Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN, 47907, USA.
Purdue Center for Plant Biology, Purdue University, West Lafayette, IN, 47907, USA.
Commun Biol. 2022 Jul 1;5(1):650. doi: 10.1038/s42003-022-03627-y.
Fern gametophytes are autotrophic and independent of sporophytes, and they develop pluripotent meristems that drive prothallus development and sexual reproduction. To reveal cellular dynamics during meristem development in fern gametophytes, we performed long-term time-lapse imaging and determined the real-time lineage, identity and division activity of each single cell from meristem initiation to establishment in gametophytes of the fern Ceratopteris richardii. Our results demonstrate that in Ceratopteris gametophytes, only a few cell lineages originated from the marginal layer contribute to meristem initiation and proliferation, and the meristem lacks a distinguishable central zone or apical cell with low division activity. Within the meristem, cell division is independent of cell lineages and cells at the marginal layer are more actively dividing than inner cells. Furthermore, the meristem triggers differentiation of adjacent cells into egg-producing archegonia in a position-dependent manner. These findings advance the understanding of diversified meristem and gametophyte development in land plants.
蕨类植物的配子体是自养的，不依赖于孢子体，它们发育出多能性的分生组织，驱动原叶体的发育和有性繁殖。为了揭示蕨类植物配子体分生组织发育过程中的细胞动态，我们对蕨类植物凤尾蕨属的配子体进行了长时间延时成像，并从分生组织起始到建立阶段确定了每个单个细胞的实时谱系、身份和分裂活性。我们的结果表明，在凤尾蕨属的配子体中，只有少数起源于边缘层的细胞谱系对分生组织的起始和增殖有贡献，而且该分生组织缺乏可区分的中央区或具有低分裂活性的顶细胞。在分生组织内，细胞分裂独立于细胞谱系，边缘层的细胞比内层细胞分裂更为活跃。此外，分生组织以位置依赖的方式触发相邻细胞分化为产卵子的颈卵器。这些发现推进了对陆地植物多样化的分生组织和配子体发育的理解。
