Analysis of the chloroplast membrane localized protein controlled by an Arabidopsis transcription factor DREB1A involved in cold-responsive gene expression

Abstract

When plants are exposed to various abiotic stresses, they respond and adapt to these stresses. DREB1A is one of cold inducible genes encoding transcription factors in Arabidopsis. Overexpression of DREB1A/CBF3 caused increased tolerance to freezing in Arabidopsis, suggesting that the DREB1A/CBF3 protein functions in cold stress-responsive gene expression. Many protein products regulated by DREB1A/CBF3 are probably responsible for the stress tolerance of plants.
In this study, we analyzed genes for chloroplast membrane localized proteins regulated by DREB1A. We tested the cellular-localization pattern of these proteins by using GFP fusion constructs. Under normal condition, these proteins were localized at chloroplasts of guard cells. Under cold condition, we detected GFP fluorescence not only at guard cells but also at chloroplasts of mesophyll cells. We generated transgenic plants overexpressing these proteins, and determined the metabolites of the chloroplasts of the transformants.