Quantitative investigation of expression pattern and in silico analysis of regulatory elements in promoter region of sugar transporter (SuT4) gene under cold hardening in wheat (Triticum aestivum L.)

Freezing tolerance will be induced in most of the plants when they expose to non-freezingtemperatures. This process is called cold hardening. Several studies showed that, expression of cold regulated genes in plants is necessary for cold tolerance and hardening. In present study, expression pattern of a differentially expressed gene under cold hardening belonged to sugar transporter group (SuT4) was investigated in freezing susceptible and tolerant varieties of wheat. Additional study was performed on 5'-upstream region (promoter) of this gene. 4ºC was used to induced hardening treatment on 2- weeks old seedling. Sampling was carried out before and after hardening treatment.Quantitative real-time PCR approach was used to evaluate gene expression pattern using SYBR Green dye. The sequence of promoter region of gene was isolated and evaluated by genome walking based on PCR and PlantCARE and PLACE softwares Based on the results, SuT4 was up-regulated significantly in first day after hardening in both variety compared to non-treated plants but its expression was higher in tolerant variety than susceptible one over the experiment. The gene has promoter with 1980 bp and without TATA and CAAT box. The promoter contained many putative cis-acting regulatory elements, including abscisic acid (ABA)- responsive element, dehydration-responsive element, low-temperature responsive element and many other regulatory elements. Because of the expression of SuT4 was increased significantly in both variety, this gene may has been a role only in cell adaptation under stress condition or has a dual role to control cold stress and snow mold resistance.