Leaves have highly diverse morphologies. However, with an evolutionary history of approximately 200 million years, leaves of the pine family are relatively monotonous and often collectively called “needles”, although they vary in length, width and cross-section shapes. It would be of great interest to determine whether Pinaceae leaves share similar morpho-physiological features and even consistent developmental and adaptive mechanisms. Based on a detailed morpho-anatomical study of leaves from all 11 Pinaceae genera, we particularly investigated the expression patterns of adaxial-abaxial polarity genes in two types of leaves (needlelike and flattened) and compared their photosynthetic capacities. We found that the two types of leaves share conserved spatial patterning of vasculatures and genetic networks for adaxial-abaxial polarity, although they display different anatomical structures in the mesophyll tissue differentiation and distribution direction. In addition, the species with needlelike leaves exhibited better photosynthetic capacity than the species with flattened leaves. Our study provides the first evidence for the existence of a conserved genetic module controlling adaxial-abaxial polarity in the development of different Pinaceae leaves.

中文翻译：

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松科（Pinaceae）的扁平和针状叶片共享一个保守的遗传网络，用于前后轴极性，但为了光合适应而发散

叶子具有高度多样的形态。然而，具有大约2亿年的进化历史，尽管其长度，宽度和横截面形状各不相同，但松树的叶子相对单调，通常统称为“针”。确定松科植物的叶子是否具有相似的形态生理特征，甚至一致的发育和适应机制，将是非常令人感兴趣的。基于对11个松科属植物的叶片进行详细的形态解剖学研究，我们特别研究了两类叶片（针状和扁平状）的近轴-反极性基因的表达模式，并比较了它们的光合能力。我们发现这两种类型的叶子共享脉管系统和遗传网络的守恒空间格局，用于左右轴极性，尽管它们在叶肉组织分化和分布方向上显示出不同的解剖结构。另外，具有针状叶的物种比具有扁平叶的物种表现出更好的光合能力。我们的研究提供了第一个证据，证明在不同松科植物叶片发育过程中存在控制遗传基因模块的保守遗传模块。