This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).
The unique ability of plants to initiate organs throughout their lifespan results from the activity of meristems. The shoot apical meristem, a group of cells at the apex of the plant, provides cells for the initiation of lateral organs such as leaves and flowers while maintaining a central core of stem cells that remain undifferentiated. The shoot apical meristem is highly organized and yet dynamic, responding to local signals and those originating from more distant parts of the plant. Gradients of plant hormones within the meristem appear to be important in balancing stem cell renewal with organ initiation. But it is not clear how these hormone gradients are generated and how they are translated into different cellular behaviors. This project will investigate the hormonal regulation of shoot apical meristem function in the model plant Arabidopsis thaliana. The role of three related AINTEGUMENTA-like (AIL) proteins in mediating the antagonistic behavior of two plant hormones (auxin and cytokinin) within the meristem will be investigated by genetic, molecular and live imaging approaches. The expected results from this work are an integration of these AIL genes into a genetic framework for meristem function, molecular information on how these proteins regulate hormone levels/responsiveness, and a spatiotemporal map of the dynamic interactions between the expression of these proteins and hormone gradients within the meristem. Because the shoot apical meristem shapes the overall architecture of plants, this work has broad implication for the design of food and biofuel crops with improved yields and the production of new varieties of ornamental plants. The project will provide training opportunities for students, a postdoctoral fellow and a K-12 teacher.
