Identification of Single-Nucleotide Polymorphisms in Differentially Expressed Genes Favoring Soybean Meal Tolerance in Higher-Growth Zebrafish (Danio rerio).

Genetic variability within the same fish species could confer soybean meal (SBM) tolerance in some individuals, thus favoring growth. This study investigates the single-nucleotide polymorphisms (SNPs) in differentially expressed genes (DEGs) favoring SBM tolerance in higher-growth zebrafish (Danio rerio). In a previous work, nineteen families of zebrafish were fed a fish meal diet (100FM control diet) or SBM-based diets supplemented with saponin (50SBM + 2SPN-experimental diet), from juvenile to adult stages. Individuals were selected from families with a genotype-by-environment interaction higher (170 ± 18 mg) or lower (76 ± 10 mg) weight gain on 50SBM + 2SPN in relation to 100FM. Intestinal transcriptomic analysis using RNA-seq revealed six hundred and sixty-five differentially expressed genes in higher-growth fish fed 50SBM + 2SPN diet. In this work, using these results, 47 SNPs in DEGs were selected. These SNPs were genotyped by Sequenom in 340 zebrafish that were fed with a 50SBM + 2SPN diet or with 100FM diet. Marker-trait analysis revealed 4 SNPs associated with growth in 3 immunity-related genes (aif1l, arid3c, and cst14b.2) in response to the 50SBM + 2SPN diet (p-value < 0.05). Two SNPs belonging to aif1l y arid3c produce a positive (+19 mg) and negative (-26 mg) effect on fish growth, respectively. These SNPs can be used as markers to improve the early selection of tolerant fish to SBM diet or other plant-based diets. These genes can be used as biomarkers to identify SNPs in commercial fish, thus contributing to the aquaculture sustainability.

Pesticides in soil, groundwater and food in Latin America as part of one health.

We here report of a conference about "Pesticides in Soil, Groundwater and Food in Latin America as part of One Health" that took place at the "IV Seminario Internacional de Sanidad Agropecuaria (SISA)" in Varadero, Cuba, 8-12 May 2023. Researchers of Latin America (Argentina, Brazil, Chile, Costa Rica, Colombia, Cuba, Mexico) and Switzerland (workshop initiator) held presentations about occurrence and effects of pesticides on the environment, human health, the replacement of highly hazardous pesticides (HHP) by agroecological alternatives and the agri-food value chain. In a subsequent round table discussion, the presenters identified deficits, needs, interests and opportunities. According to them, the lack of awareness of pesticide use affects the health and safety of workers applying the chemicals. Despite Latin America representing the main agricultural area in the world with a very intense pesticide use, monitoring data of pesticides in soil, surface and groundwaters, food, as well as in humans are missing. Risks of pesticides to humans should be assessed so that authorities can withdraw or limit within "short time" the access to corresponding formulations on the market. Also, communication is not state of the art and should be improved as, e.g. the teaching of workers and farmers, how to correctly use and apply pesticides or the briefing of decision makers. Pollinators suffer from multiple stressors not the least due to pesticides, and alternatives are badly needed. On the technical side, the different analytical methods to determine residues of active ingredients and transformation products in matrices of concern should be harmonized among laboratories.Seven future actions and goals were identified to overcome the above deficits. Next steps after the publishing of this conference report are to harmonize and complete the information status of the presenters by exchanging the results/data already present. Therefore, a platform of interaction to address issues described above and to enhance collaboration shall be created. Samples of different matrices shall be exchanged to harmonize the chemical analysis and establish interlaboratory comparisons. Such activities might be facilitated by joining international associations or organizations, where researchers can offer their expertise, or by forming a new pesticide network for Central and South America that could present tailored projects to national and international organizations and funding agencies.

A multi-scenario risk assessment strategy applied to mixtures of chemicals of emerging concern in the River Aconcagua basin in Central Chile.

