Localisation of β-oxidation enzymes in peroxisomes of rice coleoptiles |
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Authors: | Laura Pistelli Nicoletta Rascio Luigi De Bellis Amedeo Alpi |
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Institution: | Dipartimento di Biologia delle Piante Agrarie, Univ. di Pisa, viale delle Piagge 23, I–56124 Pisa;Univ. di Padova, Dipartimento di Biologia, via Orto Botanico, I–35100 Padova, Italy. |
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Abstract: | Enzymes of the β-oxidation pathway in rice ( Oryza sativa L., cv. Arborio) coleoptiles were investigated. The coleoptiles contain acyl-CoA oxidase (EC 1.3.99.3), 3-hydroxyacyl-CoA dehydrogenase (EC 1.1.1.35), enoyl-CoA hydratase (EC 4.2.1.17) and thiolase (EC 2.3.1.9). Analysis of coleoptile homogenates by sucrose density fractionation showed a preferential distribution of these enzymes in the unspecialized peroxisomes. The enzymatic activity found in the mitochondrial fraction was due to peroxisomal contamination since electron micrographs show the peroxisomes to be intact and pure whereas the mitochondrial fraction was contaminated by other organelles. It appears that the β-oxidation pathway is localized in the unspecialized peroxisomes of rice coleoptiles, extending the number of plant species in which such a localization has been observed. |
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Keywords: | Coleoptile electron microscopy mitochondria Oryza sativa β-oxidation peroxisomes rice |
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