Abstract

Growth and morphogenesis requires the cell wall to expand irreversibly in a carefully controlled spatial and temporal pattern. How is this possible and how is it regulated? By developing better investigative tools we can improve our understanding of how this complex network of regulators is integrated with the physical parameters that underpin growth. To this end we developed ACME , an automated confocal micro extensometer, which enables simultaneous measurement of mechanical properties and visualisation with confocal microscopy. Using ACME we have investigated the material properties of growing tissues in response to hormones as well as in mutants with altered growth rates or anisotropy. We are able to make measurements with cellular resolution and have revealed spatial gradients in cell wall properties across tissues. In addition to measuring the mechanical properties that might underlie growth, we have investigated the possibility of feedback onto gene expression by applying stress or strain while imaging known molecular markers.