Abstract
When plants are exposed to various abiotic stresses, they respond and adapt to these stresses. DREB1A/CBF3 is one of cold-inducible genes encoding transcription factors in Arabidopsis. Overexpression of DREB1A caused increased tolerance to cold stress in Arabidopsis, indicating that the DREB1A protein functions in cold stress-responsive gene expression. Many protein products regulated by DREB1A are probably responsible for the stress tolerance of plants.
In this study, we analyzed genes for novel membrane protein family, COR413s whose expression is regulated by DREB1A. We confirmed that the COR413 genes, COR413-IM1, COR413-IM2.1, and COR413-PM1 were cold inducible by using RNA gel blot analysis. We observed the subcellular localization patterns of the proteins by using GFP fusion genes. COR413-IM1 and COR413-IM2.1 were localized at the chloroplast membrane, while COR413-PM1 was thought to be localized at ER. We analyzed phenotypes of T-DNA insertion mutants of these genes and found that cor413-im1 and cor413-im2.1 mutants accumulated more anthocyanin as compared to the wild-type plants under cold stress condition. We performed microarray and metabolome analyses using these mutants.
