Reactive Oxygen Species-Driven Transcription in Arabidopsis under Oxygen Deprivation

Reactive oxygen species (ROS) play an important role as triggers of gene expression during biotic and abiotic stresses, among which is low oxygen (O₂). Previous studies have shown that ROS regulation under low O₂ is driven by a RHO-like GTPase that allows tight control of hydrogen peroxide (H₂O₂) production. H₂O₂ is thought to regulate the expression of heat shock proteins, in a mechanism that is common to both O₂ deprivation and to heat stress. In this work, we used publicly available Arabidopsis (Arabidopsis thaliana) microarray datasets related to ROS and O₂ deprivation to define transcriptome convergence pattern. Our results show that although Arabidopsis response to anoxic and hypoxic treatments share a common core of genes related to the anaerobic metabolism, they differ in terms of ROS-related gene response. We propose that H₂O₂ production under O₂ deprivation is a trait present in a very early phase of anoxia, and that ROS are needed for the regulation of a set of genes belonging to the heat shock protein and ROS-mediated groups. This mechanism, likely not regulated via the N-end rule pathway for O₂ sensing, is probably mediated by a NADPH oxidase and it is involved in plant tolerance to the stress.