Effects of cold and short day treatments on dehydrin gene expression in seedlings and regenerated shoots of pistachio (Pistacia vera L.)

Cold stress is a major environmental factor that limits the agricultural products. Plants can increase their cold and freezing tolerance by being exposed to short days and cold, non freezing temperatures, a process known as cold acclimation. In the period of cold acclimation that causes dehydration of cells, dehydrin proteins accumulate inside the cells and protect the membranes and macromolecules structure. Pistachio (Pistacia vera L.) is a tree species characteristic of arid zone, which is exposed to extreme temperatures. In this study, the effects of cold and short day treatments on dehydrin gene expression were investigated in seedlings and regenerated shoots of pistachio cultivar Badami. The results showed that cold treatment increased the gene expression meaningfully compaired to the control. The short day treatments had no effect on dehydrin gene expression. Because the regenerated plants may encounter somaclonal variations and thus show different responses to stresses, a comparison was made between in vivo and in vitro grown plants with respect to the rate of gene expression, under similar cold treatment. Comparison of the plants grown in vivo and in vitro showed that dehydrin gene expression was lower in regenerated shoots under natural condition and after cold treatment.