The Arabidopsis D-type cyclin CYCD4 controls cell division in the stomatal lineage of the hypocotyl epidermis
The Arabidopsis D-type cyclin CYCD4 controls cell division in the stomatal lineage of the hypocotyl epidermis
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DOI：
10.1105/tpc.106.046763
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发表时间：
2007-04-01
期刊：
影响因子：
11.6
通讯作者：
Umeda, Masaaki
中科院分区：
文献类型：
--
作者：
Kono, Atsushi;Umeda-Hara, Chikage;Umeda, Masaaki
细胞周期蛋白D （Cyclin D， CYCD）在细胞周期进程和响应外部信号的再进入过程中起着重要作用。在这里，我们证明拟南芥CYCD4与下胚轴的特定细胞分裂有关。我们观察到cycd4 T-DNA插入突变体在下胚轴表皮的非突出细胞和气孔数量减少。相反，CYCD4过表达促进了野生型植物下胚轴上部非突出细胞群的细胞分裂，而下胚轴上部通常是气孔形成的地方。过度增殖的细胞属于气孔系，表现为TOO MANY mouth基因的表达，但与分生组织不同的是，大多数细胞不是三角形的。虽然植物激素赤霉素促进了下胚轴的气孔分化，但抑制赤霉素的生物合成并不能阻止CYCD4诱导细胞分裂。这些结果表明，CYCD4在气孔谱系祖细胞的增殖中起特殊作用，而不是在气孔分化中起特殊作用。我们认为CYCD4在下胚轴气孔形成的初始阶段控制细胞分裂。
Cyclin D (CYCD) plays an important role in cell cycle progression and reentry in response to external signals. Here, we demonstrate that Arabidopsis thaliana CYCD4 is associated with specific cell divisions in the hypocotyl. We observed that cycd4 T-DNA insertion mutants had a reduced number of nonprotruding cells and stomata in the hypocotyl epidermis. Conversely, CYCD4 overexpression enhanced cell division in nonprotruding cell files in the upper region of the hypocotyls, where stomata are usually formed in wild-type plants. The overproliferative cells were of stomatal lineage, which is marked by the expression of the TOO MANY MOUTHS gene, but unlike the meristemoids, most of them were not triangular. Although the phytohormone gibberellin promoted stomatal differentiation in the hypocotyl, inhibition of gibberellin biosynthesis did not prevent CYCD4 from inducing cell division. These results suggested that CYCD4 has a specialized function in the proliferation of stomatal lineage progenitors rather than in stomatal differentiation. We propose that CYCD4 controls cell division in the initial step of stomata formation in the hypocotyl.