A depth color-coded set of aligned confocal Z-sections of microtubule arrays (mCherry:TUA5) in Arabidopsis leaf epidermal pavement cells, which exhibit complex polarity. Unlike animal cells, plant cells are encapsulated by stiff cell walls that lie outside their plasma membranes. These walls provide structural support and help maintain cell shape, among other functions, but their presence also means that cell division operates very differently from animal cells. Indeed, plant growth depends on the regulated deposition of cell wall constituents, such as cellulose microfibrils. The cortical microtubule cytoskeleton influences the orientation of these cellulose microfibrils to generate complex cell shapes, such as the puzzle piece shape of pavement cells in the Arabidopsis thaliana leaf epidermis.
By Arun Sampathkumar and Elliot Meyerowitz, Sainsbury Laboratory, University of Cambridge