Abstract:

Nitric oxide (NO) has been recently characterized as an important signal molecule that mediates many developmental and physiological processes in plant cells . NO can be generated from nitrite by nitrate reductase (NR) and arginine by NO synthaselike enzymes. NO induces various processes in plants, including seed germination, root development, inflorescence initiation, stomatal closure and abiotic and biotic stress responses . The redox chemistry of NO allows it to react with the haem groups, cysteine and tyrosine residues on target proteins, which result in post-translational protein modification, metal nitrosylation, S-nitrosylation, and tyrosine nitration. Intracellular signaling responses to NO also include generation of cyclic guanosine monophosphate, elevation of cytosolic calcium, and activation of mitogen-activated protein kinases. However, divergence and crosstalk of reactive oxygen species and NO signaling pathways occur in the plant response to hormone and stresses. Here, we provide a brief summary of new insights into NO signaling in plants and the cross-talk between reactive oxygen species and NO signaling.

Key words: development, nitric oxide, reactive oxygen species