Assistant Professor of Biology
B.S.: 1990 University of Utah, Cell and Neurobiology
Ph.D.: 1999 Purdue University, Plant Cell Biology and Genetics
Postdoc: University of Arizona, Dept. of Plant Sciences
I am interested in the cell and molecular biology of maize endosperm development. In particular, I study the deposition of storage proteins in the endosperm and how these proteins influence kernel texture in the mature seed. The most abundant maize storage proteins, prolamin proteins called zeins, are deposited in the endoplasmic reticulum in specialized structures called protein bodies. The zein proteins lack lysine and tryptophan, two essential amino acids for monogastric animals, and thus reduce the nutritional quality of maize as food.
I have been studying maize mutant lines that reduce the abundance of zeins and improve the protein quality. There are two main projects in my lab. The first is to characterize the biochemical and physical changes of starch in Quality Protein Maize lines to determine if these changes alter the association of the starch with cellular proteins. The other project is to study the specialized regions of endoplasmic reticulum where protein bodies form during endosperm development.Caption for photo: Image of an F2 ear segregating for modified, hard Quality Protein Maize kernels (dark and transluscent) and soft, starchy opaque kernels (light colored and floury).
Gibbon, B. C., Tikhonov, A., Crasta, O., Fallis, L., Jung, R., and Larkins, B. A. Proteomic and Transcriptional profiling of the opaque2 mutant reveals several new targets of Opaque2 regulation. In preparation.
Kim, C. S., Gibbon, B. C., Gillikin, J. W., Wrobel, R. L., Larkins, B. A., Boston, R. S. and Jung, R. (2006) The Maize Mucronate Mutation is a Deletion in the 16-kD _-Zein Gene that Induces the Unfolded Protein Response. Plant J. 48, 440-451.
Kirst, M. E., Meyer, D. J., Gibbon, B. C., Jung, R., Boston, R. S. (2005) Identification and Characterization of ER-Associated Degradation Proteins Differentially Affected by ER Stress. Plant Physiol. 138, 218-231.
Gibbon, B. C. and Larkins, B. A. (2005) Molecular genetic approaches to developing Quality-Protein Maize. Trends Genet. 21, 227-233.
Lopez-Valenzuela, J. A., Gibbon, B. C., Holding, D. R., and Larkins, B. A. (2004) Cytoskeletal proteins are coordinately increased in maize genotypes with high levels of eEF1A. Plant Physiol. 135, 1784-1797.
Gibbon, B. C., Wang, X., Larkins, B. A. (2003) Altered starch structure is associated with endosperm modification in quality-protein maize. Proc. Natl. Acad. Sci. USA. 100, 15329-15334.
Lopez-Valenzuela, J. A., Gibbon, B. C., Hughes, P. A., Dreher, T. W., and Larkins, B. A. (2003) eEF1A isoforms change in abundance and actin-binding activity during maize endosperm development. Plant Physiol. 133, 1285-1295.