TY - JOUR A1 - Gupta, Saurabh A1 - Dong, Yanni A1 - Dijkwel, Paul P. A1 - Müller-Röber, Bernd A1 - Gechev, Tsanko S. T1 - Genome-Wide Analysis of ROS Antioxidant Genes in Resurrection Species Suggest an Involvement of Distinct ROS Detoxification Systems during Desiccation JF - International Journal of Molecular Sciences N2 - Abiotic stress is one of the major threats to plant crop yield and productivity. When plants are exposed to stress, production of reactive oxygen species (ROS) increases, which could lead to extensive cellular damage and hence crop loss. During evolution, plants have acquired antioxidant defense systems which can not only detoxify ROS but also adjust ROS levels required for proper cell signaling. Ascorbate peroxidase (APX), glutathione peroxidase (GPX), catalase (CAT) and superoxide dismutase (SOD) are crucial enzymes involved in ROS detoxification. In this study, 40 putative APX, 28 GPX, 16 CAT, and 41 SOD genes were identified from genomes of the resurrection species Boea hygrometrica, Selaginella lepidophylla, Xerophyta viscosa, and Oropetium thomaeum, and the mesophile Selaginella moellendorffi. Phylogenetic analyses classified the APX, GPX, and SOD proteins into five clades each, and CAT proteins into three clades. Using co-expression network analysis, various regulatory modules were discovered, mainly involving glutathione, that likely work together to maintain ROS homeostasis upon desiccation stress in resurrection species. These regulatory modules also support the existence of species-specific ROS detoxification systems. The results suggest molecular pathways that regulate ROS in resurrection species and the role of APX, GPX, CAT and SOD genes in resurrection species during stress. KW - abiotic stress KW - desiccation KW - resurrection plants KW - ROS KW - ascorbate peroxidase KW - glutathione peroxidase KW - catalase KW - superoxide dismutase Y1 - 2019 U6 - https://doi.org/10.3390/ijms20123101 SN - 1422-0067 SN - 1661-6596 VL - 20 IS - 12 PB - Molecular Diversity Preservation International CY - Basel ER - TY - JOUR A1 - Lyall, Rafe A1 - Nikoloski, Zoran A1 - Gechev, Tsanko T1 - Comparative analysis of ROS network genes in extremophile Eukaryotes JF - International journal of molecular sciences N2 - The reactive oxygen species (ROS) gene network, consisting of both ROS-generating and detoxifying enzymes, adjusts ROS levels in response to various stimuli. We performed a cross-kingdom comparison of ROS gene networks to investigate how they have evolved across all Eukaryotes, including protists, fungi, plants and animals. We included the genomes of 16 extremotolerant Eukaryotes to gain insight into ROS gene evolution in organisms that experience extreme stress conditions. Our analysis focused on ROS genes found in all Eukaryotes (such as catalases, superoxide dismutases, glutathione reductases, peroxidases and glutathione peroxidase/peroxiredoxins) as well as those specific to certain groups, such as ascorbate peroxidases, dehydroascorbate/monodehydroascorbate reductases in plants and other photosynthetic organisms. ROS-producing NADPH oxidases (NOX) were found in most multicellular organisms, although several NOX-like genes were identified in unicellular or filamentous species. However, despite the extreme conditions experienced by extremophile species, we found no evidence for expansion of ROS-related gene families in these species compared to other Eukaryotes. Tardigrades and rotifers do show ROS gene expansions that could be related to their extreme lifestyles, although a high rate of lineage-specific horizontal gene transfer events, coupled with recent tetraploidy in rotifers, could explain this observation. This suggests that the basal Eukaryotic ROS scavenging systems are sufficient to maintain ROS homeostasis even under the most extreme conditions. KW - ROS KW - extremotolerance KW - resurrection plants Y1 - 2020 U6 - https://doi.org/10.3390/ijms21239131 SN - 1422-0067 VL - 21 IS - 23 PB - Molecular Diversity Preservation International (MDPI) CY - Basel ER - TY - JOUR A1 - Witt, Barbara A1 - Stiboller, Michael A1 - Raschke, Stefanie A1 - Friese, Sharleen A1 - Ebert, Franziska A1 - Schwerdtle, Tanja T1 - Characterizing effects of excess copper levels in a human astrocytic cell line with focus on oxidative stress markers JF - Journal of trace elements in medicine and biology : organ of the Society for Minerals and Trace Elements, GMS N2 - Background: Being an essential trace element, copper is involved in diverse physiological processes. However, excess levels might lead to adverse effects. Disrupted copper homeostasis, particularly in the brain, has been associated with human diseases including the neurodegenerative disorders Wilson and Alzheimer?s disease. In this context, astrocytes play an important role in the regulation of the copper homeostasis in the brain and likely in the prevention against neuronal toxicity, consequently pointing them out as a potential target for the neurotoxicity of copper. Major toxic mechanisms are discussed to be directed against mitochondria probably via oxidative stress. However, the toxic potential and mode of action of copper in astrocytes is poorly understood, so far. Methods: In this study, excess copper levels affecting human astrocytic cell model and their involvement in the neurotoxic mode of action of copper, as well as, effects on the homeostasis of other trace elements (Mn, Fe, Ca and Mg) were investigated. Results: Copper induced substantial cytotoxic effects in the human astrocytic cell line following 48 h incubation (EC30: 250 ?M) and affected mitochondrial function, as observed via reduction of mitochondrial membrane potential and increased ROS production, likely originating from mitochondria. Moreover, cellular GSH metabolism was altered as well. Interestingly, not only cellular copper levels were affected, but also the homeostasis of other elements (Ca, Fe and Mn) were disrupted. Conclusion: One potential toxic mode of action of copper seems to be effects on the mitochondria along with induction of oxidative stress in the human astrocytic cell model. Moreover, excess copper levels seem to interact with the homeostasis of other essential elements such as Ca, Fe and Mn. Disrupted element homeostasis might also contribute to the induction of oxidative stress, likely involved in the onset and progression of neurodegenerative disorders. These insights in the toxic mechanisms will help to develop ideas and approaches for therapeutic strategies against copper-mediated diseases. KW - Copper KW - Astrocytes KW - Toxicity KW - Mitochondria KW - ROS KW - Trace elements Y1 - 2021 U6 - https://doi.org/10.1016/j.jtemb.2021.126711 SN - 1878-3252 VL - 65 PB - Elsevier CY - München ER -