title: In-silico analysis of water and carbon relations under stress conditions. A multi-scale perspective centered on fruit.
abstract: Fruit development, from its early stages, is the result of a complex network of interacting processes, on different scales. These include cell division, cell expansion but also nutrient transport from the plant, and exchanges with the environment. In the presence of nutrient limitation, in particular, the plant reacts as a whole, by modifying its architecture, metabolism, and reproductive strategy, determining the resources available for fruit development, which in turn affects the overall source-sink balance of the system. Here, we present an integrated model of tomato that explicitly accounts for early developmental changes (from cell division to harvest), and use it to investigate the impact of water deficit and carbon limitation on nutrient fluxes and fruit growth, in both dry and fresh mass. Variability in fruit response is analyzed on two different scales: among trusses at plant level, and within cell populations at fruit level. Results show that the effect of stress on individual cells strongly depends on their age, size, and uptake capabilities, and that the timing of stress application, together with the fruit position on the plant, is crucial in determining the final phenotypic outcome. Water deficit and carbon depletion impacted either source size, source activity, or sink strength with contrasted effects on fruit growth. An important prediction of the model is the major role of symplasmic transport of carbon in the early stage of fruit development, as a catalyst for cell and fruit growth.
authors.affiliation: Institut National de la Recherche Agronomique, UR 1115 Plantes et Systèmes de Culture Horticoles Avignon, France.
authors.forename: Valentina
authors.initials: V
authors.lastname: Baldazzi
authors.affiliation: Institut National de la Recherche Agronomique, UR 1115 Plantes et Systèmes de Culture Horticoles Avignon, France.
authors.forename: Amélie
authors.initials: A
authors.lastname: Pinet
authors.affiliation: Institut National de la Recherche Agronomique, UR 1115 Plantes et Systèmes de Culture Horticoles Avignon, France.
authors.forename: Gilles
authors.initials: G
authors.lastname: Vercambre
authors.affiliation: Institut National de la Recherche Agronomique, UR 1115 Plantes et Systèmes de Culture Horticoles Avignon, France ; Institut National de la Recherche Agronomique, UR 1332 Biologie du Fruit et Pathologie Villenave d'Ornon, France.
authors.forename: Camille
authors.initials: C
authors.lastname: Bénard
authors.affiliation: Institut National de la Recherche Agronomique, UR 1332 Biologie du Fruit et Pathologie Villenave d'Ornon, France.
authors.forename: Benoît
authors.initials: B
authors.lastname: Biais
authors.affiliation: Institut National de la Recherche Agronomique, UR 1115 Plantes et Systèmes de Culture Horticoles Avignon, France.
authors.forename: Michel
authors.initials: M
authors.lastname: Génard
keywords: cell division; cell expansion; development; model; plant architecture; stress; symplasm; tomato