Summary of Proposed Project:
This project will determine the function of the gene network required for exine synthesis, patterning and adhesion. This outer pollen wall is made of sporopollenin, an unusually strong, chemically inert, and distinctively patterned biopolymer. Exine protects desiccated pollen and binds to the stigma with strong and selective adhesives. Its importance in pollination, implications for polymer chemistry, and utility as a contact adhesive make an understanding of exine composition a high priority; nonetheless, its inert and irregular nature has confounded chemical analyses. Recent Arabidopsis genetic surveys are more promising, revealing genes and pathways required for exine structure and function. This project addresses the 2010 program goal of functional analysis of every Arabidopsis gene by screening mutant lines for exine phenotypes, assessing gene roles in exine assembly, patterning and adhesion, and sorting these genes into genetic and metabolic pathways. This work will impact multiple disciplines, improving the understanding of 1) genes that mediate pollination and crop breeding, 2) evolutionary controls over exine diversity and plant speciation, 3) exine moieties that form two-component adhesives, 4) phenolic and fatty acid metabolism, 5) biopolymer self-assembly, and 6) >250 genes in exine development, ~75% of which have not been targeted in other 2010 projects.

Broader Impacts of the Proposed Project:
This project will integrate research and education in several ways. First, the Preuss laboratory will host Drs. Edlund and Swanson and an undergraduate from each of their home institutions (Spelman and Valparaiso) for each summer of the proposal period. This will provide minority undergraduates with experience in planning and performing experiments and in presenting their work at undergraduate research conferences. Moreover, it will provide their mentors with information that they will incorporate into their laboratories and courses. Second, two undergraduates from the PI’s laboratory will collaborate with these visitors to perform phenotypic analyses and genetic screens. Over the past 10 years, the PI has trained 32 undergraduates (14 women and 7 underrepresented minorities). Third, this project will enable a postdoctoral associate to supervise technicians and undergraduate students, providing her with invaluable mentoring experience. Fourth, researchers from the PI’s laboratory will spend 6 months at the Noble Foundation, sharing their knowledge of pollination biology, and receiving training in plant biochemistry that will benefit their home institution. Lastly, the PI regularly participates in venues that introduce policy makers to plant genetic engineering, and in opportunities to teach and train business leaders in the challenges of translating research to the commercial sector.