Evolution of reactive oxygen species cellular targets for plant development.

Reactive oxygen species (ROS) are considered toxic substances causing oxidative damage in plants, but they are also important signaling molecules crucial for many developmental processes of root and leaf. The origin of many major ROS signaling target proteins is highly conserved, predating the evolution of land plants. ROS function for the regulation of root and leaf development with the presence of phytohormones, gasotransmitters, and target proteins, particularly mitogen-activated protein kinases (MAPKs). Reactive oxygen species (ROS) are the key players in regulating developmental processes of plants. Plants have evolved a large array of gene families to facilitate the ROS-regulated developmental process in roots and leaves. However, the cellular targets of ROS during plant evolutionary development are still elusive. Here, we found early evolution and large expansions of protein families such as mitogen-activated protein kinases (MAPK) in the evolutionarily important plant lineages. We review the recent advances in interactions among ROS, phytohormones, gasotransmitters, and protein kinases. We propose that these signaling molecules act in concert to maintain cellular ROS homeostasis in developmental processes of root and leaf to ensure the fine-tuning of plant growth for better adaptation to the changing climate. [ABSTRACT FROM AUTHOR]