An auxin-driven polarized transport model for phyllotaxis
An auxin-driven polarized transport model for phyllotaxis
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DOI：
10.1073/pnas.0509839103
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发表时间：
2006-01-31
影响因子：
11.1
通讯作者：
Mjolsness, E
中科院分区：
文献类型：
--
作者：
Jönsson, H;Heisler, MG;Mjolsness, E
最近的研究表明，植物器官定位可能是由植物激素生长素的局部浓度介导的。芽根尖分生组织中的生长素图案又是由推定的生长素外排介质PIN1的亚细胞极性分布所带来的。但是，哪些信号决定PIN1极化的问题以及如何引起生长素浓度的常规模式，这仍然未知。在这里，我们通过使用数学建模与共聚焦成像结合来解决这些问题。我们提出了一个基于生长素在分生组织表皮中影响其自身外排的极化的假设的模型。我们表明，这种模型足以在具有静态和动态细胞连接的系统上创建生长素浓度的常规空间模式，后者由机械模型控制。我们还通过使用详细的生长素传输模型来优化PIN1动力学的参数值，该模型从实验估计中获取参数值，以及由单元格和壁隔室组成的模板以及从共焦数据定量提取的PIN1浓度。该模型显示了极化运输如何驱动常规图案的形成。
Recent studies show that plant organ positioning may be mediated by localized concentrations of the plant hormone auxin. Auxin patterning in the shoot apical meristem is in turn brought about by the subcellular polar distribution of the putative auxin efflux mediator, PIN1. However, the question of what signals determine PIN1 polarization and how this gives rise to regular patterns of auxin concentration remains unknown. Here we address these questions by using mathematical modeling combined with confocal imaging. We propose a model that is based on the assumption that auxin influences the polarization of its own efflux within the meristem epidermis. We show that such a model is sufficient to create regular spatial patterns of auxin concentration on systems with static and dynamic cellular connectivities, the latter governed by a mechanical model. We also optimize parameter values for the PIN1 dynamics by using a detailed auxin transport model, for which parameter values are taken from experimental estimates, together with a template consisting of cell and wall compartments as well as PIN1 concentrations quantitatively extracted from confocal data. The model shows how polarized transport can drive the formation of regular patterns.