Cellular basis of hypocotyl growth in Arabidopsis thaliana
Cellular basis of hypocotyl growth in Arabidopsis thaliana
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DOI：
10.1104/pp.114.1.295
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发表时间：
1997-05-01
期刊：
影响因子：
7.4
通讯作者：
Hofte, H
中科院分区：
文献类型：
--
作者：
Gendreau, E;Traas, J;Hofte, H
拟南芥下胚轴被广泛用于研究光和植物生长因子对细胞伸长的影响。为了提供一个框架，在这个器官中的细胞伸长的分子遗传学分析，在这里，我们描述，在细胞水平上，其形态和生长，并确定了一些特征，光生长和黑暗生长的下胚轴之间的发育差异。首先，在光下表皮细胞显示出在黑暗中观察不到的特征性分化。其次，该器官的伸长生长不涉及显著的皮层或表皮细胞分裂。然而，核内复制发生，如4C和8 C核的存在所揭示的。此外，16 C核被发现专门在黑暗生长的幼苗。第三，在黑暗中，表皮细胞沿着下胚轴伸长，沿沿着一个陡峭的向顶的空间和时间梯度。相反，在光下，所有表皮细胞在整个生长期内连续伸长。这些形态和生理差异，结合以前报道的遗传数据（T。Desnos，V. Orbovic，C.作者：J. Caboche，J. Traas，H. Hofte [1996] Development 122：683-693）阐明了光并不简单地以细胞自主方式抑制下胚轴生长，而是所观察到的对光的生长响应是整个伸长器官的综合发育变化的一部分。
The Arabidopsis thaliana hypocotyl is widely used to study the effects of light and plant growth factors on cell elongation. To provide a framework for the molecular-genetic analysis of cell elongation in this organ, here we describe, at the cellular level, its morphology and growth and identify a number of characteristic, developmental differences between light-grown and dark-grown hypocotyls. First, in the light epidermal cells show a characteristic differentiation that is not observed in the dark. Second, elongation growth of this organ does not involve significant cortical or epidermal cell divisions. However, endoreduplication occurs, as revealed by the presence of 4C and 8C nuclei. In addition, 16C nuclei were found specifically in dark-grown seedlings. Third, in the dark epidermal cells elongate along a steep, acropetal spatial and temporal gradient along the hypocotyl. In contrast, in the light all epidermal cells elongated continuously during the entire growth period. These morphological and physiological differences, in combination with previously reported genetic data (T. Desnos, V. Orbovic, C. Bellini, J. Kronenberger, M. Caboche, J. Traas, H. Hofte [1996] Development 122: 683-693), illustrate that light does not simply inhibit hypocotyl growth in a cell-autonomous fashion, but that the observed growth response to light is a part of an integrated developmental change throughout the elongating organ.