Nitric Oxide and Cellular Redox Homeostasis in Plants

Abstract

Attributing to the diverse abiotic stresses and climate fluctuations, the agriculture sector is experiencing some serious misfortunes. This largely influenced the growth, yield, and functioning of crops and have further imposed constraints on food security worldwide. Plants confront various abiotic stresses that leads to the generation of reactive oxygen species (ROS) in different cell compartments and disturb the redox homeostasis of the cells. The ROS when produced at high levels, they are considered harmful to cells and cause cellular damage whereas, at significant levels, they act as signaling molecules to provide defense responses to plants. Under stress, the accumulation of ROS within the cell tends to create an imbalance between the generation of ROS and the production of antioxidant enzymes which sets off a disproportion in the amount of ROS that builds up oxidative stress and ultimately leads to damaging effects on the cell. To combat such conditions, nitric oxide (NO) being a small, bioactive, gaseous signaling molecule employed by plants to mitigate the effects of abiotic stresses. NO is a redox molecule that assist in the scavenging of excessive ROS by promoting the activities of antioxidant enzymes and osmolytes, interacting with sulfur-assimilation pathway, upregulating the ascorbate–glutathione cycle, and utilizing nitrogen metabolism for its synthesis and therefore regulates the growth, development, and functioning of plants. In this chapter, we have documented the recent advancements indicating the harmful nature of ROS that cause oxidative damage and how it alters the cellular homeostasis within plants along with highlighting the crucial strategies utilized by NO to manage the ROS levels to establish a toxic-free environment and aid in the improvement of plant defense responses.

Tanashvi Seth and Sejal Asija are contributed equally.