Growth and morphogenesis at the vegetative shoot apex of Anagallis arvensis L.
Growth and morphogenesis at the vegetative shoot apex of Anagallis arvensis L.
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DOI：
10.1093/jxb/erg166
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发表时间：
2003-06-01
影响因子：
6.9
通讯作者：
Dumais, J
中科院分区：
文献类型：
--
作者：
Kwiatkowska, D;Dumais, J
采用非破坏性复型方法和三维重建算法，分析了茎尖表面的几何形状和膨胀情况。在顶点的中心区域中的表面膨胀是缓慢的并且接近各向同性的，而在外围区域中的表面膨胀是更强烈的并且更各向异性的。在周边区域内，膨胀率，膨胀各向异性，和最大膨胀的方向根据相邻叶原基的年龄而变化。对于每一个等时线，这种膨胀模式围绕顶点旋转斐波那契角。早期叶原基的发育可分为四个阶段：膨大、侧向扩展、分离和弯曲。这些阶段的几何形状和扩张模式各不相同。在膨胀阶段，原基起始部位表现出几乎各向同性的强烈膨胀。随后的阶段发展出膨胀率和各向异性的急剧的纬向梯度。从表面曲率推断的近轴原基边界转移，直到分离阶段，当折痕之间的原基和顶圆顶的发展。形成折痕的细胞，即未来的叶腋，沿着叶腋伸展，然后在叶腋上收缩，因此它们被固定在这个独特的位置。
A non-destructive replica method and a 3-D reconstruction algorithm are used to analyse the geometry and expansion of the shoot apex surface. Surface expansion in the central zone of the apex is slow and nearly isotropic while surface expansion in the peripheral zone is more intense and more anisotropic. Within the peripheral zone, the expansion rate, expansion anisotropy, and the direction of maximal expansion vary according to the age of adjacent leaf primordia. For each plastochron, this pattern of expansion is rotated around the apex by the Fibonacci angle. Early leaf primordium development is divided into four stages: bulging, lateral expansion, separation, and bending. These stages differ in their geometry and expansion pattern. At the bulging stage, the site of primordium initiation shows an intensified expansion that is nearly isotropic. The following stages develop sharp meridional gradients of expansion rates and anisotropy. The adaxial primordium boundary inferred from the surface curvature is shifting until the separation stage, when a crease develops between the primordium and the apex dome. The cells forming the crease, i.e. the future leaf axil, expand along the axil and contract across it. Thus they are arrested in this unique position.