Tsukaya Hirokazu
National Institute for Basic Biology/Centre for Integrated Bioscience, Okazaki National Institutes, Myodaiji-cho, Japan.
Curr Opin Plant Biol. 2003 Feb;6(1):57-62. doi: 10.1016/s1369526602000055.
Control of the shape and size of indeterminate organs, such as roots and stems, is directly related to the control of the shape and size of the cells in these organs, as predicted by orthodox cell theory. For example, the polarity-dependent growth of leaf cells directly affects the polar expansion of leaves. Thus, the control of leaf shape is related to the control of the shape of cells within the leaf, as suggested by cell theory. By contrast, in determinate organs, such as leaves, the number of cells does not necessarily reflect organ shape or size. Genetic evidence shows that a compensatory system(s) is involved in leaf morphogenesis, and that an increase in cell volume can be triggered by a decrease in cell number and vice versa. Studies of chimeric leaves also suggest interaction between leaf cells that coordinates the behaviour of these cells at the organ level. Moreover, leaf size also appears to be coordinated at the whole-plant level. The recently hypothesised neo cell theory describes how leaf shape- and size-control mechanisms control leaf shape at the organ-level via cell-cell interaction.
正如正统细胞理论所预测的那样，对不定器官（如根和茎）的形状和大小的控制直接关系到这些器官中细胞的形状和大小的控制。例如，叶细胞的极性依赖性生长直接影响叶片的极性扩展。因此，正如细胞理论所表明的，叶片形状的控制与叶片内细胞形状的控制有关。相比之下，在确定器官（如叶片）中，细胞数量不一定反映器官的形状或大小。遗传证据表明，一个补偿系统参与叶片形态发生，并且细胞数量的减少可以触发细胞体积的增加，反之亦然。对嵌合叶的研究也表明叶细胞之间存在相互作用，这种相互作用在器官水平上协调这些细胞的行为。此外，叶片大小似乎也在整株植物水平上得到协调。最近提出的新细胞理论描述了叶片形状和大小控制机制如何通过细胞间相互作用在器官水平上控制叶片形状。
