Department of Plant Systems Biology, VIB, Ghent, Belgium.
EMBO J. 2011 Jul 19;30(16):3430-41. doi: 10.1038/emboj.2011.240.
In multicellular organisms, morphogenesis relies on a strict coordination in time and space of cell proliferation and differentiation. In contrast to animals, plant development displays continuous organ formation and adaptive growth responses during their lifespan relying on a tight coordination of cell proliferation. How developmental signals interact with the plant cell-cycle machinery is largely unknown. Here, we characterize plant A2-type cyclins, a small gene family of mitotic cyclins, and show how they contribute to the fine-tuning of local proliferation during plant development. Moreover, the timely repression of CYCA2;3 expression in newly formed guard cells is shown to require the stomatal transcription factors FOUR LIPS/MYB124 and MYB88, providing a direct link between developmental programming and cell-cycle exit in plants. Thus, transcriptional downregulation of CYCA2s represents a critical mechanism to coordinate proliferation during plant development.
在多细胞生物中，形态发生依赖于细胞增殖和分化在时间和空间上的严格协调。与动物不同，植物的发育在其生命周期中表现出连续的器官形成和适应性生长反应，这依赖于细胞增殖的紧密协调。发育信号如何与植物细胞周期机制相互作用在很大程度上是未知的。在这里，我们描述了植物 A2 型细胞周期蛋白，这是一个有丝分裂细胞周期蛋白的小基因家族，展示了它们如何有助于植物发育过程中局部增殖的精细调节。此外，我们还表明，在新形成的保卫细胞中，CYCA2;3 表达的适时抑制需要气孔转录因子 FOUR LIPS/MYB124 和 MYB88，这为植物中发育编程和细胞周期退出之间提供了直接联系。因此，CYCA2 的转录下调代表了协调植物发育过程中增殖的关键机制。
