Genetic and Genomic Approaches to Understanding the Role of Auxin in Shoot Development

  • McSteen, Paula (PI)
  • Malcomber, Simon (CoPI)
  • Zhao, Yunde Y. (CoPI)
  • Brusslan, Judith J.A. (CoPI)
  • Gallavotti, Andrea (CoPI)
  • Altman, Naomi N.S. (CoPI)

Project Details


PI: Paula McSteen (University of Missouri - Columbia)

CoPIs: Simon Malcomber (California State University - Long Beach), Andrea Gallavotti and Yunde Zhao (University of California - San Diego)

Senior Personnel: Naomi Altman and Reka Albert (The Pennsylvania State University)

Collaborator: Robert Schmidt (University of California - San Diego)

The hormone auxin regulates almost every aspect of plant growth and development, including leaf and flower formation, and stem and flower cluster (inflorescence) branching. The long-term goal of this project is to understand how shoot (the above ground portion of a plant) growth is regulated through pathways of auxin biosynthesis, transport and signal transduction, and the extent to which these mechanisms and interactions are conserved among the approximately 250,000 described species of flowering plants. Genes that function in auxin mediated shoot development will be identified and characterized using a combination of high throughput forward genetics in maize and comparative expression profiling in both maize and Arabidopsis. Reverse genetic analyses will be used to uncover the function of genes in these pathways that may not be apparent from forward genetic approaches alone. Gene function will be analyzed using transgenic reporter lines coupled with phenotypic, expression and genetic analyses of characterized mutants to assemble a network of genetic interactions. A gene regulatory network model will be built to integrate the data from expression profiling together with genetic and biochemical interaction studies. Phylogenetic characterization of identified gene families using available genomic data and genes isolated during the course of the research will provide a framework and series of testable hypotheses concerning the conservation and diversification of auxin mechanisms in all flowering plants. The findings from this project will lead to a better understanding of how auxin controls shoot growth and development in agronomically and economically important crops.

Through a series of training and outreach programs this project will provide opportunities for high school students, undergraduates, graduate students, and postdoctoral researchers to learn and apply a broad range of genetic, developmental, evolutionary, genomic, statistical, mathematical and bioinformatic tools. Annual summer workshops and exchange programs will augment inter-disciplinary plant science training and dialog across fields. Results from the project will be incorporated into the Botanical Society of America's Planting Science program ( to create online open-ended, inquiry-based educational materials focusing on the role of auxin and the interdisciplinary nature of plant biology for high school students across the nation. Materials from this project will provide new resources and tools to investigate the role played by auxin in plant growth and development across flowering plants, and new information and strategies for improving crop yield in diverse crop species.

Project data will be made available through the project website ( In addition, mutant stocks will be available from the Maize Coop Stock Center (, phenotypic and genetic data including map locations will be deposited at MaizeGDB (, expression profiling data will be deposited at the Plant Expression Database (, phylogenetic trees will be deposited at TREEBASE ( and sequences will be deposited in Genbank( and Plant GDB (

Effective start/end date7/1/106/30/16


  • National Science Foundation: $3,942,508.00


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