Nitric Oxide in Plants and its potential Impact on nitrogen assimilation

NEJAMKIN A; CORREA-ARAGUNDE N; LODEYRO A; MAYTA M; LAMATTINA L; FORESI N; FIORELLA DEL CASTELLO; CARRILLO N

Congreso; RAFV XXXI. Corrientes. Argentina.; 2016

Sociedad Argentina de Fisiologia Vegetal

Research on Nitric Oxide (NO) in plants has gained considerable attention in recent years mainly due to its function as a key signaling molecule in different intracellular processes in plant growth and development. In higher plants, there are at least two enzymatic sources of NO production: (i) nitrate reductase, that reduces nitrate to nitrite, and then nitrite to NO, and (ii) a putative NO Synthase (NOS-like) enzymatic activity, although no NOS gene or protein was found yet. In animals NOS catalyzes the formation of NO and citrulline from L-arginine in a reaction that uses NADPH as an electron donor and O2 as a co-substrate. In the Lamattina?s lab was characterized the first NOS in the plant kingdom from the unicellular algae Ostreococcus tauri (OtNOS). OtNOS possesses most of the characteristics ascribed to animal NOS. We transformed Nicotiana tabacum and Arabidopsis thaliana plants with OtNOS gene and studied the behaviour of different transgenic lines. Results indicate that a NOS-dependent NO production improves the growth, developmental and metabolic parameters of plants. These findings are reminiscent of a concerted action of NO that also includes an increase of N metabolism that might lead to improved nitrogen assimilation.