School of Agriculture Food and Wine, Plant Research Centre, Waite Campus, The University of Adelaide, PMB 1, Glen Osmond, SA 5064, Australia
Soil salinity is a major cause of yield loss in barley and other crops across the world. Salt concentration in the soil changes with position, depth, seasonal progression and farm management, and can reduce yield even at relatively low concentrations. During growth, plants need to adapt to these variations in salt levels in a quick and dynamic manner. This requires physiological adjustments, including osmotic balance, tolerance of Na+ toxicity or Na+ exclusion through leaves. We aimed to examine whether physiological adaptation was driven by epigenetic changes in genomic DNA. Methylation-sensitive Genotyping By Sequencing was used to screen the genome of five barley varieties exposed to increasing salinity levels for salt-specific epiloci. We found a number of epimarkers that collectively allowed highly significant separation of controls from plants exposed to salt stress. These epimarkers may be involved in regulation of genes crucial to barley adaptation to salinity. The implications of these findings for the selection of salt tolerant lines in commercial breeding efforts are explored.