Coen Olivier, Lu Jing, Xu Wenjia, Pateyron Stéphanie, Grain Damaris, Péchoux Christine, Lepiniec Loïc, Magnani Enrico
Institut Jean-Pierre Bourgin, INRA, AgroParisTech, CNRS, University of Paris-Saclay, Versailles, France.
École Doctorale 567 Sciences du Végétal, University Paris-Sud, University of Paris-Saclay, Orsay, France.
Front Plant Sci. 2020 Feb 6;10:1801. doi: 10.3389/fpls.2019.01801. eCollection 2019.
Seeds have greatly contributed to the successful colonization of land by plants. Compared to spores, seeds carry nutrients, rely less on water for germination, provide a higher degree of protection against biotic and abiotic stresses, and can disperse in different ways. Such advantages are, to a great extent, provided by the seed coat. The evolution of a multi-function seed-coat is inheritably linked to the evolution of tissue polarity, which allows the development of morphologically and functionally distinct domains. Here, we show that the endothelium, the innermost cell layer of the seed coat, displays distinct morphological features along the proximal-distal axis. Furthermore, we identified a TRANSPARENT TESTA transcriptional module that contributes to establishing endothelium polarity and responsiveness to fertilization. Finally, we characterized its downstream gene pathway by whole-genome transcriptional analyses. We speculate that such a regulatory module might have been responsible for the evolution of morphological diversity in seed shape, micropylar pore formation, and cuticle deposition.
种子对植物成功在陆地上定殖做出了巨大贡献。与孢子相比，种子携带营养物质，发芽对水的依赖较少，对生物和非生物胁迫具有更高程度的保护，并且可以以不同方式传播。这些优势在很大程度上由种皮提供。多功能种皮的进化与组织极性的进化内在相关，组织极性允许形态和功能不同的区域发育。在这里，我们表明，种皮最内层的细胞层——内珠被，沿近远轴显示出明显的形态特征。此外，我们鉴定了一个透明种皮转录模块，该模块有助于建立内珠被极性和对受精的反应。最后，我们通过全基因组转录分析对其下游基因途径进行了表征。我们推测，这样一个调控模块可能是种子形状、珠孔形成和角质层沉积形态多样性进化的原因。
