ALLOMETRY OF CELLS AND TISSUES WITHIN LEAVES
ALLOMETRY OF CELLS AND TISSUES WITHIN LEAVES
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DOI：
10.3732/ajb.1200608
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发表时间：
2013-10-01
影响因子：
3
通讯作者：
Sack, Lawren
中科院分区：
文献类型：
--
作者：
John, Grace P.;Scoffoni, Christine;Sack, Lawren
研究前提：叶细胞、细胞壁和组织的尺寸以及全叶厚度和面积之间的异速生长关系可能对叶片结构和功能产生关键影响，但实际上尚未经过测试，尽管人们对更大规模的众多植物特性的异速生长分析的兴趣激增。方法：使用叶片横截面和光学显微镜，我们测量了叶片尺寸、组织厚度、叶肉 研究了潮湿和干燥栖息地的 14 种不同被子植物物种的木质部细胞大小和细胞壁厚度，并测试了基于发育和/或功能引起的几何缩放的假设的异速生长关系。主要结果：我们发现了与细胞、细胞壁、组织和总叶形状相关的强大的新颖异速生长关系。细胞大小和细胞壁厚度往往在叶子内的叶肉组织中等轴缩放，因此在一个组织中具有大细胞或厚细胞壁的物种在其他组织中也具有这些特征；然而，叶脉木质部导管的大小与其他细胞类型的大小无关。我们还发现整个叶肉的细胞壁厚度与细胞大小存在强烈的几何缩放关系，但叶脉木质部却没有。此外，叶子厚度与细胞大小、细胞壁厚度和组成叶肉组织的厚度成比例，但叶面积与物种之间的解剖特征无关。结论：这些新颖的异速生长表明在叶子结构的最小尺度上运行的设计规则，以及应用这些关系来更好地表征物种间叶子形状和功能特征差异的基础的可能性。
Premise of the study: Allometric relationships among the dimensions of leaf cells, cell walls, and tissues, and whole-leaf thickness and area are likely to have key implications for leaf construction and function, but have remained virtually untested, despite the explosion of interest in allometric analysis of numerous plant properties at larger scales.Methods: Using leaf transverse cross sections and light microscopy, we measured leaf dimensions, tissue thicknesses, mesophyll and xylem cell sizes, and cell wall thicknesses for 14 diverse angiosperm species of wet and dry habitats and tested hypothesized allometric relationships based on geometric scaling due to development and/or function.Key results: We found strong novel allometries relating the dimensions of cells, cell walls, tissues, and gross leaf form. Cell sizes and cell wall thicknesses tended to scale isometrically across mesophyll tissues within the leaf, such that species with large cells or thick cell walls in one tissue had these also in the other tissues; however, leaf vein xylem conduit sizes were independent of those of other cell types. We also found strong geometric scaling of cell wall thicknesses with cell sizes throughout the mesophyll, but not in the leaf vein xylem. Further, leaf thickness scaled with cell sizes, cell wall thicknesses and the thicknesses of component mesophyll tissues, but leaf area was independent of anatomical traits across species.Conclusions: These novel allometries suggest design rules operating at the smallest scales of leaf construction and the possibility of applying these relationships to better characterizing the basis for differences among species in leaf form and functional traits.