- Cellular origins of plant shape
- Microtubules, cell walls and cell shape
- How patterns of cell division, expansion, and differentiation influence the growth and morphology of tissues, organs, and organism
actin cell biology cell wall cytoskeleton membrane microscopy microtubule
Selection of Publications (by Year)
- Liyong Zhang, Delanie McEvoy, Yen Le, Chris Ambrose. "Live Imaging of Microtubule Organization, Cell Expansion, and Intercellular Space Formation in Arabidopsis Leaf Spongy Mesophyll Cells". The Plant Cell 33, 3 (2021): 623-641.
- Arun Shunmugam, et. al. "MeioCapture: An Efficient Method for Staging and Isolation of Meiocytes in the Prophase I Sub-Stages of Meiosis in Wheat". BMC Plant Biology 18, 1 (2018)
- Yuan Ruan, et. al. "The Microtubule-Associated Protein CLASP Sustains Cell Proliferation through a Brassinosteroid Signaling Negative Feedback Loop". Current Biology 28, 17 (2018): 2718-2729.
- Yen Le, Chris Ambrose. "CLASP Promotes Stable Tethering of Endoplasmic Microtubules to the Cell Cortex to Maintain Cytoplasmic Stability in Arabidopsis Meristematic Cells". PloS One 13, 6 (2018)
- Katherine Celler, Miki Fujita, Eiko Kawamura, Chris Ambrose, Klaus Herburger, Andreas Holzinger, and Geoffrey O. Wasteneys. "Microtubules in Plant Cells: Strategies and Methods for Immunofluorescence, Transmission Electron Microscopy and Live Cell Imaging." In Cytoskeleton Methods and Protocols, 3rd, edited by Gavin, Ray H, 155-184. New York: Springer, 2015.
- Ambrose, J, Geoffrey Wasteneys. "Microtubule initiation from the nuclear surface controls cortical microtubule growth polarity and orientation in Arabidopsis thaliana". Plant Cell and Physiology 55, 9 (2014): 1636-1645.
- Ambrose, J, Yuan Ruan, John Gardiner, Laura Tamblyn, Amanda Catching, Viktor Kirik, Jan Marc, Robyn Overall, Geoffrey O. Wasteneys. "CLASP Interacts with Sorting Nexin 1 to Link Microtubules and Auxin Transport via PIN2 Recycling in Arabidopsis thaliana". Develpomental Cell 24, 6 (2013): 649-659.
- Ambrose JC*, Allan DeBono*, Geoffrey O. Wasteneys. "Cell geometry guides the dynamic targeting of apoplastic GPI-linked Lipid Transfer Protein to cell wall elements and cell borders in Arabidopsis thaliana". PLOS One 8, 11 (2013): e81215-*Authors contributed equally.
- Ambrose, J, Allard JF, Cytrynbaum EN, Wasteneys GO. "A cell-edge-barrier mechanism drives cell-wide cortical microtubule orientation in Arabidopsis". Nature Communications 2, 430 (2011): 430.
- Ambrose, J, Wasteneys, GO. "Cell edges accumulate gamma tubulin complex components and nucleate microtubules following cytokinesis in Arabidopsis thaliana cells". PLOS One 6, 11 (2011)
- Ambrose, J. "Nanoscale and geometric influences on the microtubule cytoskeleton in plants; thinking inside and outside the box". Protoplasma 249 (2011)
- Allard JF, Ambrose JC, Wasteneys GO, Cytrynbaum EN. "A mechanochemical model explains interactions between cortical microtubules in plants". Biophysical Journal 4 (2010): 1082-1090.
- Wasteneys, GO, Ambrose, JC. "Spatial organization of plant cortical microtubules: close encounters of the 2D kind". Trends in Cell Biology 19 (2009): 62-71.
- Ambrose, Chris, Cyr, Richard. "Mitotic Spindle Organization by the Preprophase Band.". Mol Plant 1 (2008): 950-960.
- Ambrose, C, Wasteneys, GO. "CLASP modulates microtubule-cortex interaction during self-organization of acentrosomal microtubules". Mol Biol Cell 19 (2008): 4730-4737.
