Uracil salvage is necessary for early Arabidopsis development |
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Authors: | Samuel E Mainguet Bertrand Gakière Amel Majira Sandra Pelletier Françoise Bringel Florence Guérard Michel Caboche Richard Berthomé Jean Pierre Renou |
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Institution: | URGV, UMR INRA 1165 - CNRS 8114 - UEVE, 2, Rue Gaston Crémieux, CP5708, 91057 Evry cedex, France;, Institut de Biotechnologie des Plantes, Bat 630, UniversitéParis Sud XI, 91405 Orsay cedex, France;, Laboratoire de Biologie Cellulaire, INRA, Route de Saint-Cyr, 78026 Versailles cedex, France;, UMR7156 UniversitéLouis Pasteur/CNRS, Génétique Moléculaire, Génomique, Microbiologie, Département Microorganismes, Génomes, Environnement, 28 Rue Goethe, 67083 Strasbourg, France;, and Plateforme Métabolisme-Métabolome, IFR87, Bat 630, UniversitéParis Sud XI, 91405 Orsay cedex, France |
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Abstract: | Uridine nucleotides can be formed by energy-consuming de novo synthesis or by the energy-saving recycling of nucleobases resulting from nucleotide catabolism. Uracil phosphoribosyltransferases (UPRTs; EC 2.4.2.9) are involved in the salvage of pyrimidines by catalyzing the formation of uridine monophosphate (UMP) from uracil and phosphoribosylpyrophosphate. To date, UPRTs are described as non-essential, energy-saving enzymes. In the present work, the six genes annotated as UPRTs in the Arabidopsis genome are examined through phylogenetic and functional complementation approaches and the available T-DNA insertion mutants are characterized. We show that a single nuclear gene encoding a protein targeted to plastids, UPP , is responsible for almost all UPRT activity in Arabidopsis. The inability to salvage uracil caused a light-dependent dramatic pale-green to albino phenotype, dwarfism and the inability to produce viable progeny in loss-of-function mutants. Plastid biogenesis and starch accumulation were affected in all analysed tissues, with the exception of stomata. Therefore we propose that uracil salvage is of major importance for plant development. |
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Keywords: | Uracil phosphoribosyltransferase pyrimidine salvage Arabidopsis plastid early development |
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