Impact of metal and metal oxide engineered nanoparticles in soil and plant systems

Nanotechnology promises huge benefits for society and capital invested in this new technology is steadily increasing, therefore there is a growing number of nanotechnology products on the market and inevitably engineered nanomaterials will be released in the atmosphere with potential risks to humans and environment. This study set out to extend the comprehension of the impact of metal (Ag, Co, Ni) and metal oxide (CeO2, Fe3O4, SnO2, TiO2) nanoparticles (NPs) on one of the most important environmental compartments potentially contaminated by NPs, the soil system, through the use of chemical and biological tools. For this purpose experiments were carried out to simulate realistic environmental conditions of wet and dry deposition of NPs, considering ecologically relevant endpoints. In detail, this thesis involved the study of three model systems and the evaluation of related issues: (i) NPs and bare soil, to assess the influence of NPs on the functions of soil microbial communities; (ii) NPs and plants, to evaluate the chronic toxicity and accumulation of NPs in edible tissues; (iii) NPs and invertebrates, to verify the effects of NPs on earthworms and the damaging of their functionality. The study highlighted that NP toxicity is generally influenced by NP core elements and the impact of NPs on organisms is specie-specific; moreover experiments conducted in media closer to real conditions showed a decrease in toxicity with respect to in vitro test or hydroponic tests. However, only a multidisciplinary approach, involving physical, chemical and biological skills, together with the use of advanced techniques, such as X-ray absorption fine structure spectroscopy, could pave the way to draw the right conclusions and accomplish a deeper comprehension of the effects of NPs on soil and soil inhabitants

Context dependency, co-introductions, novel mutualisms, and host shifts shaped the ectomycorrhizal fungal communities of the alien tree Eucalyptus globulus

The identity and relevance of the ectomycorrhizal (ECM) fungal partners of Eucalyptus globulus was investigated in NW Spain, to detect which symbionts mainly support its invasiveness. Root tips of E. globulus and of three common native plant species (Quercus robur, Pinus pinaster and Halimium lasianthum) were collected in eucalypt plantations, Q. robur forests, P. pinaster plantations and shrublands. Fungal taxonomical identity was ascertained by use of rDNA and direct sequencing. We studied diversity, composition and colonization rate of the ECM fungal communities of E. globulus to determine if fungal assemblages are host specific (i.e. similar in different habitats) or more dependent on the neighbourhood context. We also identified the type of associations formed (i.e. co-introductions, familiar or novel associations). Twenty-six ECM taxa were associated with E. globulus. Most of them engaged in novel associations with eucalypts, whereas only three fungal species were co-introduced Australian aliens. Eucalypt fungal richness, diversity and colonization rate differed between habitats, being higher in native oak forests, whereas in shrublands E. globulus showed the lowest colonization rate and diversity. The Australian fungus Descolea maculata dominated the eucalypt fungal assemblage and also spread to the native host plants, in all the habitats, posing the risk of further co-invasion.Xunta de Galicia | Ref. EM2014/03

Determinazione del valore di macchiatico per la vendita dei soprassuoli in piedi: presupposti teorici e procedimenti di calcolo

Objective of forestry firm is the sale of its standing. The forestry firm, however, before he wants to know its value. Authors take in consideration innovations registered by the forest system in the recent years, presented a detailed analysis of procedures for estimating the stumpage value, focusing mainly, on analytical process

Soil microbiota impact on Boletus edulis mycelium in chestnut orchards of different ages

Biotic factors (host plant age and soil microbiota) influencing Boletus edulis mycelium frequency and concentration have been investigated. The study was carried out in September, October and November 2018 and 2020, using six orchards of chestnut hybrid Castanea × coudercii of 40-, 10- and 3-years-old. Taxonomical identity of bacterial and fungal species was ascertained by DNA metabarcoding. Mycelium frequency and concentration of B. edulis were studied through quantitative PCR (qPCR) of soil samples. It was hypothesized that mature plants (40-years-old) have a greater soil microbiota associated at the rhizosphere, in comparison with young plants (10- and 3-years-old). This situation may reverberate on B. edulis mycelium that should be more abundant in 40-years-old orchards, also thanks to the higher number of beneficial interactions whit soil microbiota. It was found that host plant age significantly altered bacterial and fungal assemblages in both years. Bacterial fraction was dominated by the phylum Proteobacteria, Acidobacteria and Actinobacteria and showed a higher species richness and diversity in orchards of 10- and 3-years-old. Fungal phylum such as Basidiomycota was more abundant in 40- and 10-years-old orchards, whereas Ascomycota and Mortierellomycota were more abundant in the 10- and 3-years-old orchards. Mycelium frequency of B. edulis in soil samples was higher in 2020 (97 %) than in 2018 (19 %), although without differences between plant age and sampling month in each year. Boletus edulis mycelium concentration was higher in 2020 than in 2018, and in September 2020, whereas plant age did not have any effect. Of 173 bacterial taxa considered, the 12 %, 54 % and 82 % of the significant correlations with B. edulis mycelium concentration were found in 40-, 10- and 3-years-old orchards, respectively. On the other hand, of 180 fungal taxa, the 12 %, 24 % and 42 % of the significant correlations occurred in 40-, 10- and 3-years-old orchards, respectively. This investigation represents the first report about the role of soil microbiota on the ecology of B. edulis in Castanea agro-ecosystem.Ministerio de Ciencia, Innovación y Universidades | Ref. RTI2018-095568-B-I00Xunta de Galicia | Ref. ED431D 2017/18Xunta de Galicia | Ref. ED431E 2018/0

