A regulatory module controlling stress-induced cell cycle arrest in Arabidopsis (bioRxiv)

Progression of the cell cycle central to growth, but during stress conditions plants arrest cell cycle progression to enable the organism to survive. SUPPRESSOR OF GAMMA RESPONSE 1 (SOG1), a plant-specific NAC-type transcription factor, regulates the expression of almost all genes induced by double-strand breaks (DSBs) and consequently arrests the cell cycle in G2. Takahashi et al. recently identified 146 genes targeted by SOG1 and among them, two NAC transcription factors (ANAC044 and ANAC085) are close relatives of SOG1. Further evidence demonstrated that SOG1 directly induces ANAC044 and ANAC085 under DNA damage conditions and both anac044 and anac085 mutants are tolerant to DNA damage. In contrast, ANAC044 overexpression inhibits G2/M progression under DNA damage conditions. Furthermore, ANAC044 and ANAC085 control protein accumulation of the repressor-type MYB3R (R1R2R3-Myb). This work provides a comprehensive model where DNA damage and heat stress induce ANAC044 and ANAC085 to promote Rep-MYB accumulation, which repress a group of G2/M phase specific genes and consequently arrest G2. (Summary by Arif Ashraf) bioRxiv: 10.1101/495200