Under drought stress condition, the signaling system induces expression of certain genes to counteract
the deleterious effects of environmental stress. Among the essential micronutrients for plant growth
and development, zinc has an important role in many plant metabolic processes including gene
expression and stress tolerance. In order to investigate the effect of drought stress and ZnO on relative
expression pattern of some genes involved in abiotic stresses (including WRKY1, HMA2 and ZIP1 genes)
in wheat cultivars, a factorial experimental was conducted in pot condition based on a completely
randomized design with three replications. In this experiment, the first factor was three levels of drought
stress (35, 60 and 85% of field capacity), the second factor was three wheat cultivars (including Heidari,
Meihan and Sysons), and the third factor was three levels of ZnO (0, 0.5 and 1 g/l-1). According to the
results, with increasing the level of drought stress, the relative expression of WRKY1 and ZIP1 genes
in drought tolerant cultivar (Meihan), and also with increasing nanoparticle concentration over stress
time, the expression of ZIP1 gene in drought sensitive cultivar (Sysons) increased. The highest relative
expression of HMA2 gene was observed in Heidari cultivar under mild drought stress. Generally, the
expression of all three genes studied in tolerant cultivar (Meihan) increased under drought stress.
Increasing the expression level of HMA2 and ZIP1 genes could be related to the transfer of zinc to
consuming tissues and also, to increase the consumption of zinc in current metabolism of plant, which
is important in tolerance of wheat to drought stress.