Update on Reactive Oxygen Species Activation of Ca Channels Reactive Oxygen Species Activation of Plant Ca Channels. A Signaling Mechanism in Polar Growth, Hormone Transduction, Stress Signaling, and Hypothetically Mechanotransduction

Reactive oxygen species (ROS) are highly reactive reduced oxygen molecules. Recent studies have shown that production of ROS occurs in response to many physiological stimuli in plant cells, including pathogen attack, hormone signaling, polar growth, and gravitropism. Evidence is emerging that ROS can function as cellular second messengers that are likely to modulate many different proteins leading to a variety of responses. One target of ROS signal transduction is the activation of Ca-permeable channels in plant membranes. ROS activation of Ca channels may be a central step in many ROS-mediated processes, such as stress and hormone signaling, polar growth, development, and possibly during mechanotransduction.