Grant: Discovery Grants Program - Individual

Architectural diversity among plant species is a reflection of the key role that shape and form play in optimizing survival and reproductive success. An important goal of plant developmental biologists has been to identify genes that control plant architecture and to understand how these genes interact to generate structural diversity. Our focus is on BLADE-ON-PETIOLE1 (BOP1) and BOP2, a set of transcriptional co-regulators that control determinacy and boundary (junction) patterning in structures such as leaves, fruits, flowers, and the inflorescence. BOP proteins are related in sequence to the plant defense regulator NPR1, whose mode of action is well-studied and serves as a paradigm. Redox-dependent modification of NPR1 promotes its nuclear localization and interaction with TGACG-motif binding (TGA) bZIP transcription factors, necessary for activation of pathogen defense genes. The developmental roles of BOP1/2 and interacting TGA transcription factors are poorly understood. These roles will be studied in Arabidopsis thaliana, a simple model plant amenable to genetic, molecular, and biochemical approaches. Our work will build on progress made in the last five years and provide advanced training to students in a variety of specialized fields including genetics, biochemistry, molecular biology, and microscopy. Our current objectives are: 1) to further examine the role of BOP1/2-TGAs in termination of the floral meristem, 2) to identify additional roles for TGA factors in development, 3) to examine genetically how BOP1/2 contribute to meristem-organ boundary patterning in seedlings, 4) to examine the role of BOP1/2 in co-ordination of stem elongation and flowering, and 5) to further study the mechanism of BOP1/2 transcription factor activity. Our work will provide new insight into the molecular basis of plant architectural diversity and define potential redox-control mechanisms at play in development. Ultimately, this work will lead to new strategies for the directed manipulation of architectural traits to enhance the novelty and commercial valve of horticultural and ornamental crop species.