GSE133900
Redox-sensitive bZIP68 plays a role in balancing stress tolerance with growth in Arabidopsis
Perturbation of the cellular redox state by stress conditions is sensed by redox-sensitive proteins so that the cell can physiologically respond to stressors; however, the mechanisms linking sensing to response remain poorly understood in plants. Here we report that the transcription factor bZIP68 underwent in vivo oxidation in Arabidopsis cells under oxidative stress which is dependent on its redox-sensitive Cys320 residue. bZIP68 is primarily localized to the nucleus under normal conditions in Arabidopsis seedlings and oxidative stress reduces its accumulation in the nucleus and increases its cytosolic localization. Chromatin immunoprecipitation followed by sequencing (ChIP-seq) revealed that bZIP68 primarily binds to promoter regions containing the core G-box (CACGTG) or G-box-like motif of the genes involved in abiotic and biotic stress responses, photosynthesis, biosynthetic processes, and transcriptional regulation. The bzip68 mutant displayed slower growth but enhanced tolerance to oxidative stress. The results from the ChIP-seq and phenotypic and transcriptome comparison between the bzip68 mutant and wildtype indicate that bZIP68 normally suppresses expression of stress tolerance genes and promotes expression of growth-related genes, whereas its inactivation enhances stress tolerance but suppresses growth. bZIP68 might balance stress tolerance with growth through the extent of its oxidative inactivation according to the environment. Overall design: Transcriptome and CHIP-seq of bzip68 mutants