The effect of salinity stress on the expression pattern of SOS1 and NHX1 genes in susceptible and tolerant cultivars of wheat crop

Surveying the response and evaluating the salinity tolerance of wheat crop at the molecular level can be considered an important strategy in perception and comparing the defense mechanisms of wheat cultivars. For this purpose, a factorial experiment was conducted at Gorgan university of agricultural sciences and natural resources based on a completely randomized design with three replications in which the experimental factors were included wheat crop cultivars (Sarc 6 as tolerant cultivar and Chinese spring as susceptible cultivar) and sampling time series (control or 0, 24, 48, 72, 96 h after stress). In this experiment, salinity stress with a concentration of 250 mM of sodium chloride was applied to uniform 10-day seedlings in the two-leaf stage, and sampling of root and shoot tissues was performed. Then the amount of sodium and potassium ions and the relative expression of SOS1 and NHX1 genes were measured by the qPCR method in the following. The obtained results indicated that after applying salinity stress, the amount of Na+ in the shoot and root of both cultivars had raised trend with increasing sampling time. But about in the amount of K+, depending on the plant organ, the response of the two cultivars and the trend of variations were different. Also the results showed that the expression pattern of SOS1 and NHX1 genes in the shoot and root of both cultivars, did not have a regular trend. In general, it can be concluded that in the root of the Sarc 6 cultivar, faster and more accumulation of genes transcript was evident. This issue indicates that the essential role of these genes in the root for reducing sodium ion absorption and establishing ionic homeostasis.