Plastids are specialized organelles found in plants, which are endowed with their own genomes, and differ in many respects from the intracellular compartments of organisms belonging to other kingdoms of life. They differentiate into diverse, plant organ-specific variants, and are perhaps the most versatile organelles known. Chloroplasts are the green plastids in the leaves and stems of plants, whose primary function is photosynthesis. In response to environmental changes, chloroplasts use several mechanisms to coordinate their photosynthetic activities with nuclear gene expression and other metabolic pathways. Here, we focus on a redox-based regulatory network composed of thioredoxins (TRX) and TRX-like proteins. Among multiple redox-controlled metabolic activities in chloroplasts, tetrapyrrole biosynthesis is particularly rich in TRX-dependent enzymes. This review summarizes the effects of plastid-localized reductants on several enzymes of this pathway, which have been shown to undergo dithiol-disulfide transitions. We describe the impact of TRX-dependent control on the activity, stability and interactions of these enzymes, and assess its contribution to the provision of adequate supplies of metabolic intermediates in the face of diurnal and more rapid and transient changes in light levels and other environmental factors.

中文翻译：

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硫氧还蛋白依赖性控制平衡四吡咯生物合成中的代谢活动

质体是在植物中发现的特殊细胞器，它们具有自己的基因组，在许多方面与属于其他生命王国的生物的细胞内区室不同。它们分化为多种植物器官特异性变体，并且可能是已知的最通用的细胞器。叶绿体是植物叶和茎中的绿色质体，其主要功能是光合作用。为响应环境变化，叶绿体使用多种机制来协调其光合作用活动与核基因表达和其他代谢途径。在这里，我们专注于由硫氧还蛋白 (TRX) 和 TRX 样蛋白组成的基于氧化还原的调节网络。在叶绿体中多种氧化还原控制的代谢活动中，四吡咯生物合成中特别富含 TRX 依赖性酶。这篇综述总结了质体局部还原剂对该途径的几种酶的影响，这些酶已被证明会经历二硫醇-二硫化物转变。我们描述了依赖于 TRX 的控制对这些酶的活性、稳定性和相互作用的影响，并评估了它在面对昼夜和更快速和瞬态的光照水平和其他环境变化时对提供足够的代谢中间体供应的贡献。因素。