XVI International Botanical Congess

While phenotypic plasticity has been studied from an ecological and genetic standpoints, little is known about its evolution at the organismal (changes among related species) or molecular (environmental receptors and transduction pathways) levels. The model plant Arabidopsis thaliana offers a rare opportunity to address both problems from an integrated perspective. I discuss how phylogenetically informed studies of different types of plasticities in A. thaliana are been guided by our knowledge of the molecular evolution of the underlying mechanisms. Plasticities to nutrient availability evolve less rapidly than the corresponding character means, and genetic similarity among ecotypes is not a good predictor of similarity in reaction norms. Plasticities to photoperiod and shade avoidance may have constrained each other during the evolution of A. thaliana and related species.