Role of Hydrogen Peroxide in Regulation of Photosynthesis and Its Crosstalk with Other Phytohormones under Abiotic Stress

Abstract

Hydrogen peroxide (H2O2) is recognized as a type of reactive oxygen species and serves as a crucial regulatory component involved in signal transduction in plants. H2O2 is not merely a byproduct of oxidative stress but also aids in maintaining cellular balance in crop plants. H2O2 plays a pivotal role in regulating stress defenses and secondary metabolic functions in plants. Exogenously applied H2O2 at nanomolar concentrations acts as a signaling molecule, promoting seed germination, chlorophyll production, stomatal opening, and delaying senescence. However, elevated levels of H2O2 can trigger oxidative stress leading to cellular damage and even cell death. Additionally, H2O2 interacts synergistically or antagonistically with other phytohormones such as auxins, gibberellins, cytokinins, abscisic acid, ethylene, salicylic acid, nitric oxide, and brassinosteroids under abiotic stresses. This chapter discuss the intricate role of hydrogen peroxide in mediating photosynthetic responses and abiotic stress tolerance, as well as its crosstalk with other phytohormones, underscores its significance in plant biology. Its dual nature as a signaling molecule and a reactive oxygen species highlights its multifaceted involvement in plant adaptation and resilience. Further exploration of these interactions promises valuable insights into enhancing crop productivity and stress resilience in the face of changing environmental conditions.