PT - JOURNAL ARTICLE AU - Graeme Mitchison TI - Conformal growth of <em>Arabidopsis</em> leaves AID - 10.1101/048199 DP - 2016 Jan 01 TA - bioRxiv PG - 048199 4099 - http://biorxiv.org/content/early/2016/04/21/048199.short 4100 - http://biorxiv.org/content/early/2016/04/21/048199.full AB - I show that Arabidopsis leaf growth can be described with good precision by a conformal map, where expansion is locally isotropic (the same in all directions) but the amount of expansion can vary with position. Data obtained by tracking leaf growth over time can be reproduced with almost 90% accuracy by such a map. The growth follows a Moebius transformation, which is a type of conformal map that would arise if there were an underlying linear gradient of growth rate. From the data one can derive the parameters that describe this linear gradient and show how it changes over time. Growth according to a conformal map has the property of maintaining the flatness of a leaf.