| 1. |
- Bonnefille, Bénilde, et al.
(författare)
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Nontarget Analysis of Polluted Surface Waters in Bangladesh Using Open Science Workflows
- 2023
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Ingår i: Environmental Science and Technology. - 0013-936X .- 1520-5851. ; 57:17, s. 6808-6824
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Tidskriftsartikel (refereegranskat)abstract
- Nontarget mass spectrometry has great potential to reveal patterns of water contamination globally through community science, but few studies are conducted in low-income countries, nor with open-source workflows, and few datasets are FAIR (Findable, Accessible, Interoperable, Reusable). Water was collected from urban and rural rivers around Dhaka, Bangladesh, and analyzed by liquid chromatography high-resolution mass spectrometry in four ionization modes (electrospray ionization +/-, atmospheric pressure chemical ionization +/-) with data -independent MS2 acquisition. The acquisition strategy was complementary: 19,427 and 7365 features were unique to ESI and APCI, respectively. The complexity of water pollution was revealed by >26,000 unique molecular features resolved by MS-DIAL, among which >20,000 correlated with urban sources in Dhaka. A major wastewater treatment plant was not a dominant pollution source, consistent with major contributions from uncontrolled urban drainage, a result that encourages development of further wastewater infrastructures. Matching of deconvoluted MS2 spectra to public libraries resulted in 62 confident annotations (i.e., Level 1-2a) and allowed semiquantification of 42 analytes including pharmaceuticals, pesticides, and personal care products. In silico structure prediction for the top 100 unknown molecular features associated with an urban source allowed 15 additional chemicals of anthropogenic origin to be annotated (i.e., Level 3). The authentic MS2 spectra were uploaded to MassBank Europe, mass spectral data were openly shared on the MassIVE repository, a tool (i.e., MASST) that could be used for community science environmental surveillance was demonstrated, and current limitations were discussed.
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| 2. |
- Papazian, Stefano, 1986-
(författare)
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Black mustard and the butterfly effect : metabolomics of plant-insect interactions under multiple stress conditions
- 2017
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- One main goal of ecological research is to understand nature´s complexity, in order to predict the potential impact of environmental perturbations. In this thesis, I investigate the ecological interactions between some of the most ancient organisms living on our planet: plants and insects.Focus of my research is the interaction between the wild brassicaceous plant black mustard (Brassica nigra L.) and its specialist insect herbivore, the large white cabbage butterfly (Pieris brassicae L). Both organisms are well characterized model species used in chemical ecology research.Using different analytical techniques, such as liquid and gas chromatography coupled to mass-spectrometry (LC- and GC-MS) and headspace collection of volatile organic compounds (VOCs), I apply the approach of metabolomics and systems biology to the field of ecology to explore the metabolic changes occurring inside the plants exposed to biotic and abiotic stresses.Particularly, I study the plant metabolic responses against P. brassicae chewing caterpillars during sequential treatment exposure to: abiotic stress by the oxidative air pollutant ozone (O3); dual herbivory with specialist Brevicoryne brassicae piercing-sucking aphids; and chemical induction of plant defences with the oxylipin phytohormone methyl-jasmonate (MeJA).Results show how during herbivore-induced responses, changes in defence- and growth-metabolic processes are tightly connected to stress protection mechanisms, indicating that plants actively reprogram their inner metabolic networks in order to adapt to consecutive changes in the environment.This thesis illustrates how evaluating the plant metabolome in its entirety rather than single metabolites, can help us understanding plant responses towards abiotic and biotic stresses, and improve our ability to predict how constant shifts in the environment affect plant physiology and ecology.
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| 3. |
- Papazian, Stefano, 1986-, et al.
(författare)
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Dynamics of plant responses to combinations of air pollutants
- 2020
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Ingår i: Plant Biology. - : Wiley-Blackwell Publishing Inc.. - 1435-8603 .- 1438-8677. ; 22, s. 68-83
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Forskningsöversikt (refereegranskat)abstract
- The focus of this review is on how plants respond to combinations of multiple air pollutants. Global pollution trends, plant physiological responses and ecological perspectives in natural and agricultural systems are all discussed. In particular, we highlight the importance of studying sequential or simultaneous exposure of plants to pollutants, rather than exposure to individual pollutants in isolation, and explore how these responses may interfere with the way plants interact with their biotic community. Air pollutants can alter the normal physiology and metabolic functioning of plants. Here we describe how the phenotypic and molecular changes in response to multiple pollutants can differ compared to those elicited by single pollutants, and how different responses have been observed between plants in the field and in controlled laboratory conditions and between trees and crop plants. From an ecological perspective, we discuss how air pollution can result in greater susceptibility to biotic stressors and in direct or indirect effects on interactions with organisms that occupy higher trophic levels. Finally, we provide an overview of the potential uses of plants to mitigate air pollution, exploring the feasibility for pollution removalviathe processes of bio-accumulation and phytoremediation. We conclude by proposing some new directions for future research in the field.
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| 4. |
- Papazian, Stefano, 1986-, et al.
