Journal Article

A hierarchical transcriptional network activates specific CDK inhibitors that regulate G2 to control cell size and number in Arabidopsis

Breuer, Christian, Benhamed, Moussa, Maeo, Kenichiro, Bögre, László, Yamada, Kesuke, Suzuki, Toshiya, Ishida, Takashi, An, Jing, Magyar, Zoltán, Takatsuka, Hirotomo, Ito, Masaki, Sugimoto, Keiko, Latrasse, David, Imamura, Miyu, Nomoto, Yuji, Suzuki, Takamasa, Yamashino, Takafumi, Gombos, Magdolna, Huang, Ying, Raynaud, Cécile

2022

Overview

How cell size and number are determined during organ development remains a fundamental question in cell biology. Here, we identified a GRAS family transcription factor, called SCARECROW-LIKE28 (SCL28), with a critical role in determining cell size in Arabidopsis. SCL28 is part of a transcriptional regulatory network downstream of the central MYB3Rs that regulate G2 to M phase cell cycle transition. We show that SCL28 forms a dimer with the AP2-type transcription factor, AtSMOS1, which defines the specificity for promoter binding and directly activates transcription of a specific set of SIAMESE-RELATED (SMR) family genes, encoding plant-specific inhibitors of cyclin-dependent kinases and thus inhibiting cell cycle progression at G2 and promoting the onset of endoreplication. Through this dose-dependent regulation of SMR transcription, SCL28 quantitatively sets the balance between cell size and number without dramatically changing final organ size. We propose that this hierarchical transcriptional network constitutes a cell cycle regulatory mechanism that allows to adjust cell size and number to attain robust organ growth. Cell division and expansion are carefully coordinated during organ growth. Here, the authors show that the SCL28 and SMOS1 transcription factors interact to regulate cyclin-dependent kinase inhibitors and promote cell size increase over division in Arabidopsis.

• Publisher: Nature Publishing Group UK,Nature Publishing Group,Nature Portfolio
• Subject: 14/19 / 38/109 / 38/111 / 38/23 / 38/39 / 38/77 / 38/88 / 45/15 / 45/23 / 45/91 / 631/449/1659 / 631/449/2653 / 631/449/448/1358 / Arabidopsis / Arabidopsis - genetics / Arabidopsis - metabolism / Arabidopsis Proteins - genetics / Arabidopsis Proteins - metabolism / Cell cycle / Cell Cycle - genetics / Cell division / Cell Size / Chemical Sciences / Cyclin-dependent kinase / Cyclin-dependent kinase inhibitors / Cyclin-dependent kinases / Dimers / Gene regulation / Gene Regulatory Networks / Humanities and Social Sciences / Inhibitors / Kinases / Life Sciences / multidisciplinary / Regulatory mechanisms (biology) / Science / Science (multidisciplinary) / Transcription factors / Transcription Factors - metabolism