Seasonal control of flowering
433 Babcock Dr
Madison, WI 53706
Plant Biology; Developmental Biology & Regenerative Medicine
The major developmental change in the plant life cycle is the initiation of flowering. Many plant species have evolved the ability to regulate flowering in response to environmental variables such as changes in day-length or temperature. We have been studying how, at a molecular level, plants sense and respond to environmental cues We begin with genetic analysis to identify genes involved in environmental sensing as it relates to flowering, and gene identification provides an entre for us to explore the biochemistry of this process. We have made much progress in understanding in Arabidopsis thaliana. For example, we discovered a gene (FLC) that prevents flowering in Arabidopsis unless the plants have experienced the cold of winter. Exposure to cold (through a process known as vernalization) promotes flowering by a stable epigenetic switch of FLC to a repressed state. This epigenetic state of FLC is reset to an active state in the next generation. Recently, we have shifted to studying the molecular basis of flowering in the model grass Brachypodium distachyon. Much of the environmental flowering responses in grasses evolved independently of those in Arabidopsis (for example, it was only after the divergence of these lineages that continents drifted and climate changed such that a vernalization response was adaptive). In the past four years we have done extensive genetic screens to identify flowering mutants and using map-based cloning have identified twelve novel genes that are involved in flowering control in response to seasonal and developmental cues (these genes that are not involved in flowering in Arabidopsis). We are now using this foundation to understanding the molecular pathways that regulate flowering in grasses. Two of the reasons I shifted to work on grasses are 1) I have encouraged lab members to take key Arabidopsis flowering projects with them to faculty positions and many are doing well with these projects at good institutions like Cornell, University of Texas at Austin, Indiana University, Michigan State, and Seoul National, and 2) grasses are an important group of plants in many ecosystems and in agriculture (rice, wheat, corn, sorghum, etc. are grasses).