Abstract
The huge quantity of data generated by the "large scale" biology allows for <br />a new approach of developmental biology: an approach based on modeling at <br />a cellular level. Nowadays, genetic patterns and genetics pathways <br />involved in morphogenesis begin to be analyzable. In that context, it becomes <br />possible to understand how the plants architecture may be influenced by these <br />cellular or molecular scale mechanisms.<br /><br />In a first part of this work, tools dedicated to digitization and analysis of <br />cellular tissues and their evolution through time were developed. We set up <br />a software chain for quantitative analysis of morphological characteristics of <br />plant tissues through time, starting from images created using an acquisition <br />protocol based on confocal microscopy.<br /><br />Then, we developed a first growth model of the shoot apical meristem (a <br />population of stem cells in the plants) to study the initiation of lateral <br />organs. To account for existing biological knowledge, our model was developed <br />at organ scale. The genetic state, the physiological state and the growth of <br />each cell are simulated together with hormones fluxes between cells. This model <br />allowed for prediction and analysis of accumulation zones of hormones in <br />digitized meristems. Thanks to these studies, we were able to develop a dynamic <br />model of the meristem from which phyllotactic patterns emerge from cell growth <br />and cell-cell interactions.<br /><br />All the computer tools developed during this PhD have been integrated into <br />a multi-language software platform. In particular, this platform was used to <br />test different software development techniques involved in the integration of <br />compiled and interpreted languages in the context of morphogenesis study.