, namely Sahara3771 and Clipper. Coupled Restriction Enzyme Digestion-Random Amplification (CRED-RA) was utilized to detect CCGG sequence methylation alternation in shoot and root of the plants growing under o and 100 mM NaCl treatment. Leaf and root samples for DNA extraction were harvested 24 hours, 3 weeks, and 5 weeks after salt treatment. The results revealed that under salinity stress in shoot of Sahara3771 26.20% and 15.86% of sites were hypermethylated and demethylated respectively compared to control. Average number of hyper and demethylated sites in root of Sahara3771 were 74.7% and 38.9% respectively. In shoot of Clipper 17.02% of sites was hypermethylated and 11.74% of them demethylated. Average number of hyper and demethylated sites in root of Clipper were 67.10% and 5.7% respectively. Totally, number of methyl-changed sites in shoots was higher than roots in both genotype. In addition, number of methyl-unchanged sites in shoot of Sahara3771 was higher than Clipper. These results revealed that alteration of DNA methylation in plants could be a key factor in adaptation and toleration of plants to salinity.