9507218 Meeks-Wagner The long term goal of this research is to understand the molecular mechanisms that regulate the initiation of flowering in response to changes in daylength. As a first step toward reaching this goal, the photoperiod-sensitive genetic pathway(s) controlling inflorescence initiation and development in Arabidopsis thaliana will be investigated. A mutation, Early Flowering 3 , (ELF3) has been isolated and results suggest that it may function as a key component of circadian rhythm regulation, as well as a regulator of inflorescence and floral meristem identity . We will: 1. Define the role of ELF3 gene in the circadian regulation of gene expression and developmental processes. 2. Isolate a molecular clone of ELF 3 and complete the basic characterization of the gene. 3. Define the genetic pathways related to ELF3 gene function that regulate floral initiation and floral meristem identity in Arabidopsis. %%% The research to be done is directed toward testing the hypothesis that the ELF 3 gene product plays a critical role in regulating photoperiodism by "linking" the biological clock (s) to the genetic pathways that control floral initiation and flower meristem development. The gene will be cloned and characterized and the function of its product studied. Completion of these aims should provide valuable information on the genetic regulation of circadian responses and the photoperiodic induction of flowering. The results will enhance our basic knowledge as well l as provide information which could have possible economic ramifications. ***
