Abstract
Under high salinity condition, plant growth is inhibited due to osmotic and ionic stresses. Especially, the effect of osmotic stress is mainly observed during the initial phase of salt stress treatment. To investigate the effects of osmotic stress caused by salt stress, we compared expression profilings at 1 h and 24 h of 20% PEG and 200 mM NaCl stresses using barley cDNA microarray carrying 460 stress-responsive genes. During the initial phase of osmotic and salt stresses, 22 and 62 genes were up-regulated, and 30 genes were down-regulated, respectively. Furthermore, we found the commonly regulated candidates, 18 up-regulated and 16 down-regulated genes, suggesting these expressions are modulated by osmotic stress signaling under salt stress. On the other hand, we also found the differentially regulated genes under osmotic or salt stress, and this indicated the complexity in regulation of gene expression under osmotic and salt stresses.
