Comparative expression analysis of dehydrins between two barley varieties, wild barley and Tibetan hulless barley associated with different stress resistance

Drought, salinity and cold are the major environmental factors impacting on survival and productivity of Tibetan hulless barley in Tibetan Plateau of China. Tibetan hulless barley cultivar, Tibetan Heiqingke No. 1, has developed a strong tolerance and adaptation to stresses in relation to the wild barley. The differences of dehydrin gene transcription and translation between Tibetan Heiqingke No. 1 and the wild barley under drought, salinity and low temperature stresses were investigated in the present study to figure out the putative mechanism of stress tolerance of Tibetan Heiqingke No. 1. The leaf relative water contents (RWCs) decreased more slowly in Tibetan hulless barley than the wild barley under osmotic and low temperature conditions. Electrolyte leakage, malondialdehyde and H2O2 contents increased faster in wild barley than those of Tibetan hulless barley, which indicated that cells of wild barley received more damages than Tibetan hulless barley. Furthermore, the expression of several dehydrin genes, belonging to four different classifications respectively, was also investigated. Polyclonal antibodies against dehydrins were obtained from rabbit after prokaryotic expression and purification of TDHN4, a dehydrin protein from Tibetan hulless barley. With these antibodies and dehydrin gene fragments, western blotting analysis and RT-PCR showed that Tibetan Heiqingke No. 1 accumulated higher abundance of dehydrins than stress-sensitive wild barley under all stress conditions.