Résumé
Background / Purpose:Pleiotropic genes have been identified to control simultaneously many processes involved in key functions like growth and reproduction. Mutations in these central genes affect numerous traits, but their impact on response to selection in natural populations, in which the genetic background and environments vary, remains poorly understood. We developed a modeling approach to uncover the variation of a critical trait related to fitness, the vegetative rosette surface development of Arabidopsis thaliana, at different levels of organization and for different processes such as flowering, cellular proliferation and expansion.Main conclusion:Plant growth, phenology and leaf anatomy were analyzed under well-watered and water-deficient conditions. In the joint population, ERECTA gene had common effects on cell patterning. However, differential trade-off effects of ERECTA on whole rosette development were found in each population induced by genotype-dependent epistatic interactions, revealing cryptic genetic variations at different levels. In response to water deficit, ERECTA affected the coordinated response of rosette development, through interaction with the quantitative trait loci (QTL), depending on the population in which the mutation segregates