Transcription factors controlling the expression of oxidative stress associated genes in rice (Oryza sativa L.)

Reactive oxygen species (ROS) increases under stress and damages cellular processes leading to decrease in productivity. Many genes have been known to be involved in scavenging ROS. We report the identification of master regulators of oxidative stress responsive genes from contrasting rice genotypes. Using microarray analysis, we identified 52 differentially expressed transcription factors (TFs) from the contrasting rice genotypes under oxidative stress. Upregulation of these TFs induces the expression of many genes in resistant or sensitive genotypes. The promoters of these TFs are enriched with reactive oxygen species binding elements (ROSE). The promoter analysis of genes that respond to oxidative stress also revealed that these TF binding sites were present and that these genes expressed differently in contrasting rice genotypes. The transcript levels of TFs correlate with expression level of stress responsive genes coding for various pathways such as polyol, ABA, JA biosynthesis and signaling. Functional validation of HSF-C1a using virus-induced gene silencing (VIGS), showed reduced expression of its target genes. Our study demonstrates that identified TFs could act as major transcriptional regulators of oxidative stress tolerance. These TFs can be used as markers and are potential candidates to improve stress tolerance in plants.