Evaluation of Some Physiological and Molecular Mechanisms of Wheat Cultivars Under Salt Stress

Abstract

Salt stress is an important problem in the cultivation of crops in dry and semi-arid environments, which restricts crop production. Considering that soil salinity in Iran and neighboring Turkey is increasing with decreasing celestial precipitation, it is important to select genotypes and tolerant wheat varieties for cultivated in saline soils by breeding for future generations. The present research was conducted to evaluate SOS2, SOS3, and SDH genes in wheat leaves using QRT-PCR. This experiment was done as a factorial in the form of a completely randomized design in each plot with three replications for four varieties. Bread wheat seedlings (Triticum aestivum L.) varieties including Kavir, Roshan, Bam, and a native landrace (3623) were screened by 200 mM NaCl for 10 days, and physiological and molecular parameters analysis of chlorophyll contents, fluorescence, cations, and proline contents for SOS2, SOS3, and SDH genes expression. Generally, salt stress significantly enhanced ions and organic compounds content (Calcium and sodium concentration), chlorophyll and carotenoid pigment, and the amino acid concentration of proline and chlorophyll fluorescence indices in varieties. Analyses revealed that 3623 can be regarded as a relatively "tolerant" genotype compared with the Kavir. After studying its agricultural indice, it will be considered for breeding programs. Overall, NaCl treated wheat, inducing salt-tolerance genes, effectively facilitates deficiency tolerance. Considering the expression of relatively higher TaSOS2 and TaSOS3 in the root of 3623 under stress conditions, perhaps most of the sodium absorbed by the root is returned to the environment.