John C. Sedbrook

Associate Professor of Genetics

Coordinator, Energy Science Program

Participant, Great Lakes Bioenergy Research Center (GLBRC)

Postdoctoral Research: Carnegie Institution, Stanford University, Stanford, CA

Research Interests

Molecular genetics of cell expansion and tropic responses in Arabidopsis thaliana.

Improvement of plant biomass for use as feedstocks to generate biofuels.

Research Description

Molecular genetics of directional cell expansion and cell wall formation

Plants position their organs within the soil and above ground by tightly regulatiing directional cell expansion in response to a number of environmental stimuli including touch, gravity, and light. We have identified a number of root cell expansion mutants affected in touch and/or gravity responsiveness by employing the so-called root waving assay on mutant populations of the model dicot Arabidopsis thaliana. This work has revealed that microtubule associated proteins (MAPs) play a central role in the underlying growth processes. In particular, we have uncovered a number of MAPs that bind to the growing ends of cortical microtubules (so-called +Tip Interacting Proteins or +TIPs) where they likely regulate microtubule polymerization dynamics and cell signaling events. Our ongoing work is aimed at elucidating how these proteins work together to regulate important cell expansion processes and cell wall formation.

Plant biomass feedstock improvement

As part of the DOE funded Great Lakes Bioenergy Research Center (GLBRC), we are working with teams of researchers in an effort to improve the quality of plant biomass for use as biofuels feedstocks. One such project being carried out in our laboratory employs the model grass Brachypodium distachyon to identify genes affecting the enzymatic digestion and subsequent fermentation of sugars released from cell wall polymers such as cellulose and hemicellulose. Our long term goal is to use this knowlede to genetically improve biomass quality and quantity of bioenergy crop grasses such as switchgrass and Miscanthus.

Representative Publications

Sedbrook, J. C. and Kaloriti, D. (2008) Microtubules, MAPs and plant directional cell expansion. Trends Plant Sci 13:303-10.

Kirik, V, Herrmann, U, Parapalli, C, Sedbrook, J.C., Ehrhardt, D.W., and Hülskamp, M. (2007) CLASP localizes in two discreet patterns on cortical microtubules and is required for cell morphogenesis and cell division in Arabidopsis. J. Cell Sci. 120:4416-25.

Kaloriti, D., Galva, C., Parupalli, C., Khalifa, N., Galvin, M., and Sedbrook, J. C. (2007) Microtubule Associated Proteins in plants and the processes they manage. J Integr Plant Biol 49:1164-1173.

Yuen, C. Y., Sedbrook, J. C., Perrin, R. M., Carroll, K. L., and Masson, P. H. (2005). Loss-of-function mutations of ROOT HAIR DEFECTIVE3 suppress root waving, skewing, and epidermal cell file rotation in Arabidopsis. Plant Physiol. 138: 701-714.

Gillmor, C. S., Lukowitz, W., Brininstool, G., Sedbrook, J. C., Hamann, T., Poindexter, P., and Somerville, C. (2005). Glycosylphosphatidylinositol-anchored proteins are required for cell wall synthesis and morphogenesis in Arabidopsis. Plant Cell. 2005 17: 1128-1140.

Sedbrook, J. C. (2004). MAPs in plant cells: delineating microtubule growth dynamics and organization. Cur. Opin. Plant Biol. 7: 632-640.

Sedbrook, J. C., Ehrhardt, D. W., Fisher, S. E., Scheible, W.-R., and Somerville, C. R. (2004). The Arabidopsis SKU6/SPR1 gene encodes a plus-end localized microtubule-interacting protein involved in directional cell expansion. Plant Cell 16: 1506-1520.

Boonsirichai, K., Sedbrook, J. C., Chen, R., Gilroy, S., and Masson, P. H. (2003). ARG1 is a peripheral membrane protein that modulates gravity-induced cytoplasmic alkalinization and lateral auxin transport in plant statocytes. Plant Cell. 15: 2612-2625.

Sedbrook, J. C., Carroll, K.L., Hung, K.F., Masson, P.H. and Somerville, C.R. (2002). The Arabidopsis SKU5 gene encodes an extracellular glycosyl phosphatidylinositol-anchored glycoprotein involved in directional root growth. Plant Cell 14: 1635-1648.

Sedbrook, J. C., Chen, R. J., and Masson, P. H. (1999). ARG1 (Altered Response to Gravity) encodes a novel DnaJ-like protein that potentially interacts with the cytoskeleton. Proc. Natl. Acad Sci. USA 96: 1140-1145.

Lynn, K., Fernandez, A., Aida, M., Sedbrook, J., Tasaka, M., Masson, P., and Barton, M. K. (1999). The PINHEAD/ZWILLE gene acts pleiotropically in Arabidopsis development and has overlapping functions with the ARGONAUTE1 gene. Development 126: 469-481.

Chen, R., Hilson, P., Sedbrook, J., Rosen, E., Caspar, T., and Masson, P. H. (1998). The Arabidopsis thaliana AGRAVITROPIC1 gene encodes a component of the polar-auxin-transport efflux carrier. Proc. Natl. Acad Sci. USA 95: 15112-15117.

Sedbrook, J. C., Kronebusch, P. J., Borisy, G. G., Trewavas, A. J., and Masson, P. H. (1996). Transgenic AEQUORIN reveals organ-specific cytosolic Ca2+ responses to anoxia in Arabidopsis thaliana seedlings. Plant Physiol. 111: 243-257.

Hirschie Johnson, C., Knight, M. R., Kondo, T., Masson, P. Sedbrook, J., Haley, A., and Trewavas, A. (1995) Circadian oscillations of cytosolic and chloroplastic free calcium in plants. Science 269: 1863-1865.

Extramural Funding

The Department of Energy Great Lakes Bioenergy Research Center (GLBRC), 2007-2012. This is a $125 million Center based at the University of Wisconsin-Madison with a mission to perform basic and applied research aimed at breaking the barriers to the efficient and economic generation of biofuels from lignocellulosic biomass. Participants are located at the University of Wisconsin-Madison, Michigan State University, Illinois State University, Iowa State University, DOE Pacific Northwest National Laboratory, Lucigen Corporation, and C5 Technologies. Visit the GLBRC

The National Science Foundation, 2005-2009. Regulation of cell expansion and microtubule function by SPR1.