质体通过逆行信号传递它们的发育和生理状态到细胞核,允许适当调整核基因表达。质体生物发生过程中的信号和成熟叶绿体对环境变化的反应被称为“生物成因”和“操作控制”,分别。研究生物信号的一个突出例子是筛选枪(基因组未偶联)突变体。尽管前五个枪支突变体是30年前发现的,GUN蛋白在逆行信号中的功能仍然存在争议,GUN1的争议很大。这里,我们提供了背景信息,并批判性地讨论了最近提出的解决GUN相关信号传导的概念和一些新颖的枪支突变体。此外,考虑血红素作为逆行信号的候选者,我们重新审视血红素生物合成和质体出口的空间组织。虽然这篇综述侧重于GUN途径,我们还重点介绍了在鉴定和阐明调节绿藻和植物适应反应的叶绿体衍生信号方面的最新进展。这里,应激诱导的未折叠/组装叶绿体蛋白的积累引起叶绿体特异性未折叠蛋白反应,这导致核编码的伴侣和蛋白酶的表达水平发生变化,以恢复质体蛋白的稳态。我们还解决了叶绿体衍生的信号对于激活类黄酮生物合成的重要性,从而导致通过蔗糖非发酵1相关蛋白激酶1在胁迫适应过程中产生花青素。最后,提供了在蛋白质组和代谢组水平上鉴定和定量室间信号级联的框架,我们讨论了细胞器-细胞核交流解剖的未来方向。
Plastids communicate their developmental and physiological status to the nucleus via retrograde signaling, allowing nuclear gene expression to be adjusted appropriately. Signaling during plastid biogenesis and responses of mature chloroplasts to environmental changes are designated \"biogenic\" and \"operational\" controls, respectively. A prominent example of the investigation of biogenic signaling is the screen for gun (genomes uncoupled) mutants. Although the first five gun mutants were identified 30 years ago, the functions of GUN proteins in retrograde signaling remain controversial, and that of GUN1 is hotly disputed. Here, we provide background information and critically discuss recently proposed concepts that address GUN-related signaling and some novel gun mutants. Moreover, considering heme as a candidate in retrograde signaling, we revisit the spatial organization of heme biosynthesis and export from plastids. Although this
review focuses on GUN pathways, we also highlight recent progress in the identification and elucidation of chloroplast-derived signals that regulate the acclimation response in green algae and plants. Here, stress-induced accumulation of unfolded/misassembled chloroplast proteins evokes a chloroplast-specific unfolded protein response, which leads to changes in the expression levels of nucleus-encoded chaperones and proteases to restore plastid protein homeostasis. We also address the importance of chloroplast-derived signals for activation of flavonoid biosynthesis leading to production of anthocyanins during stress acclimation through sucrose non-fermenting 1-related protein kinase 1. Finally, a framework for identification and quantification of intercompartmental signaling cascades at the proteomic and metabolomic levels is provided, and we discuss future directions of dissection of organelle-nucleus communication.