Comparison of the genetic diversity levels of wheat species grown in Turkey & investigation of the genomic responses of local einkorn wheat to heat stress

Global climate is changing rapidly, affecting nearly all organisms, including plants. Wheat is one of the major crops worldwide and, like many other species, is adversely affected by climate change. Therefore, it is important to determine how wheat species respond to stress conditions at the molecular level to understand their adaptive potential for their future breeding and conservation. In this study, through ddRAD sequencing, adaptive potentials of local einkorn, emmer, and bread wheat were compared in terms of their genetic diversity levels. Consequently, three species were clearly separated based on their diversity levels, and the highest genetic distance was found between old (1995) and new (2015) einkorn (FST = 0.238923), indicating ex-situ conservation is more advantageous for einkorn in a changing climate than in-situ conservation. However, no distinction was observed for old and new emmer populations, suggesting the protection of emmer from genetic bottlenecks caused by climate change, most probably because of its ploidy. Through RNA sequencing, old and new einkorn were also compared in terms of their response to heat stress. When the genes differentially expressed between old and new einkorn at stress temperature were investigated, it was found that genes and gene sets involved in energy and stress-responsive protein production were enriched as well as the genes related to the regulation of physiological processes, membrane stability, and photosynthesis, whereas at control temperature a more general response was observed. These findings suggest that transcriptomic responses of einkorn diverged in 20 years of climate change, providing evidence for rapid evolution.