ORIGINAL ARTICLE Cell Research (2007): 815-828 AtCDC5 regulates the G2 to M transition of the cell cycle and is critical for the function of Arabidopsis shoot apical meristemZhiqiang Lin1, Kangquan Yin1, Danling Zhu1, Zhangliang Chen1,2, Hongya Gu1,2 and Li-Jia Qu1,2 1National Laboratory for Protein Engineering and Plant Genetic Engineering, Peking-Yale Joint Research Center for Plant Molecular Genetics and AgroBiotechnology, College of Life Sciences, Peking University, Beijing 100871, China2The National Plant Gene Research Center (Beijing), Beijing 100101, China
As a cell cycle regulator, the Myb-related CDC5 protein was reported to be essential for the G2 phase of the cell cycle in yeast and animals, but little is known about its function in plants. Here we report the functional characterization of the CDC5 gene in Arabidopsis thaliana. Arabidopsis CDC5 (AtCDC5) is mainly expressed in tissues with high cell division activity, and is expressed throughout the entire process of embryo formation. The AtCDC5 loss-of-function mutant is embryonic lethal. In order to investigate the function of AtCDC5 in vivo, we generated AtCDC5-RNAi plants in which the expression of AtCDC5 was reduced by RNA interference. We found that the G2 to M (G2/M) phase transition was affected in the AtCDC5-RNAi plants, and that endoreduplication was increased. Additionally, the maintenance of shoot apical meristem (SAM) function was disturbed in the AtCDC5-RNAi plants, in which both the WUSCHEL (WUS)-CLAVATA (CLV) and the SHOOT MERISTEMLESS (STM) pathways were impaired. In situ hybridization analysis showed that the expression of STM was greatly reduced in the shoot apical cells of the AtCDC5-RNAi plants. Moreover, cyclinB1 or Histone4 was found to be expressed in some of these cells when the transcript of STM was undetectable. These results suggest that AtCDC5 is essential for the G2/M phase transition and may regulate the function of SAM by controlling the expression of STM and WUS. Cell Research (2007) 17:815–828. doi: 10.1038/cr.2007.71; published online 4 September 2007 Keywords: AtCDC5, G2/M phase transition, shoot apical meristems, WUS, STM |
copyright©2006 Institute of Biochemistry and Cell Biology,SIBS,CAS
ISSN:1001-0602(Print),1748-7838(Online);CN:31-1568
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