The flowering plant life cycle is completed by an alternation of diploid and haploid generations. The diploid sporophytes produce initial cells that undergo meiosis and produce spores. From haploid spores, male or female gametophytes, which produce gametes, develop. The union of gametes at fertilization restores diploidy in the zygote that initiates a new cycle of diploid sporophyte development. During this complex process, cell fate determination occurs at each of the critical stages and necessarily underpins successful plant reproduction. Here, we summarize available knowledge on the regulatory mechanism of cell fate determination at these critical stages of sexual reproduction, including sporogenesis, gametogenesis, and early embryogenesis, with particular emphasis on regulatory pathways of both male and female gametes before fertilization, and both apical and basal cell lineages of a proembryo after fertilization. Investigations reveal that cell fate determination involves multiple regulatory factors, such as positional information, differential distribution of cell fate determinants, cell-to-cell communication, and cell type-specific transcription factors. These factors temporally and spatially act for different cell type differentiation to ensure successful sexual reproduction. These new insights into regulatory mechanisms underlying sexual cell fate determination not only updates our knowledge on sexual plant reproduction, but also provides new ideas and tools for crop breeding.

中文翻译：

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植物有性繁殖过程中的细胞命运决定


开花植物的生命周期由二倍体和单倍体世代的交替完成。二倍体孢子体产生初始细胞，这些细胞经历减数分裂并产生孢子。从单倍体孢子中，产生配子的雄性或雌性配子体发育出来。配子在受精时的结合恢复了受精卵中的二倍体，从而启动了二倍体孢子体发育的新周期。在这个复杂的过程中，细胞命运的决定发生在每个关键阶段，并且必须为植物的成功繁殖奠定基础。在这里，我们总结了关于有性生殖这些关键阶段细胞命运决定的调控机制的现有知识，包括孢子发生、配子发生和早期胚胎发生，特别强调受精前雄性和雌性配子的调控途径，以及受精后前胚的顶端和基底细胞谱系。研究表明，细胞命运决定涉及多种调控因素，例如位置信息、细胞命运决定因素的差异分布、细胞间通讯和细胞类型特异性转录因子。这些因素在时间和空间上作用于不同的细胞类型分化，以确保成功的有性繁殖。这些对性细胞命运决定的调控机制的新见解不仅更新了我们对有性植物繁殖的知识，也为作物育种提供了新的思路和工具。