Drought, high salinity, and low temperature are all environmental conditions that have an adverse effect on the growth of plants and the productivity of crops. Plants have adapted to respond to these stresses at the molecular and cellular levels as well as at the physiological and biochemical levels, thus enabling them to survive. Expression of a variety of genes is induced by these stresses in various plants. The products of these genes function not only in stress tolerance but also in the regulation of gene expression and signal transduction in stress responses.

Abscisic acid (ABA) is produced under water-deficit conditions and plays an important role in the plant response to drought and high-salinity stresses. Exogenous application of ABA also induces a number of genes that respond to dehydration and cold stress. Nevertheless, the role of ABA in cold stress-responsive gene expression is not clear. Several reports have described genes that are induced by dehydration and cold stresses but that do not respond to exogenous ABA treatment. This suggests the existence of ABA-independent, as well as ABA-dependent, signal transduction cascades between the initial stress signal and the expression of specific genes. The molecular mechanisms regulating gene expression in response to dehydration and cold stresses have been studied by analyzing the cis- and trans-acting elements that function in ABA-independent and ABA-responsive gene expression during the stresses in Arabidopsis.

We have analyzed transcription factors and cis-acting elements in stress-inducible promoters in order to find out transcriptional regulation of gene expression in response to environmental stresses in various crop plants. We hope that developing transgenic crop plants with environmental stress tolerance will improve agricultural productivity and environment conservation in the world. Please visit the "Publication" page to see our research activities.