Quantitative expression analysis of different cold-responsive (COR) and C-repeat binding factors (CBF) genes in wild and cultivated barley under cold acclimation conditions

Abstract

Cold stress affects plant metabolism and transcripts. The effect on plant metabolism was caused both by direct inhibition of metabolic enzymes at cold temperatures and by reprogramming the gene expression. The main objective of this study was to evaluate and identify of expression level of some cold-related genes under control and cold stress conditions in 11 spring/winter barley (Hordeum vulgare L.) varieties and 2 Hordeum spontaneum wild genotypes. For this purpose, expression profile of the main C-repeat binding factor )CBF( genes along with expression profiles of the two cold-responsive )COR( genes in plants exposed to low temperatures (+4 °C) were investigated. In parallel, measurements of leaf water potential of varieties were performed in control and at low temperature conditions. Results revealed that, the expression level changes of COR14b gene under cold conditions are more consistent with those of the upstream CBF9 gene expression levels in different varieties and time points rather than the other upstream gene (CBF1). The dehidrin8 )DHN8( expression level was also related to the CBF9 gene expression level and the decreased expression of the CBF9 gene resulted in decreased expression or non-expression of the DHN8 gene. Based on results, it could be said that CBF9 interacts with CBF1 to regulate DHN8 expression. Wild genotypes showed statistically insignificant expression increment for investigated genes in days 1 and 8 of stress. This result is an indicator of the increase at expression levels in the stress genes of more tolerant varieties