IIBBA   05544
INSTITUTO DE INVESTIGACIONES BIOQUIMICAS DE BUENOS AIRES
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Light regulates attachment, EPS production and nodulation in Rhizobium leguminosarum through LOV-histidine kinase photoreceptor
Autor/es:
BONOMI H.R.; POSADAS D.M.; PARIS G.; CARRICA M.C.; FREDERICKSON M.; PIETRASANTA L.I.; BOGOMOLNI R.; ZORREGUIETA A.; GOLDBAUM F.A.
Lugar:
Galvseton, Texas
Reunión:
Conferencia; Gordon Research Conference: Photosensory Receptors & Signal Transduction; 2012
Resumen:
Rhizobium leguminosarum is a soil bacterium that infects root hairs and induces the formation of nitrogen-fixing nodules on leguminous plants. LOV- (Light, Oxygen and Voltage) domain proteins are blue-light receptors found in higher plants and many algae, fungi, and bacteria. The genome of R. leguminosarum bv. viciae 3841, a pea-nodulating endosymbiont, encodes a sensor histidine kinase containing a LOV domain at the N-terminal end (R-LOV-HK). R-LOV-HK has a typical LOV domain absorption spectrum with broad bands in the blue and UV-A region and shows a truncated photocycle. Here we show that the R-LOV-HK protein regulates attachment to an abiotic surface, and production of flagellar proteins and exopolysaccharide in response to light. Also, illumination of bacterial cultures prior to inoculation of pea roots increases the number of effective nodules per plant and the number of intranodular bacteroids. The effects of light on nodulation were dependent on a functional lov gene. The results presented in this work suggest that light, sensed by R-LOV-HK, is an important environmental factor that controls the symbiotic efficiency of R. leguminosarum.