School of Engineering and Applied Sciences, Harvard University Cambridge, MA, USA.
Laboratoire de Reproduction et Développement des Plantes, Laboratoire Joliot Curie, Institut National de la Recherche Agronomique, CNRS, Ecole Normale Supérieure de Lyon, Université Claude Bernard Lyon 1 Lyon, France.
Front Plant Sci. 2012 Aug 9;3:174. doi: 10.3389/fpls.2012.00174. eCollection 2012.
The coordination of cell division and cell expansion are critical to normal development of tissues. In plants, cell wall mechanics and the there from arising cell shapes and mechanical stresses can regulate cell division and cell expansion and thereby tissue growth and morphology. Limited by experimental accessibility it remains unknown how cell division and expansion cooperatively affect tissue growth dynamics. Employing a cell-based two dimensional tissue simulation we investigate the regulatory role of a range of cell division rules on tissue growth dynamics and in particular on the spatial heterogeneity of growth. We find that random cell divisions only add noise to the growth and therefore increase growth heterogeneity, while cell divisions following the shortest new wall or along the direction of maximal mechanical stress reduce growth heterogeneity by actively enhancing the regulation of growth by mechanical stresses. Thus, we find that, beyond tissue geometry and topology, cell divisions affect the dynamics of growth, and that their signature is embedded in the statistics of tissue growth.
细胞分裂和细胞扩张的协调对组织的正常发育至关重要。在植物中，细胞壁力学以及由此产生的细胞形状和机械应力可以调节细胞分裂和细胞扩张，从而调节组织生长和形态。由于实验的可及性有限，细胞分裂和扩张如何协同影响组织生长动力学仍然未知。我们采用基于细胞的二维组织模拟方法，研究了一系列细胞分裂规则对组织生长动力学的调节作用，特别是对生长空间异质性的调节作用。我们发现，随机的细胞分裂只会给生长增加噪声，从而增加生长的异质性，而沿着最短的新壁或最大机械应力方向的细胞分裂通过积极增强机械应力对生长的调节作用，从而减少生长的异质性。因此，我们发现，除了组织几何形状和拓扑结构外，细胞分裂还会影响生长动力学，并且它们的特征嵌入在组织生长的统计数据中。
