Department of Biological Sciences, University of Alberta, Edmonton AB, Canada.
Cold Spring Harb Perspect Biol. 2010 Jan;2(1):a001511. doi: 10.1101/cshperspect.a001511.
Leaves are the main photosynthetic organs of vascular plants and show considerable diversity in their geometries, ranging from simple spoon-like forms to complex shapes with individual leaflets, as in compound leaves. Leaf vascular tissues, which act as conduits of both nutrients and signaling information, are organized in networks of different architectures that usually mirror the surrounding leaf shape. Understanding the processes that endow leaves and vein networks with ordered and closely aligned shapes has captured the attention of biologists and mathematicians since antiquity. Recent work has suggested that the growth regulator auxin has a key role in both initiation and elaboration of final morphology of both leaves and vascular networks. A key feature of auxin action is the existence of feedback loops through which auxin regulates its own transport. These feedbacks may facilitate the iterative generation of basic modules that underlies morphogenesis of both leaves and vasculature.
叶片是维管植物的主要光合作用器官，在几何形状上表现出相当大的多样性，从简单的匙形到具有小叶的复杂形状，如复叶。作为营养物质和信号信息的导管，叶片维管束组织以不同结构的网络形式组织，通常反映周围叶片的形状。自古以来，生物学家和数学家就一直关注赋予叶片和叶脉网络有序且紧密排列形状的过程。最近的研究表明，生长调节剂生长素在叶片和叶脉网络最终形态的起始和细化中都起着关键作用。生长素作用的一个关键特征是存在反馈环，通过这些反馈环生长素可以调节自身的运输。这些反馈可能有助于基本模块的迭代生成，而这些基本模块是叶片和脉管系统形态发生的基础。
