Chapter 9 - Regulatory role of nitric oxide in plants and its crosstalk with phytohormones

Abstract

Nitric oxide (NO) is a signaling oxido reductive gasotransmitter molecule that has specific effects within different plant species from germination to maturation. It exhibits several interactions with other molecules like reactive oxygen species (ROS), calcium (Ca2+), and hydrogen sulfide (H2S) associated with various signaling pathways that are linked to acclimatization or modification against stresses in plants. NO signal transductions are mediated by genes that control NO's bioactivity within plant cells. NO-induced regulation and signaling of phytohormones activate the defense system of plants by mediating ion homeostasis, stomatal and metabolic modifications for the growth and development of plants. Phytohormones are also a robust tool for effectively mitigating various stresses in plants. The crosstalk of NO and phytohormones is involved in an array of signaling networks, including Auxin, Gibberellin (GA), Abscisic acid (ABA), Melatonin, Salicylic acid, Jasmonic acid, Cytokinin, Brassinosteroids, Ethylene, etc., in stressed plants. This chapter includes the bioactivity, metabolism, and regulation of NO in plants under various stresses like heavy metal stress, salinity stress, temperature stress, and drought stress. Further, it also documents the crosstalk of NO and phytohormones under stress acclimatization.