Laboratory of Plant Cell Biology
Department of Biology
University of Saskatchewan
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 fluorescent protein variants to dissect these elements in terms of their role in cell development.
Microtubules and the cell wall
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.
University of Saskatchewan
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 fluorescent protein variants to dissect these elements in terms of their role in cell development.
Microtubules and the cell wall
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.

Recent Papers
Zhang, Liyong, and Chris Ambrose. “CLASP Balances Two Competing Cell Division Plane Cues during Leaf Development.” Nature Plants 8, no. 6 (June 2022): 682–93.
-Featured as cover image
-Commentaries here.
-Press release here.