Browsing by Author "Silva, Marta Sousa"
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- First screening of biocides, persistent organic pollutants, pharmaceutical and personal care products in Antarctic phytoplankton from Deception Island by FT-ICR-MSPublication . Duarte, Bernardo; Gameiro, Carla; Matos, Ana Rita; Figueiredo, Andreia; Silva, Marta Sousa; Cordeiro, Carlos; Caçador, Isabel; Reis-Santos, Patrick; Fonseca, Vanessa; Cabrita, Maria TeresaIn recent years, the Antarctic territory has seen a rise in the number of tourists and scientists. This has led to an increase in the anthropogenic footprint in Antarctic ecosystems, namely in terms of emerging contaminants, such as Biocides, Persistent Organic Pollutants (POPs) as well as Pharmaceutical and Personal Care Products (PPCPs). Yet scarce information on the presence of these emerging contaminants is available for trophic compartments, especially the phytoplankton community. Using high resolution Fourier-transform ion cyclotron-resonance mass spectrometry (FT-ICR-MS), an untargeted screening of the metabolome of the phytoplankton community was performed. Seventy different contaminant compounds were found to be present in phytoplankton collected at two sites in Port Foster Bay at Deception Island. These emerging contaminants included 1 polycyclic aromatic hydrocarbon (PAH), 10 biocides (acaricides, fungicides, herbicides, insecticides and nematicides), 11 POPs (flame retardants, paints and dyes, polychlorinated biphenyl (PCB), phthalates and plastic components), 5 PCPs (cosmetic, detergents and dietary compounds), 40 pharmaceutical compounds and 3 illicit drugs. Pharmaceutical compounds were, by far, the largest group of emerging contaminants found in phytoplankton cells (anticonvulsants, antihypertensives and beta-blockers, antibiotics, analgesic and anti-inflammatory drugs). The detection of several of these potentially toxic compounds at the basis of the marine food web has potentially severe impacts for the whole ecosystem trophic structure. Additionally, the present findings also point out that the guidelines proposed by the Antarctic Treaty and Protocol on Environmental Protection to the Antarctic Treaty should be revisited to avoid the proliferation of these and other PPCPs in such sensitive environments.
- Integrating metabolomics and targeted gene expression to uncover potential biomarkers of fungal/oomycetes-associated disease susceptibility in grapevinePublication . Maia, Marisa; Ferreira, António E.N.; Nascimento, Rui; Monteiro, Filipa; Traquete, Francisco; Marques, Ana P.; Cunha, Jorge; Eiras-Dias, José E.; Cordeiro, Carlos; Figueiredo, Andreia; Silva, Marta SousaVitis vinifera, one of the most cultivated fruit crops, is susceptible to several diseases particularly caused by fungus and oomycete pathogens. In contrast, other Vitis species (American, Asian) display different degrees of tolerance/resistance to these pathogens, being widely used in breeding programs to introgress resistance traits in elite V. vinifera cultivars. Secondary metabolites are important players in plant defence responses. Therefore, the characterization of the metabolic profiles associated with disease resistance and susceptibility traits in grapevine is a promising approach to identify trait-related biomarkers. In this work, the leaf metabolic composition of eleven Vitis genotypes was analysed using an untargeted metabolomics approach. A total of 190 putative metabolites were found to discriminate resistant/partial resistant from susceptible genotypes. The biological relevance of discriminative compounds was assessed by pathway analysis. Several compounds were selected as promising biomarkers and the expression of genes coding for enzymes associated with their metabolic pathways was analysed. Reference genes for these grapevine genotypes were established for normalisation of candidate gene expression. The leucoanthocyanidin reductase 2 gene (LAR2) presented a significant increase of expression in susceptible genotypes, in accordance with catechin accumulation in this analysis group. Up to our knowledge this is the first time that metabolic constitutive biomarkers are proposed, opening new insights into plant selection on breeding programs
- Untargeted metabolomics reveals antidepressant effects in a marine photosynthetic organism: the diatom Phaeodactylum tricornutum as a case studyPublication . Duarte, Bernardo; Feijão, Eduardo; Cruz de Carvalho, Ricardo; Duarte, Irina A.; Marques, Ana Patrícia; Maia, Marisa; Hertzog, Jasmine; Matos, Ana Rita; Cabrita, Maria Teresa; Caçador, Isabel; Figueiredo, Andreia; Silva, Marta Sousa; Cordeiro, Carlos; Fonseca, Vanessa F.The increased use of antidepressants, along with their increased occurrence in aquatic environments, is of concern for marine organisms. Although these pharmaceutical compounds have been shown to negatively affect marine diatoms, their mode of action in these non-target, single-cell phototrophic organisms is yet unknown. Using a Fourier-transform ion cyclotron-resonance mass spectrometer (FT-ICR-MS) we evaluated the effects of fluoxetine in the metabolomics of the model diatom Phaeodactylum tricornutum, as well as the potential use of the identified metabolites as exposure biomarkers. Diatom growth was severely impaired after fluoxetine exposure, particularly in the highest dose tested, along with a down-regulation of photosynthetic and carbohydrate metabolisms. Notably, several mechanisms that are normally down-regulated by fluoxetine in mammal organisms were also down-regulated in diatoms (e.g., glycerolipid metabolism, phosphatidylinositol signalling pathway, vitamin metabolism, terpenoid backbone biosynthesis and serotonin remobilization metabolism). Additionally, the present work also identified a set of potential biomarkers of fluoxetine exposure that were up-regulated with increasing fluoxetine exposure concentration and are of high metabolic significance following the disclosed mode of action, reinforcing the use of metabolomics approaches in ecotoxicology.