Daniel B. Szymanski
|Telephone:||765-494-8092||Office Location: 2353 Lilly Hall of Life Sciences and 226 WSLR|
|FAX:||765-496-2926||Plant Genetics and Breeding Group|
B.S. University of Michigan
Ph.D. University of Illinois
Agronomy 320 Genetics
Mechanisms of growth and environmental response in plant cells
In plants the microtubule and actin cytoskeletons form an interconnected array of filaments that span the cytoplasmic space of the cell. The cytoskeleton is required for normal cell division and growth. For example, the actin cytoskeleton provides the tracks on which organelles and vesicles move during cell expansion. The organization of the actin cytoskeleton determines where cell growth occurs. Unfortunately our understanding of actin organization is limited. Mechanistic insight into this important problem will require a molecular genetic approach. I am using leaf epidermal development in Arabidopsis as a model process to understand the function and organization of the actin cytoskeleton during plant cell growth.
|Arabidopsis leaf development is an excellent experimental system to study this problem. The leaf epidermis contains several highly polarized cell types, including trichomes or hair cells, which display unique responses to microtubule and actin microfilament-disrupting agents (Szymanski et al. 1999, see scanning electron micrograph of Arabidopsis trichomes, Panel 1). Therefore it has been possible to selectively screen for mutations that affect cytoskeletal function during epidermal cell growth (see immunolocalization and confocal fluorescence image of actin filaments in a wild-type trichome, panel 2). For example, disruption of the SPIKE1 gene causes defects in actin organization, cell shape, epidermal cell adherence, and fertility. The SPIKE1 gene shares extensive amino acid identity with the DOCK180 family of proteins. In humans, Drosophila, and C. elegans DOCK180 proteins are essential for transmitting extracellular signals to proteins that locally regulate actin organization. The use of modern molecular genetic, biochemical, and live-cell imaging tools in this experimental system will make fundamental contributions to the field of cytoskeletal control and morphogenesis.||
groups I am involved in:
Plant Biology Program, an interdisciplinary plant research program at Purdue that provides graduate student support
Zhang, C., Mallery, E. L., Schlueter, J., Huang, S., Fan, Y., Brankle, S. Staiger, C.J., and Szymanski, D.B. 2008 Arabidopsis SCARs function interchangeably to meet ARP2/3-activation thresholds during morphogenesis. Plant Cell 20, 995-1011.
Basu, D. , Le, J., Zakharova, T., Mallery, E.L., and Szymanski, D.B. 2008 A SPIKE1 signaling complex controls actin-dependent morphogenesis through the WAVE and ARP2/3 complexes. PNAS USA 105, 4044-4049.
Le, J. Mallery, E.L., Zhang, C., Brankle, S., and Szymanski, D.B. 2006 Arabidopsis BRICK1/HSPC300 Is an Essential WAVE-Complex Subunit that Selectively Stabilizes the Arp2/3 Activator SCAR2. Curr. Biol. 16, 895-901.
Basu, D., Le, J., El-Essal, S., Huang, S., Zhang, C., Mallery, E.L., Koliantz, G., Staiger, C., Szymanski, D.B. 2005 DISTORTED3/SCAR2 Is a Putative Arabidopsis WAVE Complex Subunit That Activates the Arp2/3 Complex and Is Required for Epidermal Morphogenesis. Plant Cell 17: 502-524.
Szymanski, D.B. 2004 Breaking the WAVE complex: the point of Arabdidopsis trichomes. Curr. Opin. Plant Biol. (published online 11/1/2004).
Basu, D., El-Assal, S., Le, J., Mallery, E., Szymanski, D.B. 2004 Interchangeable functions of Arabidopsis PIROGI and the human WAVE complex subunit SRA1 during leaf epidermal development. Development 131: 4345-4355.
El-Assal, S., Le, J., Basu, D., Mallery, E.L., Szymanski, D.B. 2004 Arabidopsis GNARLED Encodes a NAP125 Homolog that Positively Regulates ARP2/3. Curr. Biol. 14: 1405-1409.
El-Assal, S., Le, J., Basu, D., Mallery, E.L., Szymanski, D.B. 2004 DISTORTED2 encodes an ARPC2 subunit of the putative Arabidopsis ARP2/3 complex. Plant J. 38(3): 526-38.
El-Assai, S.E., Basu, D., Saad, M.E., Szymanski, D.B. 2003
Requirements for Arabidopsis ATARP2 and ATARP3 during epidermal
development. Current Biol. 13: 1341-1347.
Le, J., El-Assai, S.E., Basu, D., Saad, M.E., Szymanski, D.B. 2003 Supplemental Data: Requirements for Arabidopsis ATARP2 and ATARP3 during epidermal development. Current Biol. 13: 1341-1347.
Qiu, J.L, Jilk, R., Marks, M.D., Szymanski, D.B.. 2002 The Arabidopsis SPIKE1 gene is required for normal cell shape control and tissue development. Plant Cell 14: 101-118.
Szymanski, D.B. 2001 Arabidopsis trichome morphogenesis: a genetic approach to studying cytoskeletal function. J. Plant Growth Regulation 20: 131-140.
Szymanski, D.B. 2001 Arabidopsis thaliana: the premiere model plant, in Encyclopedia of Genetics. (Brenner, S and Miller, J.H. eds) Academic Press.
Szymanski, D.B. The role of actin during Arabidopsis trichome morphogenesis, in Actin: a dynamic framework for multiple plant cell functions (Staiger, C.J et al., eds,) Kluwer 2000.
Szymanski D.B., Lloyd A.M. and Marks D.M. Progress in the molecular genetic analysis of trichome initiation and morphogenesis in Arabidopsis. 2000 Trends Plant Sci. 5: 214-219.
Szymanski, D.B., Marks, M.D., Wick, S.M. Organized F-actin is essential for normal Arabidopsis trichome morphogenesis. 1999 Plant Cell 11: 2331-2347.