Assistant Professor
Adjunct, Department of Physics

Ph.D., University of North Carolina, Chapel Hill, 1996
Postdoctoral and Research Fellow, Stanford University, 2005

Program Affiliation: Molecular Biology & Genetics | Plant Biology

Research Groups Affiliation: Cell Biology | Development | Plant Biology

Phone: 812/856-5001
Fax: 812/855-6082
Email Sid

The Shaw laboratory studies how the microtubule cytoskeleton organizes and influences cellular morphogenesis.   We focus on the interphase microtubule arrays in Arabidopsis plants as a model for understanding how cells generate ordered patterns out of apparent chaos.   If the randomly arranged microtubules in a growing plant cell organize into a co-aligned array, like hoops around a barrel, the cell will elongate into a rod shape instead of a sphere.   The influence of the microtubules comes as a result of their ability to organize and reorganize in response to spatially defined cellular cues.   The fundamental mechanisms by which the microtubules recognize the cell axis, become co-aligned, and alter the cell wall properties to influence cell expansion are not yet known.

Using live-cell imaging techniques, computer simulation studies, and the powerful genetic tools available in the Arabidopsis system, we are discovering how the dynamic properties of the microtubule cytoskeleton contribute to the morphogenesis of the cell.   Our discovery that cortical microtubules reposition themselves through polymer treadmilling has dramatically reshaped the hypotheses for array organization.   Microtubule polymers in the plant cortical array 'move' when tubulin subunits bind to one end and concordantly unbind from the other.   This remarkable mechanism leads to microtubule interactions and other self-organizing behaviors currently under study.   Development of new imaging and image analysis technology in the lab, combined with the genetic resources in the Arabidopsis system, is providing exciting opportunity for studying cytoskeletal organization in the entire cell and quantitatively relating microtubule array pattern to anisotropic cell growth.

David Ehrhardt and Sidney L. Shaw (2006) Microtubule Dynamics and Organization in the Plant Cortical array. Annual Reviews in Plant Biology 57: 859-75.

Jacques Dumais, Sidney L. Shaw, Charles R. Steele, Sharon R. Long, and Peter M. Ray (2006)   An anisotropic-viscoplastic model of plant cell morphogenesis by tip growth.   International Journal of Development Biology 50: 209-222

Sidney L. Shaw (2006) Imaging and the live plant cell.   Plant Journal 45:573-598

Jacques Dumais, Sharon R. Long, Sidney L. Shaw (2004) The mechanics of surface expansion anisotropy in Medicago truncatula root hairs.   Plant Physiology 136(2):3266-3275

Raka Mitra, Sidney L. Shaw, Sharon Long (2004) Six non-nodulating plant mutants defective for Nod factor-induced transcriptional changes associated with the legume-rhizobia symbiosis.   PNAS 101(27)::10217-10222

Sidney L. Shaw, Roheena Kamyar and David W. Ehrhardt (2003)   Sustained microtubule treadmilling in Arabidopsis cortical arrays.   Science 300(5626):1715-1718 (Epub 2003 Apr 24)

Sidney L. Shaw and Sharon R. Long (2003)   Nod factor inhibits reactive oxygen production in a host legume. Plant Physiology 132(4):2196-2204

Besma Ben Amor, Sidney Shaw, Giles Oldroyd, Fabienne Maillet, R.Varma Penmetsa,   Douglas Cook, Sharon Long,   Jean Dénarié, and Clare Gough (2003)   The NFP locus of Medicago truncatula controls an early step of Nod factor signal transduction upstream of a rapid calcium flux and root hair deformation. Plant Journa l 34(4):495-506

Sidney L. Shaw and Sharon R. Long (2003)   Nod factor elicits two separable calcium responses in root hairs of Medicago truncatula .   Plant Physiology 131(3):976-984

Sidney L. Shaw, Jacques Dumais, and Sharon R. Long (2000)   Cell surface expansion of polarly growing root hairs of Medicago truncatula .   Plant Physiology 124(3):959-969