Nitric oxide (NO) as a plant growth regulator: impact of NO research in plant roots

CORREA ARAGUNDE NATALIA

Corrientes

Congreso; XXXI Reunion Argentina de Fisiología Vegetal; 2016

Sociedad Argentina de Fisiología Vegetal

Nitric oxide (NO) is a bioactive molecule that participates inmechanisms of hormone action associated to growth, development and stressprocesses in plants. Our laboratory has been pioneer in opening research fieldsto understand the role of NO in plant growth and development. NO inducesadventitious and lateral root formation as well as root hair elongation in bothdicots and monocots. NO is essential and required for the auxin signaltransduction pathway leading to root morphogenesis. The NO-mediatedposttranslational modification (PTM) of cysteines in proteins, calledS-nitrosylation, affects auxin perception and root development. The auxinreceptor TIR1 and ascorbate peroxidase 1 (APX1) are protein targets of PTM by NO.The regulation of S-nitrosylation/denitrosylation of APX1 modulates its enzyme activity,the normal lateral root development and auxin response. In animals, NO synthase(NOS) is the main enzyme that catalyses the synthesis of NO using L-Arg assubstrate. We found a canonical NOS enzyme in the marine green algae Ostreococcus tauri. The generation oftransgenic plants expressing OtNOS has allowed to manipulate NO levels inplants and improve not only the growing performance but also their tolerance toabiotic stresses.