Morphological, Biochemical and Proline-Related Genes Analyses in Resistant and Susceptible Wheat Cultivars in Iraq

A high salinity level negatively affects the morpho-physiological parameters of plants. As a result of salinity, these effects are considered crucial signs of plant damage.  In this study, ten Iraqi wheat cultivars were examined against two salinity levels (3 and 15 ds m-1) and some morphological, biochemical properties were measured. Also proline-related genes were analyzed using Ilumina RNA sequences and bioinformatics analyses. All cultivars demonstrated a decrease in the studied parameters with an increase saliness. 'Dijlah' cultivar showed best performance salinity stress, while 'Ibaa 99' was sensitive based on morphological and biochemical parameters. The competition was in favor of the sodium ion at the expense of the potassium ion in high salinity conditions. Proline accumulation in wheat blade leaves was about 2.5 times higher at the peak salt level. The transcriptomic analysis was done and the transcripts per million (TPM) values were estimated for some proline genes. The genes of probable proline transporter 2, proline     dehydrogenase 2, and GSK-like kinase 1A obtained the higher TPM values in cultivar 'Dijlah' cultivar than in 'Ibaa 99' cultivar. It can be concluded that 'Dijlah' cultivar is a salt tolerant cultivar as compare with the susceptible 'Ibaa 99' cultivar, and their proline accumulation was increased with salinity stress and was related with TPM values.  Morphological, biochemical and TPM values would offer a good combined- criteria for recognition the tolerant genotype.