Environmental risk assessments strategies that account for the complexity of exposures are needed in order to evaluate the toxic pressure of emerging chemicals, which also provide suggestions for risk mitigation and management, if necessary. Currently, most studies on the co-occurrence and environmental impacts of chemicals of emerging concern (CECs) are conducted in countries of the Global North, leaving massive knowledge gaps in countries of the Global South. In this study, we implement a multi-scenario risk assessment strategy to improve the assessment of both the exposure and hazard components in the chemical risk assessment process. Our strategy incorporates a systematic consideration and weighting of CECs that were not detected, as well as an evaluation of the uncertainties associated with Quantitative Structure-Activity Relationships (QSARs) predictions for chronic ecotoxicity. Furthermore, we present a novel approach to identifying mixture risk drivers. To expand our knowledge beyond well-studied aquatic ecosystems, we applied this multi-scenario strategy to the River Aconcagua basin of Central Chile. The analysis revealed that the concentrations of CECs exceeded acceptable risk thresholds for selected organism groups and the most vulnerable taxonomic groups. Streams flowing through agricultural areas and sites near the river mouth exhibited the highest risks. Notably, the eight risk drivers among the 153 co-occurring chemicals accounted for 66-92 % of the observed risks in the river basin. Six of them are pesticides and pharmaceuticals, chemical classes known for their high biological activity in specific target organisms.

Dataset comprising pesticides, pharmaceuticals and personal care products, and industrial chemicals detected in streams and rivers of Central Chile.

Chemical pollution caused by synthetic organic chemicals at low concentrations in the environment poses a growing threat to the ecological status of aquatic ecosystems. These chemicals are regularly released into surface waters through both treated and untreated effluents from wastewater treatment plants (WWTPs), agricultural runoff, and industrial discharges. Consequently, they accumulate in surface waters, distribute amongst environmental compartments according to their physicochemical properties, and cause adverse effects on aquatic organisms. Unfortunately, there is a lack of data regarding the occurrence of synthetic organic chemicals, henceforth micropollutants, in South American freshwater ecosystems, especially in Chile. To address this research gap, we present a comprehensive dataset comprising concentrations of 153 emerging chemicals, including pesticides, pharmaceutical and personal care products (PPCPs), surfactants, and industrial chemicals. These chemicals were found to co-occur in surface waters within Central Chile, specifically in the River Aconcagua Basin. Our sampling strategy involved collecting surface water samples from streams and rivers with diverse land uses, such as agriculture, urban areas, and natural reserves. For sample extraction, we employed an on-site large-volume solid phase extraction (LVSPE) device. The resulting environmental extracts were then subjected to wide-scope chemical target screening using gas chromatography and liquid chromatography high-resolution mass spectrometry (GC- and LC-HRMS). The dataset we present holds significant value in assessing the chemical status of water bodies. It enables comparative analysis of pollution fingerprints associated with emerging chemicals across different freshwater systems. Moreover, the data can be reused for environmental risk assessment studies. Its utilisation will contribute to a better understanding of the impact and extent of chemical pollution in aquatic ecosystems, facilitating the development of effective mitigation strategies.

Analysis of Multi-Pesticide Residues and Dietary Risk Assessment in Fresh Tomatoes (Lycopersicum esculentum) from Local Supermarkets of the Metropolitan Region, Chile.

In recent years, the official authorities in Chile have reported transgressions in the maximum residue levels of pesticides in fresh vegetables. There is no official information about traceability, pesticide levels, and potential health risks. The aim of this study was to analyse pesticide residues and their corresponding dietary risk assessments in tomatoes from supermarkets in the Metropolitan Region. Pesticides were extracted using the Quick, Easy, Cheap, Effective, Rugged and Safe, QuEChERS method, and their concentrations were determined by using chromatography with HPLC-FL/UV and GC-MS/ECD/NPD, following the Analytical Quality Control and Method Validation Procedures for Pesticides Residues Analysis in Food and Feed, SANTE guide and ISO 17025:2017 standard. In addition, a dietary risk assessment was carried out by comparing Chilean data to international references. The results reported that 9% of the samples had pesticide residue levels above the maximum residue levels permitted in Chile. All the scenarios evaluated revealed the highest estimated daily intake and hazard quotients for methamidophos and chlorpyrifos. Both the active substances used were acetylcholinesterase inhibitors and were neurotoxic under chronic risk assessment. The results showed the highest chronic hazard index in the Chilean scenario for all age groups and genders. The evidence obtained revealed that methamidophos, methomyl, and chlorpyrifos should be restricted for their use in Chilean agriculture.

Postharvest Treatment of Hydrogen Sulfide Delays the Softening of Chilean Strawberry Fruit by Downregulating the Expression of Key Genes Involved in Pectin Catabolism.

