Dresselhaus Thomas, Sprunck Stefanie, Wessel Gary M
Cell Biology and Plant Biochemistry, Biochemie-Zentrum Regensburg, University of Regensburg, 93040 Regensburg, Germany.
Cell Biology and Plant Biochemistry, Biochemie-Zentrum Regensburg, University of Regensburg, 93040 Regensburg, Germany.
Curr Biol. 2016 Feb 8;26(3):R125-39. doi: 10.1016/j.cub.2015.12.032.
Compared with the animal kingdom, fertilization is particularly complex in flowering plants (angiosperms). Sperm cells of angiosperms have lost their motility and require transportation as a passive cargo by the pollen tube cell to the egg apparatus (egg cell and accessory synergid cells). Sperm cell release from the pollen tube occurs after intensive communication between the pollen tube cell and the receptive synergid, culminating in the lysis of both interaction partners. Following release of the two sperm cells, they interact and fuse with two dimorphic female gametes (the egg and the central cell) forming the major seed components embryo and endosperm, respectively. This process is known as double fertilization. Here, we review the current understanding of the processes of sperm cell reception, gamete interaction, their pre-fertilization activation and fusion, as well as the mechanisms plants use to prevent the fusion of egg cells with multiple sperm cells. The role of Ca(2+) is highlighted in these various processes and comparisons are drawn between fertilization mechanisms in flowering plants and other eukaryotes, including mammals.
与动物界相比，开花植物（被子植物）的受精过程尤为复杂。被子植物的精细胞已失去运动能力，需要作为被动货物由花粉管细胞运输至卵细胞器（卵细胞和辅助助细胞）。花粉管中的精细胞释放发生在花粉管细胞与接受性助细胞之间的密集通讯之后，最终导致两个相互作用伙伴的裂解。释放出两个精细胞后，它们与两个不同形态的雌配子（卵细胞和中央细胞）相互作用并融合，分别形成种子的主要成分胚和胚乳。这个过程称为双受精。在这里，我们综述了目前对精细胞接受、配子相互作用、受精前激活和融合过程的理解，以及植物用于防止卵细胞与多个精细胞融合的机制。钙（Ca2+）在这些不同过程中的作用得到了强调，并对开花植物与包括哺乳动物在内的其他真核生物的受精机制进行了比较。
