DYNAMIC MICROTUBULES - IMPLICATIONS FOR CELL-WALL PATTERNS

The shape of plant cells is thought to depend largely on the relations hip between cortical microtubules (MTs) and cellulose microfibrils in the cell wall. As templates for the deposition of newly polymerized mi crofibrils, MTs indirectly influence the direction of cell expansion, and this parallelism between MTs and microfibrils is therefore a centr al aspect of plant morphogenesis. However, microfibrils can change the ir alignment with each new layer that is deposited in the cell wall, a nd it was unclear until recently how MTs could undergo corresponding r eorientations. Now, microinjection studies have begun to show how MTs rapidly interconvert between complex three-dimensional configurations, allowing models for the construction and behaviour of the MT array to be revised.