Division of Molecular Biosciences, Cardiff School of Biosciences, Cardiff University, Cardiff, Wales CF10 3AX, UK.
Department of Comparative Development and Genetics, Max Planck Institute for Plant Breeding Research, 50829 Cologne, Germany.
Nat Commun. 2017 Apr 27;8:15060. doi: 10.1038/ncomms15060.
Mean cell size at division is generally constant for specific conditions and cell types, but the mechanisms coupling cell growth and cell cycle control with cell size regulation are poorly understood in intact tissues. Here we show that the continuously dividing fields of cells within the shoot apical meristem of Arabidopsis show dynamic regulation of mean cell size dependent on developmental stage, genotype and environmental signals. We show cell size at division and cell cycle length is effectively predicted using a two-stage cell cycle model linking cell growth and two sequential cyclin dependent kinase (CDK) activities, and experimental results concur in showing that progression through both G1/S and G2/M is size dependent. This work shows that cell-autonomous co-ordination of cell growth and cell division previously observed in unicellular organisms also exists in intact plant tissues, and that cell size may be an emergent rather than directly determined property of cells.
分裂时的平均细胞大小通常在特定条件和细胞类型下保持恒定，但在完整组织中，细胞生长和细胞周期调控与细胞大小调节相偶联的机制仍知之甚少。在这里，我们表明拟南芥茎尖分生组织内不断分裂的细胞区域表现出依赖于发育阶段、基因型和环境信号的平均细胞大小的动态调节。我们表明，通过连接细胞生长和两个连续的细胞周期蛋白依赖性激酶（CDK）活性的两阶段细胞周期模型，可以有效地预测分裂时的细胞大小和细胞周期长度，并且实验结果一致表明，通过 G1/S 和 G2/M 的进展都是依赖于大小的。这项工作表明，以前在单细胞生物中观察到的细胞自主协调细胞生长和细胞分裂也存在于完整的植物组织中，并且细胞大小可能是一个涌现的特性，而不是细胞的直接决定因素。
