Expression and localization of a Rhizobium-derived cambialistic superoxide dismutase in pea (Pisum sativum) nodules subjected to oxidative stress

Two phylogenetically unrelated superoxide dismutase (SOD) families, i.e., CuZnSOD (copper and zinc SOD) and FeMn- CamSOD (iron, manganese, or cambialistic SOD), eliminate superoxide radicals in different locations within the plant cell. CuZnSOD are located within the cytosol and plastids, while the second family of SOD, which are considered to be of bacterial origin, are usually located within organelles, such as mitochondria. We have used the reactive oxygen species-producer methylviologen (MV) to study SOD isozymes in the indeterminate nodules on pea (Pisum sativum). MV caused severe effects on nodule physiology and structure and also resulted in an increase in SOD activity. Purification and N-terminal analysis identified CamSOD from the Rhizobium leguminosarum endosymbiont as one of the most active SOD in response to the oxidative stress. Fractionation of cell extracts and immunogold labeling confirmed that the CamSOD was present in both the bacteroids and the cytosol (including the nuclei, plastids, and mitochondria) of the N-fixing cells, and also within the uninfected cortical and interstitial cells. These findings, together with previous reports of the occurrence of FeSOD in determinate nodules, indicate that FeMnCamSOD have specific functions in legumes, some of which may be related to signaling between plant and bacterial symbionts, but the occurrence of one or more particular isozymes depends upon the nodule type. © 2011 The American Phytopathological Society.Peer Reviewe

Identification and characterization of a camialistic superoxide dismutase fron bacteroids in the cytosol of pea nodules

Trabajo presentado en la XIII National Meeting of the Spanish Society of Nitrogen Fixation (SEFIN) y el II Portuguese-Spanish Congress on Nitrogen Fixation, celebrados en Zaragoza del 15 al 18 de junio de 2010.Peer Reviewe

Protein malnutrition during juvenile age increases ileal and colonic permeability in rats

Protein malnutrition can lead to morphological and functional changes in jejunum and ileum, affecting permeability to luminal contents. Regarding the large intestine, data are scarce, especially at juvenile age. We investigated whether low-protein (LP) diet could modify ileal and colonic permeability and epithelial morphology in young rats. Isocaloric diets containing 26% (control diet) or 4% protein were given to male rats between postnatal days 40 and 60. LP-diet animals failed to gain weight and displayed decreased plasma zinc levels (a marker of micronutrient deficiency). In addition, transepithelial electrical resistance and occludin expression were reduced in their ileum and colon, indicating increased gut permeability. Macromolecule transit was not modified. Finally, LP diet induced shortening of colonic crypts without affecting muscle thickness. These data show that protein malnutrition increases not only ileum but also colon permeability in juvenile rats. Enhanced exposure to colonic luminal entities may be an additional component in the pathophysiology of protein malnutrition.Fondecyt 1130213 PUCV-DI 037.470/201

Sistema flexible de control de una red de sensores por fibra óptica para un edificio inteligente

At the present, optical fibre is the more and more used in the intelligent buildings networks. Actually, most of the backbone networks and even horizontal cabling in this kind of buildings use optical fibre for data transmission. This is because it is possible to hybridize this data networks with others, like sensors networks, CATV networks, etc. getting to an upper degree of service integration. In this work, a flexible system is presented to control an intelligent building fiber optic based sensor network