Fujita Hironori, Mochizuki Atsushi
Division of Theoretical Biology, National Institute for Basic Biology, Okazaki, Japan.
Dev Dyn. 2006 Oct;235(10):2710-21. doi: 10.1002/dvdy.20908.
The leaf venation pattern of plants shows remarkable diversity and species-specificity. However, the mechanism underlying the pattern formation and pattern diversity remains unclear. We developed a mathematical model that is based on the positive feedback regulation between plant hormone auxin and its efflux carrier. This system can generate auxin flow pathways by self-organization from an almost homogeneous state. This result explains a well-known experimental phenomenon referred as to "polar auxin transport." The model can produce diverse leaf venation patterns with spatial regularity under similar conditions to those of leaf development, that is, in the presence of leaf expansion and auxin sink. Final venation patterns are strikingly affected by leaf shape and leaf expansion. These results indicate that the positive feedback regulation between auxin and its efflux carrier is a central dynamic in leaf venation pattern formation. The diversity of leaf venation patterns in plant species is probably due to the differences of leaf shape and leaf expansion pattern.
植物的叶脉模式呈现出显著的多样性和物种特异性。然而，这种模式形成和模式多样性背后的机制仍不清楚。我们开发了一个基于植物激素生长素与其流出载体之间正反馈调节的数学模型。该系统能够通过自组织从几乎均匀的状态产生生长素流动路径。这一结果解释了一个被称为“极性生长素运输”的著名实验现象。该模型在与叶片发育相似的条件下，即在叶片扩展和生长素汇存在的情况下，能够产生具有空间规律性的多种叶脉模式。最终的叶脉模式受到叶片形状和叶片扩展的显著影响。这些结果表明，生长素与其流出载体之间的正反馈调节是叶脉模式形成的核心动力学过程。植物物种中叶脉模式的多样性可能是由于叶片形状和叶片扩展模式的差异所致。
