Yu Zhang, Bingchen Li, Yu Chen, Jiawei Li, Yao Wang, Tiantian Ye, Ying Ye, Zhiwei Liu, Zhiyue Feng, Stephanie Hutin, Shaoli Zhou, Jianping Guo, Ruihui Zhang, Zhu Liu, Faming Dong, Haiyan Xiong, Chloe Zubieta, Lizhong Xiong*, Xuelei Lai*

The EMBO Journal, Published: 06 July 2026

Abstract

Transcriptional repression is a central mechanism regulating plant growth and development, yet how plant-specific corepressors achieve robust gene silencing remains unclear. Here, we identify the rice corepressor TPR2 (TOPLESS-RELATED 2) as a phase-separating protein that forms nuclear condensates through the cooperative action of an intrinsically disordered region (IDR1) and a plant-specific N-terminal tetramerization domain. Structure-guided mutagenesis disrupting tetramerization or deleting IDR1 markedly impaired condensate formation in vivo and in vitro. Complementation assays showed that only full-length TPR2, capable of robust condensate formation, rescued the growth defects of the tpr2 mutant, whereas phase separation-deficient variants failed to do so. Mechanistically, we demonstrate that TPR2 co-condenses with repressors such as D53 and IAA3 to facilitate histone deacetylation and establish repressive chromatin states in a phase separation-dependent manner, thereby fine-tuning key developmental genes. Together, these findings define a condensate-based mechanism for transcriptional repression in plants, linking corepressor phase separation to chromatin modification, gene silencing and developmental control.

论文链接：https://link.springer.com/article/10.1038/s44318-026-00852-7