Patricia Springer
Associate Professor of Genetics
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Plant Biochemistry and Molecular Biology
Ph.D., Purdue University,W. Lafayette, IN, 1992
VOICE: 951-827-5785 |
The shoot apical meristem (SAM) is a population of cells that serves as the source of all of the above ground tissues of a plant. Very little is known about the molecular mechanisms controlling the function of this critically important structure. Research in my laboratory focuses on the molecular genetics of shoot apical meristem function, with emphasis on the role played by the SAM during the early events of leaf development. In order to identify components that are involved in SAM function, we have isolated genes that are specifically expressed in the SAM and/or surrounding cells. We use a transposable element that carries a GUS reporter gene (called a gene trap) to identify such genes.
We have isolated a number of genes that are expressed in specific domains in and around the SAM in Arabidopsis seedlings. Many of these genes are expressed in patterns that do not reflect tissue or cell type specificity, but instead appear to define previously unknown domains in the shoot apex. Interestingly, many of the genes we have identified are novel and appear to be plant-specific. We are characterizing these genes and defining their relationships with previously characterized genes that are important for SAM function. We have chosen to focus our attention on two genes, LATERAL ORGAN BOUNDARIES (LOB) and VASCULAR PREPATTERN (VPP). LOB is expressed at the base of all lateral organs, suggesting that it may play a role in establishing a boundary between the meristem and organ primordia. LOB encodes a protein that is does not contain any known domains and defines a gene family of 43 members in Arabidopsis. VPP is expressed in vascular precursor cells in young leaves. VPP is also novel and plant specific, and defines a family of 17 genes in Arabidopsis. Both LOB and VPP appear to be functionally redundant. We are using functional genomics tools to study the LOB-DOMAIN (LBD) and VPP-like (VPL) genes.
GUS reporter gene expression in transposant GT522. Expression (seen in blue) is in a group of cells subtending each leaf primordium.
SELECTED PUBLICATIONS
Shuai, B., C.G. Reynaga-Peņa, and P.S. Springer. 2002. The LATERAL ORGAN BOUNDARIES gene defines a novel, plant-specific gene family. Plant Physiol. 129: 747-761.
Holding, D.R. and P.S. Springer. 2002. The Vascular Prepattern enhancer trap marks early vascular development in Arabidopsis. Genesis 33: 155-159.
Baxter-Burell, A., Z. Yang, P.S. Springer, and J. Bailey-Serres. 2002. RopGAP4-dependent Rop GTPase rheostat control of Arabidopsis oxygen deprivation tolerance. Science 296: 2026-2028.
Holding, D.R. and P.S. Springer. 2002. The Arabidopsis gene PROLIFERA is required for proper cytokinesis during seed development. Planta 214: 373-382.
Springer, P.S., Holding, D.R., Groover, A., Yordan, C., and Martienssen, R.A. 2000. The essential Mcm7 protein PROLIFERA is localized to the nucleus of dividing cells during the G1 phase and is required maternally for early Arabidopsis development. Development 127: 1815-1822
Springer, P.S. 2000. Gene traps: tools for plant development and genomics. Plant Cell 12: 1007-1020.
SanMiguel, P., Tikhonov, A., Jin, Y.-K., Mogchoulskaia, N., Zakharov, D., Melake-Berhan, A., Springer, P.S., Edwards, K.J., Lee, M., Avramova, Z. and Bennetzen, J.L. 1996. Nested retrotransposons in the intergenic regions of the maize genome. Science 274: 765-768.
Springer, P.S., McCombie, W.R., Sundaresan, V. and Martienssen, R.A. 1995. Gene trap tagging of PROLIFERA, an essential MCM2-3-5-like gene in Arabidopsis. Science 268: 877-880.
Sundaresan, V., Springer, P., Volpe, T., Haward, S., Jones, J.D.G., Dean, C., Ma, H. and Martienssen, R. 1995. Patterns of gene action in plant development revealed by enhancer trap and gene trap transposable elements. Genes Dev. 9: 1797-1810.