(författare)
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Herbivore-Induced Metabolic Responses in Brassica nigra are Shaped by Leaf Ontogeny
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- In order to defend, plants rely on quick metabolic reconfigurations. Here weinvestigated plant herbivore-induced responses asking: 1) how exposure to methyljasmonate(MeJA) and herbivory alter plant defence and growth metabolism, and 2)are herbivore-induced responses concentrated in tissues with higher fitness value, aspredicted by the optimal defence (OD) theory? We analysed the leaf metabolome of black mustard (B. nigra) in response to MeJAand/or feeding by specialist caterpillars of the large white cabbage butterfly (Pierisbrassicae). Shifts in defence-related (secondary) and growth-related (primary)metabolites were initially evaluated on fully expanded mature leaves and thenfollowed across leaf ontogeny. MeJA enhanced herbivore induced-responses and increased the plant resistanceagainst sequential herbivory. Responses were focused in young leaves andcharacterized by changes in defence- (glucosinolates, phenolics) and growth- (aminoacids, sugars, organic acids) metabolism, including asymmetric accumulation ofcentral tricarboxylic acid cycle (TCA) intermediates. MeJA application enhanced the plant resistance towards herbivory and, consistentlywith the OD theory, herbivore-induced responses were prioritized in young leaves.However, shifts in the plant were not limited to higher defences but affected growthmetabolism including regulation of energy pathways and increased leaf senescence.These effects deserve attention by future ecological and applied research on plantinsectinteractions.
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| 5. |
- Papazian, Stefano, 1986-, et al.
(författare)
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Leaf metabolic signatures induced by real and simulated herbivory in black mustard (Brassica nigra)
- 2019
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Ingår i: Metabolomics. - : Springer. - 1573-3882 .- 1573-3890. ; 15:10
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Tidskriftsartikel (refereegranskat)abstract
- Introduction The oxylipin methyl jasmonate (MeJA) is a plant hormone active in response signalling and defence against herbivores. Although MeJA is applied experimentally to mimic herbivory and induce plant defences, its downstream effects on the plant metabolome are largely uncharacterized, especially in the context of primary growth and tissue-specificity of the response. Objectives We investigated the effects of MeJA-simulated and real caterpillar herbivory on the foliar metabolome of the wild plant Brassica nigra and monitored the herbivore-induced responses in relation to leaf ontogeny. Methods As single or multiple herbivory treatments, MeJA- and mock-sprayed plants were consecutively exposed to caterpillars or left untreated. Gas chromatography (GC) and liquid chromatography (LC) time-of-flight mass-spectrometry (TOF-MS) were combined to analyse foliar compounds, including central primary and specialized defensive plant metabolites. Results Plant responses were stronger in young leaves, which simultaneously induced higher chlorophyll levels. Both MeJA and caterpillar herbivory induced similar, but not identical, accumulation of tricarboxylic acids (TCAs), glucosinolates (GSLs) and phenylpropanoids (PPs), but only caterpillar feeding led to depletion of amino acids. MeJA followed by caterpillars caused higher induction of defence compounds, including a three-fold increase in the major defence compound allyl-GSL (sinigrin). When feeding on MeJA-treated plants, caterpillars gained less weight indicative of the reduced host-plant quality and enhanced resistance. Conclusions The metabolomics approach showed that plant responses induced by herbivory extend beyond the regulation of defence metabolism and are tightly modulated throughout leaf development. This leads to a new understanding of the plant metabolic potential that can be exploited for future plant protection strategies.
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| 6. |
- Papazian, Stefano, 1986-, et al.
(författare)
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Nontarget mass spectrometry and in silico molecular characterization of air pollution from the Indian subcontinent
- 2022
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Ingår i: Communications Earth & Environment. - : Springer Science and Business Media LLC. - 2662-4435. ; 3:1
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Tidskriftsartikel (refereegranskat)abstract
- A combination of high-resolution mass spectrometry and computational molecular characterization techniques can structurally annotate up to 17% of organic compounds in fine particulate matter in highly polluted air sampled in the Maldives. Fine particulate-matter is an important component of air pollution that impacts health and climate, and which delivers anthropogenic contaminants to remote global regions. The complex composition of organic molecules in atmospheric particulates is poorly constrained, but has important implications for understanding pollutant sources, climate-aerosol interactions, and health risks of air pollution exposure. Here, comprehensive nontarget high-resolution mass spectrometry was combined with in silico structural prediction to achieve greater molecular-level insight for fine particulate samples (n = 40) collected at a remote receptor site in the Maldives during January to April 2018. Spectral database matching identified 0.5% of 60,030 molecular features observed, while a conservative computational workflow enabled structural annotation of 17% of organic structures among the remaining molecular dark matter. Compared to clean air from the southern Indian Ocean, molecular structures from highly-polluted regions were dominated by organic nitrogen compounds, many with computed physicochemical properties of high toxicological and climate relevance. We conclude that combining nontarget analysis with computational mass spectrometry can advance molecular-level understanding of the sources and impacts of polluted air.
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| 7. |
- Papazian, Stefano, 1986-, et al.
