Redox‐sensitive bZIP68 plays a role in balancing stress tolerance with growth in Arabidopsis

Abstract

Summary 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 growth conditions in Arabidopsis seedlings. 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 under normal conditions 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.

Integrating ATAC-seq and RNA-seq Reveals the Dynamics of Chromatin Accessibility and Gene Expression in Apple Response to Drought

“…IDD7 plays a negative regulatory role in the growth and development of plants [ 31 ]. SPL13, bZIP68, and ZIM are involved in stress response and development in different plants [ 32 , 33 , 34 , 35 ]. These overlapped THSs-related transcription factors are clearly enriched in pathways involved in growth and development and may play additional roles during drought treatment.…”

“…Overlapping the THSs in the drought and control treatments revealed common chromatin open motif enrichment of TCP23, bZIP68, IDD7, TCP7, ZIM, and SPL13. These transcription factors are all involved in plant developmental processes [ 29 , 30 , 31 , 32 , 33 , 34 , 35 ], suggesting that the overlapping THSs act in processes related to plant growth or development. Simultaneous enrichment analysis of THSs-related genes specific to drought treatment showed enrichment of drought-specific genes related to RNA process protein phosphorylation and enrichment of control-specific genes related to development.…”

Superoxide is promoted by sucrose and affects amplitude of circadian rhythms in the evening

“…In Arabidopsis, redox-sensitive proteins that are oxidized by H 2 O 2 have been identified in most cellular compartments (38). These include plasma membrane receptors (39), glycolytic enzymes (38,40), which can localize in the nucleus and associate with DNA (41,42), and transcription factors (43) regulated transcripts indicate clear temporal separation of their effects (Fig. 4).…”

Specificity of H2O2 signaling in leaf senescence: is the ratio of H2O2 contents in different cellular compartments sensed in Arabidopsis plants?

“…Moreover, during the last two decades, it became evident that ROS, and especially hydrogen peroxide, can function as signaling molecules in developmental as well as stress-induced senescence. On the one hand, ROS can have a direct impact on gene expression by altering the expression as well as the activity of transcription factors [2,[30][31][32][33], thereby modulating regulatory processes. On the other hand, ROS can oxidize more or less all kinds of macromolecules, influencing a variety of physiological changes.…”