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

Archive ouverte

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

Edité par CCSD ; Nature Publishing Group -

International audience. Abstract 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.

• Description
• Sujet/Public
• Outil
• Outil d'anticipation
• Mémoire et thèse
• Gestion