Peroxiredoxin (Prx) is a relatively recently discovered antioxidant enzyme family that scavenges peroxides and is known to be present in organisms from biological taxa ranging from bacteria to multicellular eukaryotes, including photosynthetic organisms. Although there have been many studies of the Prx family in higher plants, green algae, and cyanobacteria, few studies have concerned raphidophytes and dinoflagellates, which are among the eukaryotic algae that cause harmful algal blooms (HABs). In our proteomic study using 2-D electrophoresis, we found a highly expressed 2-Cys peroxiredoxin (2-CysPrx) in the raphidophyte Chattonella marina var. antiqua, a species that induces mass mortality of aquacultured fish. The abundance of the C. marina 2-CysPrx enzyme was highest in the exponential growth phase, during which photosynthetic activity was high, and it then decreased by about a factor of two during the late stationary growth phase. This pattern suggested that 2-CysPrx is a key enzyme involved in the maintenance of high photosynthesis activity. In addition, the fact that the depression of photosynthesis by excessively high irradiance was more severe in the 2-CysPrx low-expression strain (wild type) than in the normal-expression strain (wild type) of C. marina suggested that 2-CysPrx played a critical role in protecting the cell from oxidative stress caused by exposure to excessively high irradiance. In the field of HAB research, estimates of growth potential have been desired to predict the population dynamics of HABs for mitigating damage to fisheries. Therefore, omics approaches have recently begun to be applied to elucidate the physiology of the growth of HAB species. In this review, we describe the progress we have made using a molecular physiological approach to identify the roles of 2-CysPrx and other antioxidant enzymes in mitigating environmental stress associated with strong light and high temperatures and resultant oxidative stress. We also describe results of a survey of expressed Prx genes and their growth-phase-dependent behavior in C. marina using RNA-seq analysis. Finally, we speculate about the function of these genes and the ecological significance of 2-CysPrx, such as its involvement in circadian rhythms and the toxicity of C. marina to fish.

中文翻译：

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有害藻华种沙门氏菌过氧化物酶的研究进展

Peroxiredoxin（Prx）是一个相对较新发现的抗氧化剂酶家族，可清除过氧化物，并且已知存在于从细菌到多细胞真核生物（包括光合生物）的生物分类单元中。尽管已经对高等植物，绿藻和蓝细菌中的Prx家族进行了许多研究，但很少有研究涉及引起有害藻华（HABs）的真核藻中的斜纹藻和鞭毛藻。在我们使用2-D电泳的蛋白质组学研究中，我们在斜纹藻Chattonella marina var中发现了高表达的2-Cys过氧化物酶（2-CysPrx）。antiqua，一种引起水产养殖鱼类大量死亡的物种。C.码头的丰富2-CysPrx酶在指数生长期最高，在此期间光合活性很高，然后在静止的生长期后期降低了约两倍。这种模式表明2-CysPrx是参与维持高光合作用活性的关键酶。另外，2-CysPrx低表达菌株（野生型）的光合作用过强导致光合作用的抑制比滨海梭菌的正常表达菌株（野生型）更严重。提示2-CysPrx在保护细胞免受因暴露于过高辐照度引起的氧化应激中起关键作用。在HAB研究领域，人们需要对生长潜力进行估算，以预测HAB的种群动态，以减轻对渔业的破坏。因此，最近已经开始使用组学方法来阐明HAB物种生长的生理机制。在这篇综述中，我们描述了使用分子生理学方法鉴定2-CysPrx和其他抗氧化酶在减轻与强光和高温有关的环境压力以及由此产生的氧化应激中的作用所取得的进展。我们还描述了表达的Prx基因及其在C.滨海中的生长阶段依赖性行为的调查结果。使用RNA序列分析。最后，我们推测了这些基因的功能以及2-CysPrx的生态学意义，例如其参与昼夜节律和C. marina对鱼类的毒性。