Hydrogen sulfide (H2S) plays several physiological roles in plants. Despite the evidence, the role of H2S on cell wall disassembly and its implications on fleshy fruit firmness remains unknown. In this work, the effect of H2S treatment on the shelf-life, cell wall polymers and cell wall modifying-related gene expression of Chilean strawberry (Fragaria chiloensis) fruit was tested during postharvest storage. The treatment with H2S prolonged the shelf-life of fruit by an effect of optimal dose. Fruit treated with 0.2 mM H2S maintained significantly higher fruit firmness than non-treated fruit, reducing its decay and tripling its shelf-life. Additionally, H2S treatment delays pectin degradation throughout the storage period and significantly downregulated the expression of genes encoding for pectinases, such as polygalacturonase, pectate lyase, and expansin. This evidence suggests that H2S as a gasotransmitter prolongs the post-harvest shelf-life of the fruit and prevents its fast softening rate by a downregulation of the expression of key pectinase genes, which leads to a decreased pectin degradation.

Evaluation of fluopyram for management of Meloidogyne ethiopica and migratory nematodes in commercial tomato greenhouses in the Metropolitan Region of Chile.

BACKGROUND: The nematicidal effects of fluopyram were evaluated for the suppression of Meloidogyne ethiopica and migratory nematodes, Xiphinema americanum s. l., Hemicycliophora spp. and Pratylenchus spp., in two commercial tomato greenhouses in Chile. The effects of fluopyram on plant-parasitic nematodes, plant vigor and fruit yield were determined. RESULTS: Fluopyram demonstrated good potential for the management of M. ethiopica and migratory nematodes, especially during the early stages of evaluation (30-60 days after planting). There were also improvements in vigor of treated plants. A general trend in improved fruit quality was also observed, however, no significant differences in total yield were found between treatments. CONCLUSIONS: Our study is one of the first evaluations of fluopyram under field conditions against M. ethiopica. The findings suggest that this new nematicide has good potential for the management of M. ethiopica and some migratory nematodes in tomatoes cropped in greenhouses in the Metropolitan Region of Chile. © 2021 Society of Chemical Industry.

Pesticide Residues and Health Risk Assessment in Tomatoes and Lettuces from Farms of Metropolitan Region Chile.

Over the last years, the detection of pesticide residues in the official food surveillance programs of Chile has been increased, mainly in fresh vegetables such as tomatoes and lettuces. The Metropolitana Region of Chile presents the highest detections in the country. The lack of evaluations of toxicological risks in human health have increased uncertainty of the potential effects of pesticides exposures in the Chilean population. This research aims to determinate health risks assessment of pesticide residues associated to tomatoes and lettuces produced in Metropolitana Region. The findings of this study reveal that tomatoes and lettuces cultivated in the MR show more than 50% of samples with one or multiple pesticides residues. From the total samples, 16% were over the Chilean Maximum Residue Levels (MRLs). The main pesticides detected in tomatoes and lettuces were methamidophos, methomyl, difenoconazole, cyprodinil and boscalid. The results obtained using the official data of the Ministry of Health of Chile (MINSAL) compared to the World Health Organization (WHO), describe relevant risks through the Estimated Daily Intakes (EDI), Hazard Quotients (HQ) and Hazard Index (HI) for the Chilean population due to high concentrations of methamidophos, methomyl and cyprodinil. More restrictions for the use of methamidophos, methomyl, difenoconazole, cyprodinil and boscalid and effective control programs should be implemented in order to mitigate the impacts on the Chilean population.

Pesticide residues in ready-to-eat leafy vegetables from markets of Santiago, Chile, and consumer's risk.

The detection of pesticide residues in leafy vegetables has been a relevant concern in Chile over the last years. There is also a priority at the national level to propose a methodology to assess health risks. The aim of this study was to evaluate the presence of pesticide residues in ready-to-eat leafy vegetables in order to evaluate different models for health risk assessment. The models considered data of the World Health Organization (WHO) and the Ministry of Health of Chile (MINSAL). The Hazard Quotients and Hazard Indexes for the pesticides evaluated in all models decreased in the following order: methamidophos>lambda-cyhalothrin> chlorpyrifos. From a food safety perspective, the investigated samples suggest the presence of a greater health risk to consumers when compared using the official data of MINSAL, which needs appropriate attention.

Atrazine, chlorpyrifos, and iprodione effect on the biodiversity of bacteria, actinomycetes, and fungi in a pilot biopurification system with a green cover.

