Expression of nitric oxide synthase (NOS) from a marine photosynthetic microorganism in Arabidopsis thaliana

DEL CASTELLO FIORELLA; ANDRÉS NEJAMKIN; CORREA ARAGUNDE NATALIA; LAMATTINA LORENZO; FORESI, NOELIA PAMELA

Rosario

Simposio; Simposio de Genómica Funcional de Plantas; 2017

IBR, CONICET-UNR

Nitric oxide synthase (NOS) catalyzes the biosynthesis of nitric oxide (NO), a signal molecule in diverse biological processes, through the oxidation of the substrate L-arginine. We identified a NOS in the cyanobacteria Synechococcus PCC 7335 (SyNOS). SyNOS possesses both oxygenase and reductase domains as animal NOS, and an extra N-terminal globin domain with unknown function. Synechococcus is able to express SyNOS protein and produce NO in normal culture conditions. NO production in the cyanobacteria is inhibited by the addition of the specific NOS inhibitor L-NAME. The enzymatic activity of recombinant SyNOS is comparable with other bacterial NOS. Results show that E. coli cells expressing SyNOS grow in media containing L-arginine as unique nitrogen (N) source, indicating a possible participation of SyNOS-mediated NO production in N metabolism and/or assimilation. SyNOS was used for transforming Arabidopsis thaliana. The presence of the transgene was detected by PCR using specific primers, and transcript and protein by qPCR and immunoblot, respectively. We are currently analyzing the impact of the SyNOS expression in plant growth and development, especially against adverse environmental conditions and deficient N availability.