Stress-induced alignment of division plane in plant tissues grown in vitro

Abstract

The architectural nature of cell patterns in plants, which are visible under the light microscope, offers strong intuitive evidence for a structural relationship between mechanical forces acting through the tissue and cell wall orientation at cytokinesis. However, a direct relationship between the two has never been convincingly established. We find that compressive forces at intensities between 500 and 800 mg mm⁻² can induce a conspicuous spatial ordering of division activity when applied to sterile plant tissues during continued growth in culture; this results in cambium-like areas of cell wall co-planarity which are clearly distinguishable from the characteristically disorganized growth of unstressed regions of the explant, and implies the presence of an intracellular structural–mechanical sensor capable of directing the installation of the new cell partition. The experiment reported here, in which compressive forces were applied to plant tissue growing in vitro, provides an example of mechanical control of division plane.