This NSF 2010 project will examine the function of a family of genes that encodes a novel, plant-specific protein domain, the LOB domain. In Arabidopsis, 43 LBD genes encode proteins that contain a LOB domain, a conserved domain of approximately 100 amino acids that does not contain any recognizable sequence motifs. Proteins containing LOB-domains are not found outside of plants, making this gene family one of about 150 plant-specific gene families in Arabidopsis. The only LBD gene with a defined genetic function, ASYMMETRIC LEAVES2 (AS2), regulates adaxial-abaxial polarity in lateral organs and is required for repression of the KNOX class of transcription factors. The functions of other LBD genes are not known. Information on the status of the project will be maintained at a public database (http://faculty.ucr.edu/~pspringe). Functional characterization of LBD genes will be accomplished by determining the mRNA expression patterns of each gene, and by generating transgenic plants that have increased or decreased activity of select family members. Clones and transgenic plants that are generated as a result of this research will be freely distributed through the Arabidopsis Biological Resource Center (ABRC). Research results will be presented at scientific meetings and published in scientific journals in a timely fashion. Functional characterization of LBD genes, which encode proteins of unknown function, fits the goal of the 2010 program to determine the function of all Arabidopsis genes, especially those genes whose function can't be predicted by homology. In addition, understanding the function of plant-specific genes like the LBD genes will likely yield important information about processes that are unique to plants. This project also establishes an international collaboration with the University of Duesseldorf.
Broader Impacts: An important component of the project is the development of teaching resources utilizing the LBD genes. Undergraduate students in courses at UMass Boston and UC Riverside will undertake hypothesis-driven research on the LBD genes, and will have access to project data and mutant and transgenic plants for their research. In addition, a workshop focused on incorporation of plant molecular genetics into the high school curriculum will be developed for high school teachers in the Boston public school district and in the Riverside and San Bernardino public school districts. Modules for teaching at the high school, community college, and four-year college will be developed using the LBD genes as illustrative models.
