The homeostatic phyto-defense mechanism for reactive oxygen species under environmental stress conditions: A review

Abiotic stressors inhibit growth and development, which ultimately leads to low productivity and yield of the plants. Reactive oxygen species (ROS) signaling pathway has been demonstrated to be a crucial component of plants’ acclimatization responses to metal toxicity, salinity stressors, etc. Stressed plants experience oxidative stress, which is defined by a rise in intracellular and extracellular ROS in specific organelles. Through enhanced ROS synthesis at the apoplast by various respiratory burst oxidase homolog (RBOH) proteins, it is used to actively relay a variety of signals. It is also utilized to identify stress brought on by elevated ROS generation as a result of metabolic abnormalities. Under stress, ROS signaling pathway is intricately entwined with the signaling networks, including calcium, hormone, and protein phosphorylation networks, that control plant acclimation. Although the division of antioxidant activities into distinct compartments is well understood, further research is needed to understand how plants recognize, respond to, and balance ROS activity. We can infer, generally, from the many research conducted over the past 20 years that cross-talk between abscisic acid (ABA), Ca²⁺, and several other hormones and signaling molecules is necessary for ROS equilibrium. Furthermore, ROS activates gene cascades that support abiotic stress tolerance by acting as a signal transducer in a ROS-dependent manner. Genes like as protein kinases and transcription factors are important upstream elements that facilitate the activation of additional downstream genes involved in reducing ROS toxicity. The current review work has tried to give a summary of the mechanisms, both oxidative and non-oxidative, that contribute to abiotic stress tolerance and adaptation as well as the decrease of ROS damage.