Cross-talk between ROS and phytohormones signaling determines crop sensitivity against ozone

Abstract

The prevailing tropospheric ozone (O3) concentration is escalating the productivity loss of crop and vegetables due to enhanced oxidative stress. Ozone itself is very reactive and can interact with mesophyll regions and components of cell walls after gaining entry from stomata. Apoplastic O3 activates a number of signal transduction pathways that regulate the cellular response to increased reactive oxygen species (ROS) load. The overproduction of ROS under O3 stress causes lesions as a hypersensitive or defensive response in the leaves of the sensitive plant. Ozone induced phytohormone signaling interacts with ROS signaling to change the plants’ performance in various aspects of plant physiology and metabolism. High O3 exposure promotes the accumulation of salicylic acid, which is essential for maintaining the cellular redox state and is important for plant defense responses. Salicylic acid concentration helps in regulating the production of ethylene during O3 exposure, which alters the magnitude of chlorotic spots on leaf surfaces. The review summarizes some recent findings about the target sites for O3 in plants, O3 induced stomatal regulation by phytohormone signaling, and plants’ responses related to phytohormone biosynthesis, ROS generation and signaling in exposure to O3. © 2023