title: Genotype-dependent response to carbon availability in growing tomato fruit.
abstract: Tomato fruit growth and composition depend on both genotype and environment. This paper aims at studying how fruit phenotypic responses to changes in carbon availability can be influenced by genotype, and at identifying genotype-dependent and -independent changes in gene expression underlying variations in fruit growth and composition. We grew a parental line (Solanum lycopersicum) and an introgression line from Solanum chmielewskii harbouring quantitative trait loci for fresh weight and sugar content under two fruit loads (FL). Lowering FL increased fruit cell number and reduced fruit developmental period in both genotypes. In contrast, fruit cell size was increased only in the parental line. Modifications in gene expression were monitored using microarrays and RT-qPCR for a subset of genes. FL changes induced more deployments of regulation systems (transcriptional and post-transcriptional) than massive adjustments of whole primary metabolism. Interactions between genotype and FL occurred on 99 genes mainly linked to hormonal and stress responses, and on gene expression kinetics. Links between gene expression and fruit phenotype were found for aquaporin expression levels and fruit water content, and invertase expression levels and sugar content. In summary, the present data emphasized age- and genotype-dependent responses of tomato fruit to carbon availability, at phenotypic as well as gene expression level.
authors.affiliation: INRA, UR1115 Plantes et Systèmes de culture Horticoles, F-84000 Avignon, France. marion.prudent@dijon.inra.fr
authors.forename: Marion
authors.initials: M
authors.lastname: Prudent
authors.forename: Nadia
authors.initials: N
authors.lastname: Bertin
authors.forename: Michel
authors.initials: M
authors.lastname: Génard
authors.forename: Stéphane
authors.initials: S
authors.lastname: Muños
authors.forename: Sophie
authors.initials: S
authors.lastname: Rolland
authors.forename: Virginie
authors.initials: V
authors.lastname: Garcia
authors.forename: Johann
authors.initials: J
authors.lastname: Petit
authors.forename: Pierre
authors.initials: P
authors.lastname: Baldet
authors.forename: Christophe
authors.initials: C
authors.lastname: Rothan
authors.forename: Mathilde
authors.initials: M
authors.lastname: Causse
mesh_terms: D002244:Carbon / Q000378:metabolism*; D005638:Fruit / Q000235:genetics / Q000254:growth & development*; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D005838:Genotype; D018551:Solanum lycopersicum / Q000235:genetics* / Q000254:growth & development; D020411:Oligonucleotide Array Sequence Analysis; D010641:Phenotype; D040641:Quantitative Trait Loci; D018749:RNA, Plant / Q000235:genetics
chemical_list: D018749:RNA, Plant; D002244:Carbon