Broad-range stress tolerance by the expression of the nitric oxide synthase from the unicellular marine algae ostreococcus tauri (Otnos) in Arabidopsis thaliana plants

MARTÍN MAYTA; NOELIA FORESI; ANABELLA LODEYRO; CLAUDIA CASSALONGUÉ; NÉSTOR CARRILLO; LORENZO LAMATTINA

Mar del Plata

Congreso; VIII Encuentro Latinoamericano y del Caribe de Biotecnología. Redbio; 2013

REDBIO

Nitric oxide (NO) is an important signalling molecule with diverse biological functions in plants. NO plays a crucial role in growth and development, from germination to senescence and it is also involved in the response to both abiotic and biotic stresses such as, drought, salinity, heat shock and plant diseases. There is also evidence supporting NO as a potent antioxidant protecting plants against oxidative damage. In animals, NO is synthesized through a nitric oxide synthase (NOS) enzyme.  Even though NOS activity has been detected in higher plants, no gene coding for a NOS protein has been identified so far. Recently, the NOS gene from the unicellular marine algae Ostreococcus tauri (OtNOS) has been characterized. In this work, Arabidopsis thaliana plants were transformed with OtNOS under the control of the PEC promoter of the sunflower gene, Hahb-4 which is inducible by water deficit, high salt concentrations and abscisic acid (ABA). Transgenic plants exhibited improved response to salt, drought and also oxidative stress tolerance. These findings reinforce the idea of NO as a mediator in stress responses and pave the way for the genetic manipulation of NO metabolism as a biotechnological tool for enhancing plant capabilities to cope with adverse environmental conditions.