An R2R3-type transcription factor gene AtMYB59 regulates root growth and cell cycle progression in Arabidopsis

作者：Mu Rui Ling; Cao Yang Rong; Liu Yun Feng; Lei Gang; Zou Hong Feng; Liao Yong; Wang Hui Wen; Zhang Wan Ke; Ma Biao; Du Ji Zhou; Yuan Ming; Zhang Jin Song^*; Chen Shou Yi

来源：Cell Research, 2009, 19(11): 1291-1304.

DOI：10.1038/cr.2009.83

• MYB protein
• transcription factor
• cell cycle
• root growth

MYB proteins play important roles in eukaryotic organisms. In plants, the R1R2R3-type MYB proteins function in cell cycle control. However, whether the R2R3-type MYB protein is also involved in the cell division process remains unknown. Here, we report that an R2R3-type transcription factor gene, AtMYB59, is involved in the regulation of cell cycle progression and root growth. The AtMYB59 protein is localized in the nuclei of onion epidermal cells and has transactivation activity. Expression of AtMYB59 in yeast cells suppresses cell proliferation, and the transformants have more nuclei and higher aneuploid DNA content with longer cells. Mutation in the conserved domain of AtMYB59 abolishes its effects on yeast cell growth. In synchronized Arabidopsis cell suspensions, the AtMYB59 gene is specifically expressed in the S phase during cell cycle progression. Expression and promoter-GUS analysis reveals that the AtMYB59 gene is abundantly expressed in roots. Transgenic plants overexpressing AtMYB59 have shorter roots compared with wild-type plants (Arabidopsis accession Col-0), and around half of the mitotic cells in root tips are at metaphase. Conversely, the null mutant myb59-1 has longer roots and fewer mitotic cells at metaphase than Col, suggesting that AtMYB59 may inhibit root growth by extending the metaphase of mitotic cells. AtMYB59 regulates many downstream genes, including the CYCB1; 1 gene, probably through binding to MYB-responsive elements. These results support a role for AtMYB59 in cell cycle regulation and plant root growth.

• 出版日期2009-11
• 单位中国科学院遗传与发育生物学研究所; 中国农业大学