The Biophysics of Pattern Formation in Plants

本文研究了植物芽部花纹的表达机制。目的是解释a)模式的起源，b)其繁殖，即叶状性，以及c)花突变体中模式的变化。器官模式首先见于顶穹窿（被膜）表层的褶皱或凸起的排列。目前的理论通常假设化学预模式首先由扩散抑制剂或形态形成因子产生，然后一致地转化为固体组织结构。本文提出进一步追求另一种假设，即基于von Karman方程的屈曲理论，即根据固体物理规律直接在组织本身中产生图案。研究计划如下：选定的发育过程将通过非破坏性扫描电镜复制技术进行表征，以确定体内组织折叠和细胞生长的精确过程。平行计算机模拟将确定屈曲理论在多大程度上可以解释观测到的递进。格林博士将研究营养芽和形态花突变体（矮牵牛同心圆和盲）。进一步的测试包括对物理约束的反应和形态活性化合物的局部应用。本研究将阐明形态发生的生物物理学及其在扩散剂作用下的调节作用。＊＊＊

9304369 Green This proposal addresses the mechanisms for expression of pattern in the plant shoot. The aim is to explain a) the origin of pattern, b) its propagation, i.e. phyllotaxis, and c) change of pattern as in flower mutants. Organ pattern is first seen in the arrangement of folds or bumps in the surface layer of the apical dome, the tunica. Current theory usually postulates that a chemical pre-pattern is first generated by diffusing inhibitors or morphogens and then converted, congruently, to solid tissue configuration. It is proposed here to further pursue an alternate hypothesis where pattern is directly generated in the tissue itself by physical laws of the solid state, i.e. buckling theory based on the von Karman equations. The research plan is as follows: Selected developmental progressions will be characterized by a non-destructive SEM replica technique to determine the precise course of tissue folding and cell growth in vivo. Parallel computer simulations will determine the extent to which buckling theory can account for the observed progressions. Dr. Green will study vegetative shoots and morphological floral mutants (concentric and blind in Petunia). Further testing involves responses to physical constraint and the local application of morphogenetically active compounds. This research will clarify the biophysics of morphogenesis and its modulation by diffusing agents. ***