Nitric oxide and reactive oxygen species in plant biotic interactions

•Nitric oxide and reactive oxygen species are major players of biotic interactions in plants.•Nitric oxide and reactive oxygen species signaling pathways are interdependent.•Nitric oxide and reactive oxygen species are crucial components of plant immunity. Nitric oxide (NO) and reactive oxygen species (ROS) are important signaling molecules in plants. Recent progress has been made in defining their role during plant biotic interactions. Over the last decade, their function in disease resistance has been highlighted and focused a lot of investigations. Moreover, NO and ROS have recently emerged as important players of defense responses after herbivore attacks. Besides their role in plant adaptive response development, NO and ROS have been demonstrated to be involved in symbiotic interactions between plants and microorganisms. Here we review recent data concerning these three sides of NO and ROS functions in plant biotic interactions.