The unfolded protein response (UPR) of the endoplasmic reticulum constitutes a conserved and essential cytoprotective pathway designed to survive biotic and abiotic stresses that alter the proteostasis of the endoplasmic reticulum. The UPR is typically considered cell-autonomous and it is yet unclear whether it can also act systemically through non-cell autonomous signaling. We have addressed this question using a genetic approach coupled with micro-grafting and a suite of molecular reporters in the model plant species Arabidopsis thaliana. We show that the UPR has a non-cell autonomous component, and we demonstrate that this is partially mediated by the intercellular movement of the UPR transcription factor bZIP60 facilitating systemic UPR signaling. Therefore, in multicellular eukaryotes such as plants, non-cell autonomous UPR signaling relies on the systemic movement of at least a UPR transcriptional modulator.

中文翻译：

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系统信号传导有助于植物内质网的未折叠蛋白质反应。

内质网的未折叠蛋白反应（UPR）构成了一条保守且重要的细胞保护途径，旨在抵抗改变内质网蛋白质稳态的生物和非生物应激。UPR 通常被认为是细胞自主的，目前尚不清楚它是否也可以通过非细胞自主信号传导系统地发挥作用。我们在模式植物拟南芥中使用遗传方法结合微嫁接和一套分子报告基因解决了这个问题。我们证明 UPR 具有非细胞自主成分，并且我们证明这部分是由促进全身 UPR 信号转导的 UPR 转录因子 bZIP60 的细胞间运动介导的。因此，在植物等多细胞真核生物中，非细胞自主UPR信号传导至少依赖于UPR转录调节剂的系统运动。