DNA methylation changes in the root of barley under long and short-term salinity stress

Salinity is one of the most crucial factors, which inhibits crop production. Increasing evidence has revealed 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 developed 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 0 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 the root of Sahara3771, 9.92% and 14.69% of sites were hypermethylated and demethylated respectively compared to the control. The average number of hyper and demethylated sites in the root of Clipper was 11.34% and 12.76% respectively. In Sahara3771, the number of hypermethylated sites was 1.5 times higher than demethylated sites. In addition, number of methylunchanged sites in Sahara3771 was higher than Clipper. Methylation changes induced by increasing stress duration. Then, under long-term stress number of hyper and demethylated sites respectively increased in Sahara3771 and Clipper. These results revealed that alteration of DNA methylation in plants could be a key factor in adaptation and toleration of plants to salinity.

Keywords:

Barley , Salinity stress , Methylation pattern , CRED-RA