11. Unravelling the molecular basis of hydroxyapatite weathering driven by the ectomycorrhizal fungus Paxillus involutusChristina Paparokidou, 2018, doctoral dissertation Abstract: Ectomycorrhizal fungi (EMF) form symbiotic partnerships with tree roots and are able to chemically weather inorganic phosphorus (Pi)-rich minerals, supplying Pi to their host in return for photosynthates. The fungal-driven nutrient cycling from mineral weathering plays a pivotal role in ecosystems and crops productivity, as well as geochemical cycles. The aim of the study presented in this thesis is to unravel the molecular mechanisms by which the EM fungus Paxillus involutus weathers the Pi-rich mineral hydroxyapatite (HAP), either non-symbiotically or in symbiosis with its host tree Pinus sylvestris. Development of an artificial system to study P. involutus responses to varying concentration of Pi led to the identification of five high-affinity Pi transporter genes, of which the expression varies in an inversely proportional manner to Pi availability. Using the same system, whole-transcriptomic data from fungal hyphae unravelled the molecular basis of the EMF ability in Pi uptake at the global gene scale, revealing that EM symbiosis can directly affect Pi-responsive fungal genes such as the Pi transporter PiPT4. A second artificial system was used to study HAP solubilisation driven by P. involutus, which was confirmed by EDX spectroscopy data showing depletion of Pi from the HAP crystals, along with secondary minerals formation. Whole-transcriptomic analysis revealed that EM symbiosis induces a different set of HAP weathering genes in P. involutus hyphae, compared to the fungus growing non-symbiotically, including the specific expression of organic acid metabolic genes, which resulted in enhanced HAP solubilisation. Metabolomic analysis led to the identification of multiple secreted metabolites enriched in the presence of HAP in P. involutus systems grown non-symbiotically or in symbiosis with P. sylvestris seedlings. The analysis also led to the identification of putative novel fungal weathering agents. Results from transcriptomic and metabolomic analyses were ultimately combined in a model of HAP weathering by P. involutus.
Keywords: Paxillus involutus, Pinus sylvestris, ectomycorrhizal symbiosis, hydroxyapatite, SEM-EDX, fungal mineral weathering, fungal weathering metabolites, RNA-seq, UPLC-Q-TOF-MS
Published in RUNG: 03.05.2022; Views: 1475; Downloads: 0
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12. Detection of mineral dust concentration in Mediterranean and Central Europe by measuring optical absorption of dust particlesMatic Ivančič, Irena Ježek, Martin Rigler, Asta Gregorič, Balint Alfoldy, Luka Drinovec, JEAN SCIARE, Michael Pikridas, FLORIN UNGA, Andrés Alastuey, Marco Pandolfi, Jesús Yus-Díez, Griša Močnik, 2020, unpublished conference contribution Keywords: mineral dust, optical absorption, virtual impactor
Published in RUNG: 22.11.2021; Views: 1943; Downloads: 0
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14. Determination of high-time resolution mineral dust concentration in real-time by optical absorption measurementsMatic Ivančič, Irena Ježek, Martin Rigler, Asta Gregorič, Bálint Alföldy, Rok Podlipec, Luka Drinovec, Griša Močnik, 2021, published scientific conference contribution abstract Keywords: mineral dust, concentration, aerosols, air quality
Published in RUNG: 17.11.2021; Views: 1733; Downloads: 11
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15. A new optical-based technique for real-time measurements of mineral dust concentration in PM10 using a virtual impactorLuka Drinovec, Jean Sciare, IASONAS STAVROULAS, Spiros Bezantakos, Michael Pikridas, FLORIN UNGA, Chrysanthos Savvides, Bojana Višnjić, Maja Remškar, Griša Močnik, 2020, original scientific article Abstract: Atmospheric mineral dust influences Earth’s radiative
budget, cloud formation, and lifetime; has adverse
health effects; and affects air quality through the increase of
regulatory PM10 concentrations, making its real-time quantification
in the atmosphere of strategic importance. Only
few near-real-time techniques can discriminate dust aerosol
in PM10 samples and they are based on the dust chemical
composition. The online determination of mineral dust using
aerosol absorption photometers offers an interesting and
competitive alternative but remains a difficult task to achieve.
