Salicylic acid activates nitric oxide synthesis in Arabidopsis

• Published in: Journal of experimental botany Vol. 58; no. 6; pp. 1397 - 1405
• Main Authors: Zottini, Michela, Costa, Alex, De Michele, Roberto, Ruzzene, Maria, Carimi, Francesco, Lo Schiavo, Fiorella
• Format: Journal Article
• Language: English
• Published: Oxford Oxford University Press 01.01.2007; Oxford Publishing Limited (England)
• Subjects: Arabidopsis - drug effects; Arabidopsis - metabolism; Arabidopsis thaliana; Atnos1; Biological and medical sciences; Calcium; casein kinase 2; Cell Line; Cultured cells; Enzyme Inhibitors - pharmacology; Fluorescence; Fundamental and applied biological sciences. Psychology; Genes. Genome; Molecular and cellular biology; Molecular genetics; nia1; nia2; nitrate reductase; Nitrates; nitric oxide; Nitric Oxide - biosynthesis; Nitrites; omega-N-Methylarginine - pharmacology; Oxides; Plant cells; Plants; Reactive oxygen species; Research Papers; Salicylic Acid - pharmacology; salicylic acid signals; Seedlings; Spectrophotometry; Arabidopsis thaliana; nia1,nia2; nitric oxide; Atnos1; nitrate reductase; casein kinase 2; salicylic acid signals; Salicylic acid; Enzyme; Transferases; Casein; Cruciferae; Kinase; Nitrate reductase; Dicotyledones; Nitric oxide; Angiospermae; Spermatophyta; Oxidoreductases
• ISSN: 0022-0957; 1460-2431
• DOI: 10.1093/jxb/erm001

The relationship between nitric oxide (NO) and salicylic acid (SA) was investigated in Arabidopsis thaliana. Here it is shown that SA is able to induce NO synthesis in a dose-dependent manner in Arabidopsis. NO production was detected by confocal microscopic analysis and spectrofluorometric assay in plant roots and cultured cells. To identify the metabolic pathways involved in SA-induced NO synthesis, genetic and pharmacological approaches were adopted. The analysis of the nia1,nia2 mutant showed that nitrate reductase activity was not required for SA-induced NO production. Experiments performed in the presence of a nitric oxide synthase (NOS) inhibitor suggested the involvement of NOS-like enzyme activity in this metabolic pathway. Moreover, the production of NO by SA treatment of Atnos1 mutant plants was strongly reduced compared with wild-type plants. Components of the SA signalling pathway giving rise to NO production were identified, and both calcium and casein kinase 2 (CK2) were demonstrated to be involved. Taken together, these results suggest that SA induces NO production at least in part through the activity of a NOS-like enzyme and that calcium and CK2 activity are essential components of the signalling cascade.