Department of Biological Sciences, Faculty of Science, Hokkaido University, Sapporo, Hokkaido 060-0810, Japan.
Graduate School of Life Sciences, Tohoku University, Aoba-ku, Sendai 980-8577, Japan.
Plant Cell. 2022 Jan 20;34(1):228-246. doi: 10.1093/plcell/koab218.
Bryophytes are nonvascular spore-forming plants. Unlike in flowering plants, the gametophyte (haploid) generation of bryophytes dominates the sporophyte (diploid) generation. A comparison of bryophytes with flowering plants allows us to answer some fundamental questions raised in evolutionary cell and developmental biology. The moss Physcomitrium patens was the first bryophyte with a sequenced genome. Many cell and developmental studies have been conducted in this species using gene targeting by homologous recombination. The liverwort Marchantia polymorpha has recently emerged as an excellent model system with low genomic redundancy in most of its regulatory pathways. With the development of molecular genetic tools such as efficient genome editing, both P. patens and M. polymorpha have provided many valuable insights. Here, we review these advances with a special focus on polarity formation at the cell and tissue levels. We examine current knowledge regarding the cellular mechanisms of polarized cell elongation and cell division, including symmetric and asymmetric cell division. We also examine the role of polar auxin transport in mosses and liverworts. Finally, we discuss the future of evolutionary cell and developmental biological studies in plants.
苔藓植物是无维管束的孢子形成植物。与开花植物不同，苔藓植物的配子体（单倍体）世代占优势于孢子体（二倍体）世代。将苔藓植物与开花植物进行比较，可以帮助我们回答进化细胞和发育生物学中提出的一些基本问题。藓纲植物Physcomitrium patens 是第一个基因组测序的苔藓植物。使用同源重组的基因靶向技术，在该物种中进行了许多细胞和发育研究。地钱 Marchantia polymorpha 最近成为一个优秀的模式系统，其大多数调控途径的基因组冗余度较低。随着分子遗传工具（如高效的基因组编辑）的发展，P. patens 和 M. polymorpha 都提供了许多有价值的见解。在这里，我们特别关注细胞和组织水平的极性形成，回顾这些进展。我们检查了关于极化细胞伸长和细胞分裂的细胞机制的现有知识，包括对称和不对称细胞分裂。我们还研究了极性生长素运输在苔藓植物和地钱中的作用。最后，我们讨论了植物进化细胞和发育生物学研究的未来。
