Life History Variation and Biomass Allocation

Plants integrate a spectacular amount of environmental data on time scales bridging minutes (e.g. passing clouds can alter available light) to seasons (temperature and water availability) to decades (climate trends, including anthropogenic change). A plant’s life history – its lifespan and when and how often it reproduces -- dictates the extent to which it must respond to cues at these different temporal scales. Life history variation represents compromises between biomass allocation, survivorship risks, and subsequent fitness benefits.

The Des Marais Lab has developed the grass genus Brachypodium as a model system for studying the impact of temporal environmental heterogeneity on the evolution of life history strategies (Des Marais & Juenger 2016). These issues are not merely academic – plant strategies for carbon and nutrient allocation to biomass vs. reproduction are central to agricultural output. We are working with the US DOE Joint Genome Institute to develop genomic resources to study the physiological and developmental control of annual vs perennial life history strategies in Brachypodium. Current projects include understanding genetic correlations among developmental and ecophysioligcal traits in perennial and annual species, identifying the molecular control of seasonal changes in growth and resource allocation, and determining the environmental context of perennial and annual species using niche modeling.