- Ambrose, J, Cyr, RJ. "Mitotic Spindle Assembly and Function" In Cell Division Control in Plants, edited by D.P.S. Verma and Z. Hong, 141-167. Berlin Heidelberg: Springer-Verlag, 2007.
- Ambrose, J.C., Li, W., Marcus, A., Ma, H., and Cyr, R. "A minus-end-directed kinesin with plus-end tracking protein activity is involved in spindle morphogenesis.". Mol Biol Cell 16 (2005): 1584-1592.
- Marcus, A.I., Ambrose, J.C., Blickley, L., Hancock, W.O., and Cyr, R.J. "Arabidopsis thaliana protein, ATK1, is a minus-end directed kinesin that exhibits non-processive movement.". Cell Motil Cytoskeleton 52 (2002): 144-150.
Teaching & Supervision
cell biology plant biology plant development
Biology 325; Plant Cells and Tissues
Covers plant form and function ranging from large-scale tissue and organ developmental processes to subcellular molecular processes.
Selection of Courses Taught (by Year)
- 2004 - Pennylvania State University, Plant Anatomy and Development
- 2006 - Pennsylvania State University, Biology of Molecules and Cells
- 2015 - Plant Cells and Tissues
- 2016 - The Living Plant
actin cell adhesion cell biology cell division cell wall cytoskeleton endomembrane imaging microtubule
The cellular origins of plant shape
Plant shape is defined by controlling where, when, and how cells divide and expand. Our group is interested in how patterns of cell division, expansion, and differentiation influence the growth and morphology of tissues, organs and organism. The main subcellular components governing cellular differentiation include the microtubule and actin cytoskeletons, the cell wall, and membrane/endomembrane system. Using the model plant Arabidopsis thaliana, we use molecular-genetics and live-cell imaging of green fluorescent protein variants to dissect these elements in terms of their role in cell development.
Microtubules, cell walls and cell shape
Control of cell division and differentiation relies heavily on the microtubule cytoskeleton; a complex network of tubulin polymers that dynamically arrange into a variety of three-dimensional configurations. As in all eukaryotic cells, microtubules in plants also function to define cellular polarity and shape, separate chromosomes, drive cytokinesis, and carry a variety of organelles and molecules around the cell. With respect to cell wall function, two plant-specific microtubule assemblies—the cytokinetic phragmoplast and the interphase cortical array—are paramount. The phragmoplast drives cell plate formation and expansion during cytokinesis, and the cortical array lines the cell cortex in varied microtubule patterns (parallel, net-like, and large bundles), where it influences the orientation and structure of cellulose microfibrils within the surrounding cell wall, thereby defining how cells expand in response to cellular turgor pressure.
Education & Training
PhD - The Pennsylvania State University, University Park, PA (2000-2006).
- Life Science Consortium’s Integrative Biosciences (IBIOS)
- Ecological and Molecular Plant Physiology
- Laboratory of Professor Richard Cyr.
- Research Area: Microtubule cytoskeleton, cell division, cell and molecular biology.
- Dissertation Title: The Roles of Molecular Motors and Microtubule Dynamics in the Assembly and Function of the Higher Plant Mitotic Spindle.
BS - Millersville University, Millersville, PA (1995-2000).
- Biology major, Biochemistry minor
- Specialization in Plant Biology
Documents & Links
DIC microscopy showing a timelapse of cell division in cultured BY-2 cells.
The image is a trick; it is actually a compression of three sequential time points from a timelapse. Each matchtip-shaped structure is a microtubule plus end. Three timepoints colored red, blue, green.
Note the bulgy epidermal cells, which are characteristic of mutants with microtubule defects. In this case, the line is the botero-1 mutant, which lacks microtubule severing activity, and has abnormal microtubule organization.
Arabidopsis leaf expressing YFP-LTPG (Lipid-Transfer Protein GPI-Linked). Note strong accumulation at the outlines of the cells of the epidermis. A huge trichome also makes an appearance, showing its multiple spikes and characteristic speckling by papillae.
Courtesy of Eiko Kawamura. Shows the beautiful patterns of cellular organization in a developing leaf.