(författare)
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Silicone Foam for Passive Sampling and Nontarget Analysis of Air
- 2023
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Ingår i: Environmental Science and Technology Letters. - : American Chemical Society (ACS). - 2328-8930. ; 10:11, s. 989-997
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Tidskriftsartikel (refereegranskat)abstract
- The airborne chemical exposome is a dynamic complex mixture of gases and particles, and despite clear links to chronic disease and premature death, its molecular composition and variability remains largely uncharacterized. To overcome this, we aimed to pair nontarget analysis by high-resolution mass spectrometry (HRMS) with an inexpensive and stable passive sampling media for airborne gases and particles. To this end, we synthesized silicone (polydimethylsiloxane; PDMS) foam disks resulting in a low cost (0.02$/disk) and ultraclean material suitable for analysis by gas or liquid chromatography (GC/LC)HRMS. When tested for indoor passive sampling over 1-3 months, alongside a PDMS sheet, PDMS foam accumulated many nonpolar gas phase environmental contaminants (e.g., polychlorinated biphenyls), and a surprisingly complex mixture of larger polar substances (e.g., oxygen, nitrogen and sulfur-containing) that were absent from the PDMS sheet, suggesting sampling of the particulate phase. The airborne molecular discovery potential was further demonstrated using an open-science LC-HRMS workflow integrating molecular networks and in silico structural predictions tailored on PubChemLite for Exposomics, which revealed series of known and unknown substances, including aromatic nitrophenols and sulfonyls. Future studies may benefit from implementing PDMS foam as wearable or stationary passive samplers to support advances in understanding exposure and contaminant sources in the indoor, outdoor, and personal airborne exposomes.
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| 8. |
- Ponzio, Camille, et al.
(författare)
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Dual herbivore attack and herbivore density affect metabolic profiles of Brassica nigra leaves
- 2017
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Ingår i: Plant, Cell and Environment. - : Wiley. - 0140-7791 .- 1365-3040. ; 40:8, s. 1356-1367
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Tidskriftsartikel (refereegranskat)abstract
- Plant responses to dual herbivore attack are increasingly studied, but effects on the metabolome have largely been restricted to volatile metabolites and defence-related non-volatile metabolites. However, plants subjected to stress, such as herbivory, undergo major changes in both primary and secondary metabolism. Using a naturally occurring system, we investigated metabolome-wide effects of single or dual herbivory on Brassica nigra plants by Brevicoryne brassicae aphids and Pieris brassicae caterpillars, while also considering the effect of aphid density. Metabolomic analysis of leaf material showed that single and dual herbivory had strong effects on the plant metabolome, with caterpillar feeding having the strongest influence. Additionally, aphid-density-dependent effects were found in both the single and dual infestation scenarios. Multivariate analysis revealed treatment-specific metabolomic profiles, and effects were largely driven by alterations in the glucosinolate and sugar pools. Our work shows that analysing the plant metabolome as a single entity rather than as individual metabolites provides new insights into the subcellular processes underlying plant defence against multiple herbivore attackers. These processes appear to be importantly influenced by insect density.
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| 9. |
- Sdougkou, Kalliroi, et al.
(författare)
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Phospholipid Removal for Enhanced Chemical Exposomics in Human Plasma
- 2023
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Ingår i: Environmental Science and Technology. - : American Chemical Society (ACS). - 0013-936X .- 1520-5851. ; 57, s. 10173-10184
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Tidskriftsartikel (refereegranskat)abstract
- Chemical exposomics in human plasma wasenhanced by an optimizedphospholipid removal step that increased targeted method sensitivitywhile also revealing >13,000 new molecular features by LC-HRMSnon-targetedacquisition. The challenge of chemical exposomics in human plasmais the 1000-foldconcentration gap between endogenous substances and environmentalpollutants. Phospholipids are the major endogenous small moleculesin plasma, thus we validated a chemical exposomics protocol with anoptimized phospholipid-removal step prior to targeted and non-targetedliquid chromatography high-resolution mass spectrometry. Increasedinjection volume with negligible matrix effect permitted sensitivemulticlass targeted analysis of 77 priority analytes; median MLOQ= 0.05 ng/mL for 200 & mu;L plasma.In non-targeted acquisition, mean total signal intensities of non-phospholipidswere enhanced 6-fold in positive (max 28-fold) and 4-fold in negativemode (max 58-fold) compared to a control method without phospholipidremoval. Moreover, 109 and 28% more non-phospholipid molecular featureswere detected by exposomics in positive and negative mode, respectively,allowing new substances to be annotated that were non-detectable withoutphospholipid removal. In individual adult plasma (100 & mu;L, n = 34), 28 analytes were detected and quantified among10 chemical classes, and quantitation of per- and polyfluoroalkylsubstances (PFAS) was externally validated by independent targetedanalysis. Retrospective discovery and semi-quantification of PFAS-precursorswas demonstrated, and widespread fenuron exposure is reported in plasmafor the first time. The new exposomics method is complementary tometabolomics protocols, relies on open science resources, and canbe scaled to support large studies of the exposome.
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