Cellular Dynamics in Plants
Description of Cellular Dynamics
Plants are sessile organisms and their cells are fixed in position from birth. However, plant cells are amazingly dynamic in many ways. The cell wall slowly remodels its polymer, as polysaccharides are deposited through the combined activities of a dynamic integral membrane protein complex and trafficking of vesicles to the plasma membrane. The plant cytoplasm undergoes a flurry of activity, constantly remodelling to accurately target the multiprotein complexes, transporters and small molecules that control plant form.
Scientists in this hot topic area investigate: the role of a dynamic cytoskeleton during cellular morphogenesis, cell signaling and response to pathogens; transport of hormones through the plant body and across cellular membranes; import of protein-nucleic acid complexes into the nucleus; synthesis and deposition of cell wall polysaccharides; and developmental control over cell size. Student's training in a cellular dynamics lab will take advantage of state-of-the-art imaging technologies; advanced biochemical, proteomics and biophysical approaches; and, forward or reverse-genetic approaches in model organisms.
Bimolecular fluorescence complementation showing interactions between VirE2 and the host nuclear trafficking proteins, the IMPORTINs.
Timelapse composite image of cortical actin filaments from a live cell expressing a fluorescent fusion protein shows the marked rearrangements that occur within just 3 sec.
Bhattacharjee, S., Lee, L.-Y., Oltmanns, H. Cao, H., Veena, Cuperus, J., and Gelvin, S.B. 2008. AtImpa-4, an Arabidopsis importin a isoform, is preferentially involved in Agrobacterium -mediated plant transformation. Plant Cell 20: 2661-2680.
The Gelvin laboratory investigates genes and proteins important for Agrobacterium -mediated plant genetic transformation. The Agrobacterium VirE2 effector protein is mobilized from the bacterium to the plant where it interacts with transferred T-DNA and helps target it to the nucleus. This 2008 Plant cell paper shows how the bacterial protein VirE2 and host plant proteins are involved in the intracellular trafficking of T-DNA to the nucleus.
Staiger, CJ, MB Sheahan, P Khurana, X Wang, DW McCurdy, and L Blanchoin (2009) Actin filament dynamics are dominated by rapid growth and severing activity in the Arabidopsis cortical array. J. Cell Biol. 184: 269-280. http://jcb.rupress.org/cgi/content/full/184/2/269
Using a unique mode of fluorescence imaging, this study examines cortical cytoskeleton dynamics in living, expanding epidermal cells. The growth and disappearance of individual actin filaments is extremely fast and occurs by a process called stochastic dynamics'. These new finding are fundamentally different from textbook models of actin behavior and highlights the importance of studying cellular dynamics in plant systems.