Spatio-temporal regulation of hormonal interactions in Arabidopsis shoot apex: Live imaging and cell type-specific analysis

University Of California-Riverside, Riverside CA

Investigators

Abstract

The arrangement of leaves along a plant shoot or branch is determined by the manner in which undifferentiated cells in shoot apical meristems (SAMs) cells are allocated to leaf primordia. The arrangement is critical because it determines the plant's light harvesting capability, which in turn influences biomass production. This project aims to understand dynamic processes that control the spatial patterning of leaf development in the model plant Arabidopsis thaliana. The plant hormones auxin and cytokinin play crucial roles, but while computational models explain the importance of auxin, the function of cytokinin is not well understood. This is because cytokinin regulates several interconnected processes that cannot be easily deciphered by traditional static analytical methods. This project will elucidate the role of cytokinin using transient manipulation of hormone levels and signaling followed by live imaging and high-resolution molecular analysis. It will also explore how auxin and cytokinin influence locally-acting transcription factors implicated in leaf patterning. The project outcomes will be used to develop predictive computational models to facilitate engineering of crop plants for optimal light harvest and increased productivity. The live images of actively developing shoot apices of plants and dynamic data sets will be used in a new interdisciplinary graduate course on developmental dynamics, and in an undergraduate cell biology course. These data also will be incorporated into a summer workshop for schoolteachers that will introduce them to recent progress in dynamic analysis of developmental systems. The dynamic data sets will be made available through a web portal (http://cybersam.ucr.edu/Plone) for use in research and teaching. The project will also provide training in live imaging, image processing and high-resolution genomics for a postdoctoral fellow, a graduate student and several undergraduates.