Reactive oxygen species- Associated mechanism of acclamatory stress tolerance, signaling and redox-regulated gene expression in plants

Abstract

The conflict between the role of reactive oxygen species (ROS) as toxic component and as a central player of signaling network is largely unresolved. It is becoming evident that ROS and oxidative burst during any kind of stress are recognized by plant as signal molecule for triggering defense response. The molecular mechanism associated with ROSmediated signal transduction, leading to changes in gene expression, is one of the early responses in the acclamatory performance of plant. In Arabidopsis , a network of several genes is involved in managing the titer of ROS. This network of ROS-sensitive genes is highly dynamic and redundant that encodes redox-sensitive proteins and ROS- scavenging and ROS-producing molecules. The ROS-induced redox cues and associated retrograde signaling are extremely important in maintaining normal energy and metabolic fluxes, optimizing different metabolic and cellular functions, thereby controlling different acclamatory responses and ultimately the whole plant systemic signaling cascades. An overview of literature is presented on signaling role of ROS in plant acclamatory defense responses, along with their dynamics and specificity. In this context an effort has been made to update the concept of ROS signaling while addressing the significance of stress acclamatory performance of plants.