DRN facilitates WUS transcriptional regulatory activity by chromatin remodeling to regulate shoot stem cell homeostasis in Arabidopsis

Shoot stem cells, harbored in the shoot apical meristem (SAM), play key roles during post-embryonic development of Arabidopsis and function as the origin of plant aerial tissues. Multiple transcription factors are involved in the sophisticated transcriptional regulation of stem cell homeostasis, with the WUSCHEL (WUS)/CLAVATA3 (CLV3) negative feedback loop playing a central role. WUS acts as a master regulator in maintaining stem cells through its transcriptional regulatory activity including repressive and activating abilities. Although the interaction between WUS and TOPLESS confers the repressive activity of WUS in transcriptional control, the mechanism by which WUS activates gene expression remains elusive. Here, we showed that DORNR & Ouml;SCHEN competitively interacts with WUS and disturbs the WUS homodimer, which recruits BRAHMA to activate CLV3 expression via nucleosome depletion for maintaining the stem cell pool.