银杏(GinkgobilobaL.)是种子植物系统发育中最早存在的物种之一。胚胎发育模式可以为起源提供基本证据,进化,和种子的适应。然而,银杏胚胎发生过程中的建筑和形态动力学(G.biloba)仍然难以捉摸。在这里,我们使用显微计算机断层扫描成像和改进的染色方法,从胚胎发育的三个阶段获得了超过2200个视觉切片.基于三维时空模式分析,我们发现一个茎尖分生组织有七个高度分化的叶原基,包括顶端和腋生叶芽,存在于成熟的银杏胚胎中。从正面进行3D渲染,top,侧视图显示了位于下胚轴和子叶中的两个单独的气管运输系统,代表胚胎发生的独特模式。此外,分泌腔的形态动态分析表明,它们在发育过程中与子叶密切相关。此外,我们鉴定了基因GbLBD25a(横向器官边界域25a),GbCESA2a(纤维素合酶2a),GbMYB74c(成髓细胞病74c),GbPIN2(PIN-FORMED2)与血管发育调节相关,和GbWRKY1(WRKYGOK1),GbbHLH12a(基本螺旋-环-螺旋12a),GbJAZ4(茉莉酸zim结构域4)可能参与分泌腔的形成。此外,我们发现,黄酮类化合物在成熟胚胎中的积累可以促进发芽后的生长和在恶劣环境下的幼苗建立。我们的3D空间重建技术与多组学分析相结合,为研究胚胎发育过程中的发育结构和分子机制开辟了途径,并为胚胎发育和成熟的进化研究奠定了基础。
Ginkgo (Ginkgo biloba L.) is one of the earliest extant species in seed plant phylogeny. Embryo development patterns can provide fundamental evidence for the origin, evolution, and adaptation of seeds. However, the architectural and morphological dynamics during
embryogenesis in Ginkgo biloba (G. biloba) remain elusive. Herein, we obtained over 2200 visual slices from three stages of embryo development using micro-computed tomography imaging with improved staining methods. Based on 3D spatio-temporal pattern analysis, we found that a shoot apical meristem with seven highly differentiated leaf primordia, including apical and axillary leaf buds, is present in mature Ginkgo embryos. 3D rendering from the front, top, and side views showed two separate transport systems of tracheids located in the hypocotyl and cotyledon, representing a unique pattern of
embryogenesis. Furthermore, the morphological dynamic analysis of secretory cavities indicated their strong association with cotyledons during development. In addition, we identified genes GbLBD25a (lateral organ boundaries domain 25a), GbCESA2a (cellulose synthase 2a), GbMYB74c (myeloblastosis 74c), GbPIN2 (PIN-FORMED 2) associated with vascular development regulation, and GbWRKY1 (WRKYGOK 1), GbbHLH12a (basic helix-loop-helix 12a), GbJAZ4 (jasmonate zim-domain 4) potentially involved in the formation of secretory cavities. Moreover, we found that flavonoid accumulation in mature embryos could enhance post-germinative growth and seedling establishment in harsh environments. Our 3D spatial reconstruction technique combined with multi-omics analysis opens avenues for investigating developmental architecture and molecular mechanisms during
embryogenesis and lays the foundation for evolutionary studies of embryo development and maturation.