INSTITUTO DE FISIOLOGIA VEGETAL
Unidad Ejecutora - UE
congresos y reuniones científicas
Nitric oxide synthesis in soybean Plants
GALATRO A; PUNTARULO S; SIMONTACCHI M
Workshop; Workshop on Adaptation to climate change in Central and South American key sectors. In the week of the Third Lead Author Meeting of the IPCC WGII.; 2012
Programa Interdisciplinario de la UBA sobre el Cambio Climático (PIUBACC)
Nitrogen oxides (NOX) have important roles in the atmosphere chemistry. NOX are mainly derived from fossil fuel combustion, soil-biogenic emissions, biomass burning, and lightning. Nitric oxide (NO) and nitrous oxide (N2O) are known as intermediate products of nitrification and denitrification processes in soils. N2O is a greenhouse gas with 296 times larger global warming potential than carbon dioxide. It is well known that environmental problems, such as photochemical smog formation, acid rain, greenhouse effect, etc., are related to gaseous nitrogen oxides. Soils, as the major reaction sites of nitrogen cycling, have been recognized as an important source of atmospheric nitrogen oxides. Besides the soil, NO emitted by plants could be considered as another important source of nitrogen oxides. Nitric oxide plays important roles in plants, where it is involved in physiological processes and plant responses to biotic and abiotic stresses. Exchange of NO between the atmosphere and aerial plant organs as well as between rhizosphere and roots occurs. Although NO is a key signaling molecule acting throughout the lifespan of plants, how plants or tissues regulate NO levels remains unclear, being currently a subject of study. It is clear that NO content in plants varies among tissues, depends on physiological status and also occurs as a generalized stress response. This study explores the hypothesis that the content of NO in soybean cotyledons is related to chloroplast functionality in planta. Employing fluorescence microscopy and electronic paramagnetic resonance (EPR) we showed that chloroplasts contribute to NO synthesis in vivo. Moreover, the level of NO in the whole tissue is related to chloroplast functionality. The knowledge of the sources of NO generation in plants and the factors that may affect it, are essential to support the studies of NO emissions from crop lands, and are important when developing strategies designated to mitigate nitrogen emissions and to improve growth response to different environmental stresses. This study was supported by grants from the Agencia Nacional de Promoción Científica y Tecnológica (ANPCyT), UBACyT (UBA) and CONICET.