INSTITUTO DE FISIOLOGIA VEGETAL
Unidad Ejecutora - UE
congresos y reuniones científicas
Linking nitric oxide synthesis and chloroplasts functionality.
GALATRO A; PUNTARULO S; GUIAMET JJ; SIMONTACCHI M
Congreso; VIII International Congress Society for Free Radical Biology and Medicine South American Group; 2013
Society for Free Radical Biology and Medicine, South American Group
Nitric oxide (NO) as an endogenous product in plants participates in a wide spectrum of biologically important reactions, being a component in responses to biotic and abiotic stress and a mediator in hormone-regulated processes. However, the sources of NO, which probably rely on local substrates availability such as L-arg, O2, or nitrite concentrations, as well as changes in pH, remain unclear. We explore the hypothesis that the content of NO in soybean cotyledons is related to chloroplast functionality in planta. Employing fluorescence microscopy and electron paramagnetic resonance (EPR) we found that chloroplasts contribute to NO synthesis in vivo. Chloroplast functionality was assessed measuring photosystem II quantum yield (PSII). A parallelism was found between total NO content in tissue, the detection in chloroplasts and PSII along the cotyledon life span and in conditions that severely affect photosynthetic electron transport. These findings suggest that chloroplasts are organelles that contribute to NO synthesis in vivo, and that their proper functionality is essential for maintaining NO levels in soybean cotyledons.