This is particularly challenging when dust is mixed with
black carbon, which features a much higher mass absorption
cross section. We build on previous work using filter photometers
and present here for the first time a highly timeresolved
online technique for quantification of mineral dust
concentration by coupling a high-flow virtual impactor (VI)
sampler that concentrates coarse particles with an aerosol absorption
photometer (Aethalometer, model AE33). The absorption
of concentrated dust particles is obtained by subtracting
the absorption of the submicron (PM1) aerosol fraction
from the absorption of the virtual impactor sample (VIPM1
method). This real-time method for detecting desert
dust was tested in the field for a period of 2 months (April and
May 2016) at a regional background site of Cyprus, in the
Eastern Mediterranean. Several intense desert mineral dust
events were observed during the field campaign with dust
concentration in PM10 up to 45 μgm
Keywords: aerosol absorption, mineral dust, on-line detection, air quality
Published in RUNG: 20.07.2020; Views: 2762; Downloads: 0
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16. A multielement analysis of Cu induced changes in the mineral profilesof Cu sensitive and tolerant populations of Silene paradoxa L.Sara Pignattelli, Ilaria Colzi, Antonella Buccianti, Ilenia Cattani, Gian Maria Beone, Henk Schat, Cristina Gonnelli, 2013, original scientific article Abstract: tThis work investigates the Cu induced changes in element profiles in contrasting ecotypes of Silene para-doxa L. A metallicolous copper tolerant population and a non-metallicolous sensitive population weregrown in hydroponics and exposed to different CuSO4treatments. Shoot and root concentrations of Ca,Cu, Fe, K, Mg, Mn, Mo, Na, P, S and Zn were evaluated through ICP-OES.Results indicated that increasing the environmental Cu concentration had a population dependenteffect on element profiles, shoot-to-root ratios and correlations among the elements. Generally, in thetolerant population Cu treatment induced a higher element accumulation in roots and had minimaleffects on the shoot element profile, thus resulting in a progressively decreasing shoot-to-root ratio foreach element. In the sensitive population element concentrations in root and shoot were much moreaffected and without a consistent trend. Copper treatment also affected the correlations between theelements, both in roots and shoots of the two populations, but more so in the sensitive population thanin the tolerant one. Thus, Cu exposure strongly disturbed element homeostasis in the sensitive population,but barely or not in the tolerant one, probably mainly due to a higher capacity to maintain proper rootfunctioning under Cu exposure in the latter. Differences in element profiles were also observed in theabsence of toxic Cu exposure. These differences may reflect divergent population-specific adaptations todifferential nutrient availability levels prevailing in the populations’ natural environments. There is noevidence of inherent side-effects of the Cu tolerance mechanism operating in the tolerant population.
Keywords: Mineral profile, Copper tolerance, Silene paradoxa, Compositional data analysis
Published in RUNG: 20.04.2020; Views: 2857; Downloads: 0
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17. Analysis of 19 Minerals and Cortisol in Red Deer Hair in Two Different Areas of the Stelvio National Park: A Preliminary StudyMarta Montillo, Tanja Peric, 2019, original scientific article Abstract: The aim of the study was to perform an investigation on the concentration of 19 minerals and
cortisol in red deer (Cervus elaphus) hair, a matrix that is easy to collect with non-invasive and painless
sampling, able to represent an integrative values of long-term substance concentrations, and able to
give useful information, also when performed on dead animals, given its extreme stability over time.
In the study thirty-five animals were included, coming from two different sides of a valley in the Stelvio
National Park, where official water analysis had pointed out elevated concentrations of As in one of the
two orographic sides. Hair cortisol concentrations were measured using a RIA(Radio Immuno Assay),
while minerals were detected using ICP-MS (Inductively Coupled Plasma- Mass Spectrometry).
Results showed a negative relationship between cortisol and some mineral concentrations (Li,
Co, As, Cd, Cr and Tl) and significant differences in some mineral concentrations between park
areas (Al, Co, Cu, Cd and Ni). As, Cr and cortisol differences approached statistical significance.
This preliminary study represents a step forward in the study of wildlife allostatic load and a valid
method for applications in wildlife management programs, in environmental studies and in public
health programs.
Keywords: hair, deer, mineral, cortisol
Published in RUNG: 27.08.2019; Views: 2970; Downloads: 97
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18. The Topic of Mining in Secondary School Literature Textbooks from 1850 to 1950Zoran Božič, 2018, original scientific article Abstract: During the first century of secondary school literature textbook publishing (from the introduction of Slovenian language as a school subject after the March Revolution in the Austrian Empire to the first Five-Year Plan after World War II) over a hundred texts featuring the topic of mining and related activities were included. The first writings have a clearly affirmative attitude towards mining, perceived and presented as a way of promoting general prosperity. The first mentions of the negative aspects of mining and the deceptive folly of coveting precious mineral resources appear towards the end of the 19th century. Only during the interwar period, however, were there various texts which presented mining as an inhumane and dangerous activity. After World War II the approach was again optimistic: in central literature textbooks mining was depicted as the glorification of socialist progress. Relevant texts were published in eight series of textbooks, the first as early as in the Bleiweis series for lower secondary schools in 1850 and the last in the ethnic Slovenian Beličič series of textbooks in 1947. The discovery of mercury in the Idrija mine was described by Valvazor, Kastelic, Hrovat and Oblak.
Keywords: natural science, didactics, mineral resources, Idrija mine, mercury
Published in RUNG: 30.08.2018; Views: 3942; Downloads: 162
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