Assessment of expression of some genes involved in cold tolerance in in lines of crosses between spring and winter wheat under cold acclimation periods

Low temperature stress is a kind of abiotic stress directly affecting growth and productivity of important agricultural products including wheat, worldwide. The purpose of the present study was to investigate the relationship between developmental regulation with low temperature tolerance, hydrogen peroxide (H2O2) accumulation and the expression of antioxidant enzymes genes in different phenological development stages in lines (RIL) of crosses between Pishtaz and Norstar wheat. Winter- and facultative-habit genotypes in the second period of low temperature acclimation, coinciding with the saturation range of the vernalization requirement, reached their maximum of low temperature tolerance, followed by a decrease in low temperature tolerance at the reproductive phase in third period of low temperature acclimation. Spring genotypes had very limited low temperature tolerance. Relative expression of TaVRT-1 gene in spring genotypes showed high and constitutively expression during low temperature acclimation periods. However, the relative expression of this gene in winter- and facultative-habit genotypes is expressed only after vernalization saturation. The relative expression of antioxidant enzymes genes were higher in winter- and facultative-habit genotypes than spring- habit genotypes, and reached its maximum in the second period of low temperature acclimation. Along with the increasing of relative expression of TaVRT-1 gene and decreasing antioxidant enzymes genes in the third period of cold acclimation, the accumulation of H2O2 reached maximum. Our results suggested that winter- and facultative-habit genotypes decreased the expression of TaVRT-1 gene and subsequently increased the length of the vegetative phase and the relative expression of antioxidant enzymes genes. Such reactions prevented the oxidative damage induced by low temperature stress and promoted more tolerant of low temperature.