Light and temperature in plants are perceived by a common receptor, phytochrome B (phyB). How phyB distinguishes these signals remains elusive. Here, we report that phyB spontaneously undergoes phase separation to assemble liquid-like droplets. This capacity is driven by its C terminus through self-association, whereas the intrinsically disordered N-terminal extension (NTE) functions as a biophysical modulator of phase separation. Light exposure triggers a conformational change to subsequently alter phyB condensate assembly, while temperature sensation is directly mediated by the NTE to modulate the phase behavior of phyB droplets. Multiple signaling components are selectively incorporated into phyB droplets to form concentrated microreactors, allowing switch-like control of phyB signaling activity through phase transitions. Therefore, light and temperature cues are separately read out by phyB via allosteric changes and spontaneous phase separation, respectively. We provide a conceptual framework showing how the distinct but highly correlated physical signals are interpreted and sorted by one receptor.

植物中的光和温度由共同的受体光敏色素 B (phyB) 感知。phyB 如何区分这些信号仍然难以捉摸。在这里，我们报告 phyB 自发地经历相分离以组装液体状液滴。这种能力是由其 C 端通过自缔合驱动的，而本质上无序的 N 端延伸 (NTE) 则作为相分离的生物物理调节剂发挥作用。光照会触发构象变化，随后改变 phyB 凝聚物的组装，而温度感觉由 NTE 直接介导，以调节 phyB 液滴的相行为。多种信号成分选择性地结合到 phyB 液滴中以形成浓缩的微反应器，从而允许通过相变对 phyB 信号传导活动进行类似开关的控制。所以，phyB 分别通过变构变化和自发相分离分别读出光和温度线索。我们提供了一个概念框架，展示了不同但高度相关的物理信号如何被一个受体解释和分类。