Sandalio L M, Romero-Puertas M C
Department of Biochemistry and Molecular and Cellular Biology of Plants, Estación Experimental del Zaidín, CSIC, Profesor Albareda 1, 18008, Granada, Spain
Department of Biochemistry and Molecular and Cellular Biology of Plants, Estación Experimental del Zaidín, CSIC, Profesor Albareda 1, 18008, Granada, Spain.
Ann Bot. 2015 Sep;116(4):475-85. doi: 10.1093/aob/mcv074. Epub 2015 Jun 12.
Peroxisomes are highly dynamic, metabolically active organelles that used to be regarded as a sink for H2O2 generated in different organelles. However, peroxisomes are now considered to have a more complex function, containing different metabolic pathways, and they are an important source of reactive oxygen species (ROS), nitric oxide (NO) and reactive nitrogen species (RNS). Over-accumulation of ROS and RNS can give rise oxidative and nitrosative stress, but when produced at low concentrations they can act as signalling molecules.
This review focuses on the production of ROS and RNS in peroxisomes and their regulation by antioxidants. ROS production is associated with metabolic pathways such as photorespiration and fatty acid β-oxidation, and disturbances in any of these processes can be perceived by the cell as an alarm that triggers defence responses. Genetic and pharmacological studies have shown that photorespiratory H2O2 can affect nuclear gene expression, regulating the response to pathogen infection and light intensity. Proteomic studies have shown that peroxisomal proteins are targets for oxidative modification, S-nitrosylation and nitration and have highlighted the importance of these modifications in regulating peroxisomal metabolism and signalling networks. The morphology, size, number and speed of movement of peroxisomes can also change in response to oxidative stress, meaning that an ROS/redox receptor is required. Information available on the production and detection of NO/RNS in peroxisomes is more limited. Peroxisomal homeostasis is critical for maintaining the cellular redox balance and is regulated by ROS, peroxisomal proteases and autophagic processes.
Peroxisomes play a key role in many aspects of plant development and acclimation to stress conditions. These organelles can sense ROS/redox changes in the cell and thus trigger rapid and specific responses to environmental cues involving changes in peroxisomal dynamics as well as ROS- and NO-dependent signalling networks, although the mechanisms involved have not yet been established. Peroxisomes can therefore be regarded as a highly important decision-making platform in the cell, where ROS and RNS play a determining role.
过氧化物酶体是高度动态、代谢活跃的细胞器，过去曾被视为不同细胞器中产生的过氧化氢的汇聚场所。然而，现在过氧化物酶体被认为具有更复杂的功能，包含不同的代谢途径，并且它们是活性氧（ROS）、一氧化氮（NO）和活性氮（RNS）的重要来源。ROS和RNS的过度积累会导致氧化应激和亚硝化应激，但当它们以低浓度产生时，可作为信号分子发挥作用。
本综述聚焦于过氧化物酶体中ROS和RNS的产生及其受抗氧化剂的调控。ROS的产生与光呼吸和脂肪酸β-氧化等代谢途径相关，这些过程中任何一个的紊乱都可被细胞视为触发防御反应的警报。遗传和药理学研究表明，光呼吸产生的过氧化氢可影响核基因表达，调节对病原体感染和光照强度的反应。蛋白质组学研究表明，过氧化物酶体蛋白是氧化修饰、S-亚硝基化和硝化的靶点，并突出了这些修饰在调节过氧化物酶体代谢和信号网络中的重要性。过氧化物酶体的形态、大小、数量和移动速度也可因氧化应激而改变，这意味着需要一个ROS/氧化还原受体。关于过氧化物酶体中NO/RNS的产生和检测的可用信息更为有限。过氧化物酶体的稳态对于维持细胞氧化还原平衡至关重要，并受ROS、过氧化物酶体蛋白酶和自噬过程的调控。
过氧化物酶体在植物发育和适应胁迫条件的许多方面发挥关键作用。这些细胞器能够感知细胞内的ROS/氧化还原变化，从而触发对环境信号的快速而特异性反应，包括过氧化物酶体动态变化以及ROS和NO依赖的信号网络的变化，尽管其中涉及的机制尚未明确。因此，过氧化物酶体可被视为细胞中一个极其重要的决策平台，其中ROS和RNS起着决定性作用。
