RIKEN Plant Science Center, 1-7-22 Suehiro-cho, Tsurumi, Yokohama, Kanagawa, 230-0045, Japan.
Curr Opin Plant Biol. 2010 Dec;13(6):654-60. doi: 10.1016/j.pbi.2010.10.006. Epub 2010 Nov 18.
Timely progression of the mitotic cell cycle is central for growth and development of plant organs. Many cell types in plants also enter an alternative cell cycle called the endoreduplication cycle or endocycle in which cells increase their ploidy through repeated rounds of chromosomal replication without cell divisions. The transition from the mitotic cycle into the endocycle often coincides with the initiation of cell expansion and cell differentiation, and strong correlations between final ploidy level and cell size have been reported in many plant species. Recent studies have begun to unveil how developmental signals modulate entry and exit of the endocycle through both transcriptional and post-transcriptional mechanisms. An increase in ploidy by endocycles is not an ultimate determinant of plant cell size and it is likely that it sets the maximum capacity for future cellular growth.
有丝分裂细胞周期的适时进展是植物器官生长和发育的核心。植物中的许多细胞类型也会进入另一种细胞周期，称为内复制周期或内周期，在此过程中，细胞通过多次染色体复制而不进行细胞分裂来增加其倍性。有丝分裂周期向内周期的转变通常与细胞扩张和细胞分化的开始相吻合，并且在许多植物物种中已经报道了最终倍性水平与细胞大小之间的强相关性。最近的研究开始揭示发育信号如何通过转录和转录后机制来调节内周期的进入和退出。内周期的倍性增加并不是植物细胞大小的最终决定因素，它可能为未来的细胞生长设定了最大容量。
