Arabidopsis (Arabidopsis thaliana) plants can produce photosynthetic tissue with active chloroplasts at temperatures as low as 4°C, and this process depends on the presence of the nuclear-encoded, chloroplast-localized RNA-binding protein CP29A. In this study, we demonstrate that CP29A undergoes phase separation in vitro and in vivo in a temperature-dependent manner, which is mediated by a prion-like domain (PLD) located between the two RNA recognition motif (RRM) domains of CP29A. The resulting droplets display liquid-like properties and are found near chloroplast nucleoids. The PLD is required to support chloroplast RNA splicing and translation in cold-treated tissue. Together, our findings suggest that plant chloroplast gene expression is compartmentalized by inducible condensation of CP29A at low temperatures, a mechanism that could play a crucial role in plant cold resistance.

中文翻译：

---

拟南芥冷驯化期间的相分离和叶绿体 RNA 加工需要类朊病毒结构域


拟南芥 (Arabidopsis thaliana) 植物可以在低至 4°C 的温度下产生具有活性叶绿体的光合组织，这一过程取决于核编码、叶绿体定位的 RNA 结合蛋白 CP29A 的存在。在这项研究中，我们证明了 CP29A 在体外和体内以温度依赖性方式经历相分离，这是由位于 CP29A 的两个 RNA 识别基序 (RRM) 结构域之间的朊病毒样结构域 (PLD) 介导的。产生的液滴显示出类似液体的特性，并且在叶绿体核附近被发现。 PLD 需要支持冷处理组织中叶绿体 RNA 剪接和翻译。总之，我们的研究结果表明，植物叶绿体基因表达是通过低温下 CP29A 的诱导缩合来划分的，这种机制可能在植物抗寒性中发挥关键作用。