Towards an understanding of spiral patterning in the Sargassum muticum shoot apex.
Towards an understanding of spiral patterning in the Sargassum muticum shoot apex.
复制标题
DOI：
10.1038/s41598-017-13767-5
复制
发表时间：
2017-10-24
影响因子：
4.6
通讯作者：
Braybrook SA
中科院分区：
文献类型：
--
作者：
Linardić M;Braybrook SA
在植物和薄壁褐藻中，身体通过顶端分生组织（细胞或单个细胞的生态位）的活动而产生。分生组织以特定的模式产生侧壁器官，称为叶状排列。在植物中，已经提出了两种不同的控制机制：一种是位置依赖性的，依赖于未来器官部位形态素的积累；另一种是基于谱系的系统，它将叶状分化与顶端细胞分裂模式联系起来。在这里，我们研究了褐藻马尾藻（Sargassum muticum）的顶端模式，它表现出螺旋叶状排列（137.5°角）和不相连的顶端细胞分裂模式。马尾藻顶端具有自组织系统的特征，类似于植物的分生组织。与复杂的植物分生组织相比，我们无法将马尾藻的植物形态素生长素与芽定位联系起来，也无法预测新芽位置的细胞壁软化。我们的数据表明，在马尾藻中，叶状分化和顶端细胞分裂模式之间没有联系，表明可能存在位置依赖的模式机制。层序模式背后的潜在机制似乎与在植物中看到的不同。
In plants and parenchymatous brown algae the body arises through the activity of an apical meristem (a niche of cells or a single cell). The meristem produces lateral organs in specific patterns, referred to as phyllotaxis. In plants, two different control mechanisms have been proposed: one is position-dependent and relies on morphogen accumulation at future organ sites; the other is a lineage-based system which links phyllotaxis to the apical cell division pattern. Here we examine the apical patterning of the brown alga, Sargassum muticum, which exhibits spiral phyllotaxis (137.5° angle) and an unlinked apical cell division pattern. The Sargassum apex presents characteristics of a self-organising system, similar to plant meristems. In contrast to complex plant meristems, we were unable to correlate the plant morphogen auxin with bud positioning in Sargassum, nor could we predict cell wall softening at new bud sites. Our data suggests that in Sargassum muticum there is no connection between phyllotaxis and the apical cell division pattern indicating a position-dependent patterning mechanism may be in place. The underlying mechanisms behind the phyllotactic patterning appear to be distinct from those seen in plants.