Nitrogen oxidized species (RNS) are molecules involved in cell signalling, characterized for modulating plant responses to stressful conditions. An essential RNS in plants is nitric oxide (NO), known for mediating in numerous physiological processes. Despite the importance of NO for plant development, the existence of a mammalian-like nitric oxide synthase is doubtful and data on oxidative production of NO in plants are still vague (1). However, the detection of NO, nitrite and nitrate in plants grown under exclusive ammonium nutrition demonstrates the existence of oxidative reactions leading to the production of such molecules from the ammonium cation. It has been described that phosphorous deficiency enhances NO production (2) and that the enzymatic system cytochrome P450 (CytP450) is induced by phosphorous starvation (3). For that reason, the general aim of this work was to study the effect of the herbicide ioxynil, a CytP450 inhibitor, and phosphorus deficiency, which induces CytP450, monitoring NO and nitrate production in pea plants under ammonium nutrition. Phosphorous deficiency enhanced lateral root development and decreased growth, whilst ioxynil inhibited lateral root growth. The implication of CytP450 in nitrogen oxidation is discussed. The study of NO production under ammonium nutrition will have a clear impact in the knowledge of tolerance to ammonium in plants of agricultural interest, and it will surely contribute to ameliorate fertilization policies.

Póster presentado en el Plant Biology Europe 2014 Congress (FESPB/EPSO) celebrado en Dublín (Irlanda), del 22 al 26 de junio de 2014

Peer Reviewed