Cellular Responses Against Abiotic Stress-Induced Reactive Oxygen Species

This chapter explores molecular mechanisms underlying behind molecular pathways triggered by excessive reactive oxygen species (ROS) production due to stress signalling. Abiotic stressors that disrupt redox equilibrium and jeopardise cellular integrity usually includes dehydration, salinity, heavy metals, high temperatures, and UV radiation. These conditions also cause ROS buildup. The chapter examines the various pathways and regulatory mechanisms that underlie the generation of reactive oxygen species (ROS) in plants exposed to abiotic stress, focusing on the critical roles played by peroxisomes, mitochondria, NADPH oxidases, and chloroplasts. It draws attention to the diverse networks of signalling and stress-responsive pathways that are involved in ROS-mediated signalling, including calcium signalling, transcription factors like AP2/ERF, WRKY, and NAC, and mitogen-activated protein kinases, that coordinates with gene expression and stress responses. The chapter also covers the complex systems of antioxidant defense, which include both enzymatic and non-enzymatic antioxidants, and how they work together to reduce oxidative damage and scavenges ROS buildup. Understanding the underlying effects of ROS-induced cellular damage on membranes, proteins, DNA, and organelles is also discussed, along with an explanation of the consequences for plant growth, development, and yield. This thorough investigation of the generation of reactive oxygen species (ROS) and molecular reactions triggered by abiotic stress lays the groundwork for comprehending the mechanisms underlying plant resilience and presents opportunities for developing stress-tolerant crops to maintain global food security in the face of shifting environmental conditions.