About this Research Topic
Actual changes in environmental conditions, mainly by anthropogenic causes, can lead to toxic events. The growing human population associated with nutrient pollution promotes variations in coastal nutrient loads from land runoff. Environmental modifications are due to altered abiotic parameters or physical dynamics, such as warmer ocean water sand stratification, that are caused by climatic changes. Instant responses of marine plants to adverse environmental conditions involve excess production of reactive oxygen species (ROS) and reactive nitrogen species (RNS). The physiological and ecological roles for these alterations are yet to be fully elucidated.
Phytoplankton is the most significant primary producer in the ocean (50% of global primary production), sustaining the pelagic food chains in the aquatic ecosystems. Phytoplankton is a substantial sink for CO2 in marine ecosystems. If these organisms are adversely affected, then the surrounding ecosystem may also feel the effects, either directly or indirectly, from the lack of a food source. Thus, physiological pathways, including cell functionality, membrane stability, antioxidant enzyme activities, gene expression, and cell signaling, would be put at risk in many organisms. A deeper biochemical analysis of the transcriptional levels and enzymatic activity of identified proteins may help the understanding of the mechanisms of the metabolism of photosynthetic systems. Moreover, this knowledge would allow the finding of strategies that could avoid, or at least limit, the drastic effects of global climate changes in this complex scenario. Even though, oxidative/nitrosative actions are not the only factors that lead to deleterious alterations on the organisms, to clarify these effects could be a key factor for future advances in this field. In this regard, the microalgae community exhibits change when exposed in situ to higher temperatures. Since temperature, oxygen (O2) consumption, availability of food, endogenous rhythms, ozone concentration and UV irradiation, and harmful marine blooms (HMBs), fluctuate accordingly to cycles, these factors might be potential stressors for aquatic and terrestrial photosynthetic organisms.
In this Research Topic, we focus on the following aspects:
-Oxygen and nitrogen radical generation by exposure of aquatic and terrestrial organisms to environmental alterations due to global changes.
-Modifications in the antioxidant capacity in the organisms exposed to changes in salinity, temperature, metal and nutrients, ozone depletion and contamination due to anthropogenic factors.
-Adaptation mechanisms triggered in the organisms to survive the changing environment.
-Signaling pathways involved in the adaptive processes.
-Possible strategies to minimize the dangerous effects of oxidative and nitrosative stress dependent on global changes.
Special focus will be made on oxidative and/or nitrosative cellular balance on cells and tissues. Even though in situ field research is less controlled than laboratory studies in which the organisms are directly exposed to the stressors, both types of approaches are encouraged. Experimental evidence of the interaction between the external factors, both biotic and abiotic, and the biological changes are of interest.
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