背景回顾：Osmotic stress imposed by drought and high salinity inhibits plant growth and crop yield. 

提出问题：However, our current knowledge on the mechanism by which plants sense osmotic stress is still limited. 

主要发现：Here, we identify the transcriptional regulator SEUSS (SEU) as a key player in hyperosmotic stress response in Arabidopsis. 

结果1-SEU响应渗透胁迫发生凝聚：SEU rapidly coalesces into liquid-like nuclear condensates when extracellular osmolarity increases. 

结果2-IDR1作用于SEU的凝聚：The intrinsically disordered region 1 (IDR1) of SEU is responsible for its condensation. IDR1 undergoes conformational changes to adopt more compact states after an increase in molecular crowding both in vitro and in cells, and two predicted α-helical peptides are required. 

结果3-SEU凝聚作用于渗透胁迫响应：SEUcondensation is indispensable for osmotic stress tolerance, and loss of SEU dramatically compromises the expression of stress tolerance genes. 

结论：Our work uncovers a critical role of biomolecular condensates in cellular stress perception and response and expands our understanding of the osmotic stress pathway.

SEU作用于拟南芥的渗透胁迫耐受性

干旱和高盐所导致的渗透胁迫抑制了植物生长和作物产量。然而，目前我们对植物感知渗透胁迫的机制仍了解有限。本文中，作者在拟南芥中鉴定到了一个高渗胁迫响应关键的转录调控因子SEUSS。当胞外的渗透压增加时，SEU能够快速凝聚成类似液态的核凝聚体。SEU蛋白的IDR1区域作用于其凝聚属性。无论是在体外，还是在细胞内，当分子拥挤程度增加后，IDR1会经历构像变化以进入更加紧凑的状态，而这一改变需要其中的两个α-螺旋肽。SEU凝聚对于渗透胁迫耐受性是必不可少的，SEU缺陷会导致胁迫耐受性基因的表达受到剧烈影响。本文的研究结果揭示了一个生物分子凝聚的重要作用，其在细胞水平感知并响应胁迫，拓宽了我们对于渗透胁迫途径的理解。

** 方晓峰 **