IMPACT OF IRON AVAILABILITY ON TOMATO FRUIT QUALITY Esther Izquierdo Alegre1, Pierre Fourcroy1, Jossia Boucherez1, Geneviève Conéjéro1, Nicolas Tissot1, Christophe Rothan2, Cecile Bres2, Mathilde Causse3, Patricia Sisó-Terraza4, Ana Álvarez-Ferández4, Javier Abadía4, Jean-François Briat1, Frédéric Gaymard1, Christian Dubos1, * 1: Biochimie et Physiologie Moléculaire des Plantes, INRA, CNRS, Université Montpellier, SupAgro, Bat 7, 2 place Viala, 34060, Montpellier Cedex 1, France 2: INRA, University of Bordeaux, Unité Mixte de Recherche 1332, Fruit Biology and Pathology, 33140 Villenave d’Ornon, France 3: INRA, UR1052, Génétique et Amélioration des Fruits et Légumes, 67 Allée des chênes, Centre de Recherche PACA, Domaine Saint Maurice, CS60094, 84143 Montfavet, France 4: Department of Plant Nutrition, Estacióon Experimental de Aula Dei (CSIC), Av. Montan~ana 1005, E-50080, Zaragoza, Spain *[email protected] Tomato (Solanum lycopersicum) is one of the most important vegetables in the world. Since 50 years tomato breeding has focused on improving yield, disease resistance and traits in relation with fruit appearance and shelf life. Improving fruit organoleptic quality is also the focus of intensive research centred around three main axes: flavour, aroma, and texture. We have recently initiated a research program aiming at studying the impact of iron (Fe) availability on fruit quality focusing on both fruit maturation and micronutrient content (especially Fe). For this purpose two main strategies are being developed. The first one relies on the functional characterization of tomato ortholog genes involved in Fe assimilation, with a special interest on the PDR9/ABCG37 transporter. In Arabidopsis thaliana, PDR9/ABCG37 is involved in the secretion of phenolic compounds into the media in response to Fe shortage in order to facilitate Fe(III) reduction by the FRO2 reductase (the generated Fe 2+ being subsequently transported across epidermal cells through IRT1). The second strategy relies on the use of genetic approaches in order to identify genes and/or polymorphisms that control Fe (and other micronutrients) content in fruits. Our main findings will be discussed. Keywords: Iron, PDR9, Fruits, Tomato