Reactive Oxygen Species: Role in Senescence and Signal Transduction

Abstract

Reactive oxygen species (ROS) play a dual role in the plant kingdom. Previously, they were recognized as an inevitable toxic byproduct of cellular metabolism but accepted as a central regulator of important signaling events in cells. ROS participates in several biological processes like seed germination, cell division and differentiation, pollen tube development, growth of root hair, and programmed cell death. Moreover, they participate in several redox processes; conversely, at the same time, ROS induces oxidative stress, thereby prompting a physiological or programmed cell death. The homeostasis between ROS generation and eradication is managed, and the signals conveyed to the cells to initiate senescence in plant cells or organs are yet to be revealed. The current chapter focuses on how ROS contributes to senescence and redox signaling in plants besides sustaining cellular proliferation and physiological function.