Chodasiewicz Monika, Sokolowska Ewelina Maria, Nelson-Dittrich Anna C, Masiuk Aleksandra, Beltran Juan Camilo Moreno, Nelson Andrew D L, Skirycz Aleksandra
Max Planck Institute of Molecular Plant Physiology, Golm, Germany.
Center for Desert Agriculture, Biological and Environmental Science and Engineering Division (BESE), King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia.
Front Plant Sci. 2020 Oct 30;11:595792. doi: 10.3389/fpls.2020.595792. eCollection 2020.
Plants exhibit different physiological and molecular responses to adverse changes in their environment. One such molecular response is the sequestration of proteins, RNAs, and metabolites into cytoplasmic bodies called stress granules (cSGs). Here we report that, in addition to cSGs, heat stress also induces the formation of SG-like foci (cGs) in the chloroplasts of the model plant . Similarly to the cSGs, (i) cpSG assemble rapidly in response to stress and disappear when the stress ceases, (ii) cpSG formation is inhibited by treatment with a translation inhibitor (lincomycin), and (iii) cpSG are composed of a stable core and a fluid outer shell. A previously published protocol for cSG extraction was successfully adapted to isolate cpSG, followed by protein, metabolite, and RNA analysis. Analogously to the cSGs, cpSG sequester proteins essential for SG formation, dynamics, and function, also including RNA-binding proteins with prion-like domain, ATPases and chaperones, and the amino acids proline and glutamic acid. However, the most intriguing observation relates to the cpSG localization of proteins, such as a complete magnesium chelatase complex, which is involved in photosynthetic acclimation to stress. These data suggest that cpSG have a role in plant stress tolerance.
植物对其环境中的不利变化表现出不同的生理和分子反应。一种这样的分子反应是将蛋白质、RNA和代谢物隔离到称为应激颗粒（cSGs）的细胞质体中。在这里，我们报告说，除了cSGs之外，热应激还会在模式植物的叶绿体中诱导形成类似SG的病灶（cGs）。与cSGs类似，（i）cpSGs在应激反应中迅速组装，并在应激停止时消失，（ii）cpSGs的形成受到翻译抑制剂（林可霉素）处理的抑制，（iii）cpSGs由一个稳定的核心和一个流体外壳组成。先前发表的cSGs提取方案成功地适用于分离cpSGs，随后进行蛋白质、代谢物和RNA分析。与cSGs类似，cpSGs隔离了SGs形成、动态和功能所必需的蛋白质，还包括具有朊病毒样结构域的RNA结合蛋白、ATP酶和伴侣蛋白，以及氨基酸脯氨酸和谷氨酸。然而，最引人注目的观察结果与蛋白质的cpSG定位有关，例如参与光合适应胁迫的完整镁螯合酶复合物。这些数据表明cpSGs在植物胁迫耐受性中发挥作用。
