The preprophase band of microtubules controls the robustness of division orientation in plants

Refined understanding of the preprophase band Because plant cells do not move, plant tissues are constructed according to how they place the divisions of their constituent cells. Schaefer et al. found a mutation in the model plant Arabidopsis that abolishes a visible precursor of cell division, the preprophase band. Despite loss of the band—previously thought essential to define the division plane—the general orientations of cell division planes in the roots of these plants were normal. However, individual division orientations showed more variance than normal. Thus, the preprophase band serves to focus and refine the final orientation of the nascent cell division plane. Science , this issue p. 186