Secreted miR-210-3p as non-invasive biomarker in clear cell renal cell carcinoma

The most common subtype of renal cell carcinoma (RCC) is clear cell RCC (ccRCC). It accounts for 70-80% of all renal malignancies representing the third most common urological cancer after prostate and bladder cancer. The identification of non-invasive biomarkers for the diagnosis and responsiveness to therapy of ccRCC may represent a relevant step-forward in ccRCC management. The aim of this study is to evaluate whether specific miRNAs deregulated in ccRCC tissues present altered levels also in urine specimens. To this end we first assessed that miR-21-5p, miR-210-3p and miR-221-3p resulted upregulated in ccRCC fresh frozen tissues compared to matched normal counterparts. Next, we evidenced that miR-210-3p resulted significantly upregulated in 38 urine specimens collected from two independent cohorts of ccRCC patients at the time of surgery compared to healthy donors samples. Of note, miR- 210-3p levels resulted significantly reduced in follow-up samples. These results point to miR-210-3p as a potential non-invasive biomarker useful not only for diagnosis but also for the assessment of complete resection or response to treatment in ccRCC management

Gold nanowires-based sensor for quantification of H2O2 released by human airway epithelial cells

Hydrogen peroxide (H2O2) is a biomarker relevant for oxidative stress monitoring. Most chronic airway diseases are characterized by increased oxidative stress. To date, the main methods for the detection of this analyte are expensive and time-consuming laboratory techniques such as fluorometric and colorimetric assays. There is a growing interest in the development of electrochemical sensors for H2O2 detection due to their low cost, ease of use, sensitivity and rapid response. In this work, an electrochemical sensor based on gold nanowire arrays has been developed. Thanks to the catalytic activity of gold against hydrogen peroxide reduction and the high surface area of nanowires, this sensor allows the quantification of this analyte in a fast, efficient and selective way. The sensor was obtained by template electrodeposition and consists of gold nanowires about 5 high and with an average diameter of about 200 nm. The sensor has excellent properties in terms of reproducibility, repeatability and selectivity. The sensor was validated by quantifying the hydrogen peroxide released by human airways A549 cells exposed or not to the pro-oxidant compound rotenone. The obtained results were validated by comparing them with those obtained by flow cytometry after staining the cells with the fluorescent superoxide-sensitive Mitosox Red probe giving a very good concordance

Artificial intelligence unveils key interactions between soil properties and climate factors on Boletus edulis and B. reticulatus mycelium in chestnut orchards of different ages

The main objective of this study was to determine the possible interaction of two important abiotic factors (soil and climate) on the mycelial concentration and frequency of the ectomycorrhizal fungi Boletus edulis and B. reticulatus, using traditional statistics and artificial neural network tools. The frequency and concentration of Boletus mycelium were determined over three months (September, October, and November), and two years (2018 and 2020), in three hybrid chestnuts (Castanea × coudercii) orchards of 40-, 10-, and 3- years-old, using real-time qPCR. Statistical analysis revealed a significant effect of the year on B. edulis mycelium concentration and of the sampling plot (different tree ages) on B. reticulatus frequency. The combination of artificial intelligence networks (ANN) with fuzzy logic, named neurofuzzy logic (NF), allowed the construction of two robust models. In the first, using year, month, and sampling plot as inputs, NF identified hidden interactions between year and month on B. edulis mycelium concentration and between sampling plot and sampling month on B. reticulatus mycelium frequency, thus improving the information obtained from the statistical analysis. In the second model, those three factors were disaggregated into 44 inputs, including 20 soil properties and 24 climatic factors, being NF able to select only 8 as critical factors to explain the variability found in both ectomycorrhizal Boletus species regarding mycelial frequency and concentration. Specifically, NF selected two chemical soil properties (cation exchange capacity and total carbon) and three physical properties (macroaggregates, total porosity, and soil moisture at field capacity), as well as their interactions with three climatic elements (cumulative difference between precipitation and potential evapotranspiration (P-PET-1-2) and water deficit (WD-1-2) in the previous two months and excess water (WE-1) in the month prior to sampling. These results provide a much deeper understanding and new insights into the ecology and the role of abiotic factors which explain the different mycelial development patterns of ectomycorrhizal fungi such as B. edulis and B. reticulatus in chestnut agroecosystems

An Alkaloid from a Highly Invasive Seaweed Increases the Voracity and Reproductive Output of a Model Fish Species

The invasive macroalga Caulerpa cylindracea has spread widely in the Mediterranean Sea, becoming a favorite food item for native fish for reasons yet unknown. By using a combination of behavioral, morphological, and molecular approaches, herein we provide evidence that the bisindole alkaloid caulerpin, a major secondary metabolite of C. cylindracea, significantly increases food intake in the model fish Danio rerio, influencing the regulation of genes involved in the orexigenic pathway. In addition, we found that the compound improves fish reproductive performance by affecting the hypothalamus-pituitary-gonadal axis. The obtained results pave the way for the possible valorization of C. cylindracea as a sustainable source of a functional feed additive of interest to face critical challenges both in aquaculture and in human nutrition