This collection focuses on the function of reactive oxygen and nitrogen species in plant growth and development, defense systems, stress resistance, and detection methods. We invite submissions of original research articles, reviews, opinions, and perspectives under, e.g., the following subthemes: Crosstalk between the ROS/RNS and phytohormone signaling processes in plants Antioxidant regulatory networks in the regulation of ROS and RNS molecules Role of ROS and RNS in plant growth and molecular physiology Molecular function of ROS and RNS in seed emergence and stress tolerance Interaction between nanomaterials and ROS and RNS in plant growth, yield and stress tolerance Molecular analysis and novel detection methods of ROS and RNS production in plant systems Signal transduction activity of ROS, RNS in regulation of post-translational modification of proteins by S-glutathionylation and S-nitrosylation Crosstalk between ROS, RNS and calcium signaling System approaches (transcriptomics, proteomics, epigenomics and metabolomics) to examine the role of ROS and RNS impact on biochemical, physiological, and molecular responses of plants Role of ROS and RNS in response to environmental stresses, including heavy metal stress