Polevova Svetlana V, Grigorjeva Valentina V, Gabarayeva Nina I
Department of Biology, Moscow State University, Leninski Gory, 1, 119991, Moscow, Russia.
Komarov Botanical Institute of Russian Academy of Sciences, Popov st. 2, 197376, St. Petersburg, Russia.
Protoplasma. 2023 Jan;260(1):281-298. doi: 10.1007/s00709-022-01777-8. Epub 2022 Jun 3.
Our aim was to unravel the underlying mechanisms of pollen wall development in Cymbalaria muralis. By determining the sequence of developing substructures with TEM, we intended to compare it with that of other taxa and clarify whether physical processes of self-assembly and phase separation were involved. In parallel, we tried to simulate in vitro the substructures observed in Cymbalaria muralis exine development, using colloidal mixtures, to determine whether purely physical self-assembly processes could replicate them. Exine ontogeny followed the main stages observed in many other species and was initiated by phase separation, resulting in heterogeneity of the homogeneous contents of the periplasmic space around the microspore which is filled with genome-determined substances. At every stage, phase separation and self-assembly come into force, gradually driving the substances through the sequence of mesophases: spherical micelles, columns of spherical micelles, cylindrical micelles arranged in a layer, laminate micelles. The final two of these mesophases define the structure of the columellate ectexine and lamellate endexine respectively. Structures obtained in vitro from colloidal mixtures simulated the developing exine structures. Striking columella-like surface of some abnormal tapetal cells and lamella-like structures in the anther medium confirm the conclusion that pattern generation is a feature of colloidal materials, after genomic control on material contents. Simulation experiments show the high pattern-generating capacity of colloidal interactions.
我们的目标是揭示墙草（Cymbalaria muralis）花粉壁发育的潜在机制。通过透射电子显微镜（TEM）确定发育中的亚结构序列，我们旨在将其与其他分类群的序列进行比较，并阐明是否涉及自组装和相分离的物理过程。同时，我们尝试使用胶体混合物在体外模拟墙草外壁发育过程中观察到的亚结构，以确定纯粹的物理自组装过程是否能够复制它们。外壁个体发育遵循许多其他物种中观察到的主要阶段，由相分离引发，导致充满基因组决定物质的小孢子周围周质空间均匀内容物的异质性。在每个阶段，相分离和自组装开始起作用，逐渐驱动物质通过中间相序列：球形胶束、球形胶束柱、排列成层的圆柱形胶束、层状胶束。这些中间相的最后两个分别定义了柱状外壁和层状内壁的结构。从胶体混合物中体外获得的结构模拟了发育中的外壁结构。一些异常绒毡层细胞的显著柱状表面和花药培养基中的层状结构证实了这样的结论：在对物质含量进行基因组控制后，图案生成是胶体材料的一个特征。模拟实验表明胶体相互作用具有很高的图案生成能力。
