Les séminaires ont lieu sur le Campus Montpellier SupAgro/INRA de La Gaillarde (2, place P. Viala Montpellier)
Jeudi 20 octobre 2011
Amphi 208 (Cœur d’Ecole) à 14h
Pleiotropy and ecological laws: the same genes govern leaf functional trade-offs and plant allometry
Doctorant-Laboratoire d’Ecophysiology des Plantes sous Stress Environnementaux
Understand the genetic source of variation in resource-use strategy of plant is a challenging prospect for plant scientists and agronomists. In this perspective, recent studies argued for cross-disciplinary approaches, notably by using the advances in genetics and molecular biology of model species such as Arabidopsis thaliana for testing ecological and evolutionary theories. Among those, metabolic scaling theory (MST) and the leaf economics spectrum (LES) investigate the relationships between growth-related traits or leaf-level physiological trade-offs, respectively. Here we assessed the genetic determinisms of both theories in a segregating population of Arabidopsis thaliana. We show that (i) MST and LES are inextricably linked via two pleiotropic loci; and that (ii) the cross of genetic variants can generate within a generation a large fraction of the worldwide variation in LES traits; which then (iii) can generate much of the observed variation in the scaling functions described by MST. We validated two candidate genes, CRY2 which codes for a photoreceptor, and HUA2, a floral homeotic gene, as responsible for the phenotypes observed. Our results identify the genetic bases that unify MST and the LES within a species, and provide crucial insights into the understanding of the evolutionary processes at the origin of many botanical scaling relationships.
Contact : Christine Granier