Microtubules and the shape of plants to come.

Plants control the direction of cell expansion as a way of shaping growth. Since their discovery in plants 40 years ago, microtubules have been suspected of forming a template that helps to regulate the direction of growth. The detailed mechanism, however, has been elusive, especially as plants lack a microtubule-organizing centre. Developmental mutants are now beginning to show how microtubules are organized and how this affects plant morphology.