Identification, bioinformatics evaluation and gene expression of DREB2 in local wheat of Kalak Afghani under salinity stress

Objective DREB gene family is one of the effective transcription factors in plant tolerance to environmental stresses, including salinity stress. The aim of this study is to identify and evaluate the expression of DREB2 gene in different salinity concentrations in local wheat of Kalak Afghan. Materials and methods Salinity stress treatment was applied to wheat using NaCl salt. Experimental treatments included different salinity levels (0, 100, 150, 200, 250 and 300 mM). Then RNA extraction and cDNA synthesis were performed and the specific fragment of DREB2 gene was amplified with specific primers. The obtained transcript was then sent for sequencing and the sequence was analyzed to identify the DREB2 gene. Results Partial sequence of DREB2 gene of local wheat of Kalak Afghani was registered in NCBI database with access number KR106189. The results of sequencing showed that the obtained sequence is more than 95% similar to the sequence of this gene in Triticum dicoccoides and Agropyrum elongatum. Examination of the second structure of DREB2 protein sequence through PSIpred and SOPMA programs showed that this sequence has 46 alpha helices (32.86%), 11 beta helices (7.86%), 9 long strands (6.43%) and 74 is a random helix (52.86%). The results of evaluation of DREB2 gene expression showed that the concentration of 100 mM salinity treatment, has a significant effect on increasing gene expression. In general, the highest effect on DREB2 gene expression was 100 mM salinity treatment and the lowest value was 300 mM. Conclusions In general, the DREB2 gene increases plant tolerance compared to other stress-induced genes, which makes them a desirable target for genetic engineering and crop performance. It seems that the reason that the expression of DREB2 gene does not increase at high concentrations is that the salt load is greater than the cells' ability to transmit it. Under these conditions, salt is transferred to the cytoplasm and inhibits enzymatic activities. Also, a common consequence of the accumulation of high concentrations of salt is the accumulation of large amounts of Reactive oxygen species (ROS), which can cause protein oxidation, damage to cellular DNA, lipid peroxidation, and interaction with other vital cell components. Leads to cell toxicity.