1 N. Khan, M. Mobin, F. Mohammad, F.J. Corpas, Eds. “Role of Nitric Oxide Action in Abiotic Responses in Plants” SPRINGER. 2014. Nitric oxide synthesis, detection methods and possible roles during jasmonate-regulated stress response. Palmiro Poltronieri* . Marco Taurino . Stefania Bonsegna . Stefania De Domenico . Angelo Santino CNR-ISPA, Institute of Sciences of Food Productions, via Monteroni, 73100 Lecce, Italy. *Palmiro.poltronieri@ispa.cnr.it Abstract In recent studies Nitric Oxide has been involved in modulation of signaling pathways under different conditions, in biotic and abiotic stress responses. NO synthesis, detection methods and mechanisms of action are briefly introduced. Studies on the comparison of jasmonates, OPDA, and ABA content and of gene expression variation in chickpea roots from a drought tolerant and a responsive variety, have extended studies made on drought and salt stress on other chickpea varieties, confirming the opinion of involvement of up-regulation of specific LOX, AOS and HPL isoforms. In this context, various levels of regulation of NO on jasmonate signaling and JA biosynthesis pathway are reviewed and discussed, sustained by the observations made in roots and nodules of salt stressed chickpea varieties. Finally, an additional level of regulation by epigenetics and microRNAs, with the involvement of Abscisic Acid and NO responsive elements in promoters of transcription factor genes, is briefly introduced. Keywords: Jasmonate signaling; Oxylipins; Nitric Oxide responsive promoters; ABA Responsive Elements (ABRE); microRNAs. 1. NO as a plant signaling modulator Nitrogen monoxide, or nitric oxide, is a free radical and a gasotransmitter involved in cell-to-cell communication. Nitric oxide (NO), carbon oxide (CO), and hydrogen sulphide (H 2 S), are volatile compounds, gasotransmitters permeable to cell membranes, being implicated in the communication between bacteria and roots, in regulation of root growth, and in plant-pathogen interactions.