Understanding the evolution of the alternation of generations in the land plant life cycle

Land plants have a unique life cycle. Like animals, some of their life is spent as a diploid that undergoes meiosis to generate haploid spores. But, unlike animals, these spores grow into multi-cellular structures before generating gametes. Thus their single genome is responsible for generating two body plans. The aim of this proposal is to deduce the genetic and evolutionary basis of this dimorphic life cycle. We will focus on the role of a plant-specific gene family that encodes homeo-domain proteins. Their function will be deduced in the model flowering plant Arabidopsis, likely to have evolved derived functions, and compared with that in a liverwort, a basal land plant that may well retain characters of the ancestral land plant.