Subcellular distribution of superoxide dismutase in leaves of ureide-producing leguminous plants |
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Authors: | Francisco J Corpas Luisa M Sandalio José M Palma Eduardo O Leidi José A Hernández Francisca Sevilla Luis A del Río |
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Institution: | Unidad de Bioquímica Vegetal, Estación Experimental del Zaidín, CSIC. Apdo, 419, E-18080 Granada, Spain;;Unidad de Alimentación y Desarrollo de la Planta, Centro de Edafología y Biología Aplicada del Segura, CSIC, Apdo. 195, E-30080 Murcia, Spain;. |
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Abstract: | The subcellular localization of superoxide dismutase (SOD; EC. 1.15.1.1) was studied in leaves of two ureide-producing leguminous plants ( Phaseolus vulgaris L. cv. Contender and Vigna unguiculata L.] Walp). In leaves of Vigna and Phaseolus , three superoxide dismutases were found, an Mn-SOD and two Cu, Zn-containing SODs (I and II). Chloroplasts, mitochondria, and peroxisomes were purified by differential and density-gradient centrifugation using either Percoll or sucrose gradients. The yields obtained in intact chloroplasts and peroxisomes from Vigna were considerably higher than those achieved for Phaseolus . Purified chloroplasts only contained the Cu, Zn-SOD II isozyme, but in mitochondria both Mn-SOD and Cu, Zn-SOD I isozymes were present. In purified peroxisomes no SOD activity was detected. The absence of SOD activity in leaf peroxisomes from Vigna contrasts with results reported for the amide-metabolizing legume Pisum sativum L. where the occurrence of Mn-SOD was demonstrated in leaf peroxisomes (del Río et al. 1983. Planta 158: 216–224; Sandalio et al. 1987. Plant Sci. 51: 1–8). This suggests that in leaf peroxisomes from Vigna plants the generation of O2- radicals under normal conditions probably does not take place. |
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Keywords: | Key words - Bean chloroplasts cowpea mitochondria peroxisomes Phaseolus vulgaris subcellular localization superoxide dismutase ureide metabolism Vigna unguiculata |
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