The use of biopurification systems can mitigate the effects of pesticide contamination on farms. The primary aim of this study was to evaluate the effect of pesticide dissipation on microbial communities in a pilot biopurification system. The pesticide dissipation of atrazine, chlorpyrifos and iprodione (35 mg kg-1 active ingredient [a.i.]) and biological activity were determined for 40 days. The microbial communities (bacteria, actinomycetes and fungi) were analyzed using denaturing gradient gel electrophoresis (DGGE). In general, pesticide dissipation was the highest by day 5 and reached 95%. The pesticides did not affect biological activity during the experiment. The structure of the actinomycete and bacterial communities in the rhizosphere was more stable during the evaluation than that in the communities in the control without pesticides. The rhizosphere fungal communities, detected using DGGE, showed small and transitory shifts with time. To conclude, rhizosphere microbial communities were not affected during pesticide dissipation in a pilot biopurification system.

Pesticide residues in leafy vegetables and human health risk assessment in North Central agricultural areas of Chile.

To investigate pesticide residue concentrations and potential human health risk, a study was conducted in 118 leafy vegetable samples collected in 2014-2015 from the North Central agricultural areas of Chile. The pesticide residues were determined using the multiresidue QuEChERS method by gas chromatography as well as high-performance liquid chromatography. The results indicated that 27% of the total samples contained pesticide residues above the maximum residue limits of each active ingredient. The maximum estimated daily intake obtained for carbon disulphide (CS2), methamidophos, azoxystrobin and cypermethrin were 0.57, 0.07, 0.06 and 0.05 mg kg-1, respectively, which was higher than their acceptable daily intake. It is concluded that inhabitants of the North Central agricultural area of Chile are not exposed to health risks through the consumption of leafy vegetables with the exception of methamidophos. Nevertheless, the high levels of methamidophos detected in leafy vegetables could be considered a potential chronic health risk.

Urea Fertilizer and pH Influence on Sorption Process of Flumetsulam and MCPA Acidic Herbicides in a Volcanic Soil.

The aim of this study was to evaluate the influence of urea fertilizer and pH on the sorption process of two acidic herbicides, flumetsulam (2',6'-difluoro-5-methyl[1,2,4]triazolo[1,5-a]pyrimidine-2-sulfonanilide) and MCPA (4-chloro--tolyloxyacetic acid), on an Andisol. Urea reduced the adsorption of MCPA but not that of flumetsulam. The Freundlich parameter of MCPA decreased from 8.5 to 5.1 mg L kg. This finding could be attributed to an increase in dissolved organic C due to an initial increase in soil pH for urea application. The higher acidic character of MCPA compared with that of flumetsulam produced a greater hydrolysis of urea, leading to a further pH increase. A marked effect of pH on the adsorption of both herbicides was observed. The organic C distribution coefficient () values for flumetsulam were in the range of 74 to 10 L kg, while those of MCPA were in the range of 208 to 45 L kg. In the kinetic studies, the pseudo-second-order model appeared to fit the data best ( > 0.994). The initial adsorption rates () ranged from 20.00 to 4.59 mg kg h for flumetsulam and from 125.00 to 25.60 mg kg hfor MCPA. Both herbicides were adsorbed rapidly during the first stage of the sorption process, and the rates of sorption were dependent on pH. The application of the Elovich and Weber-Morris models led us to conclude that mass transfer through the boundary layer and, to a lesser degree, intraparticle diffusion were influenced by the chemical character of the herbicide. These results suggest that urea application could increase leaching of acid herbicides in soils.

Selection of white-rot fungi to formulate complex and coated pellets for Reactive Orange 165 decolourization

Six strains of white-rot fungi isolated from southern Chile were evaluated for their ergosterol/biomass correlation and ligninolytic potential in solid medium to formulate pellets for Reactive Orange 165 (RO165) decolourization. The fungus Anthracophyllum discolor was selected to formulate complex pellets (fungal mycelium, sawdust, and activated carbon), coated pellets (complex pellet + alginate) and simple pellets (fungal mycelium). The activity of ligninolytic enzymes (laccase, manganese peroxidase, manganese-independent peroxidase, and lignin peroxidase) was evaluated in both the complex and coated pellets in modified Kirk medium, and the morphology of the pellets was studied using scanning electron microscopy (SEM). Complex pellets of A. discolor showed a higher enzymatic production mainly MnP (38 U L-1 at day 15) compared to coated and simple pellets. Examinations using SEM showed that both pellets produced a black core that was entrapped by a layer of fungal mycelium. Decolourization of RO165 was demonstrated with all the pellets formulated. However, the highest and fastest decolourization was obtained with complex pellets (100 percent at day 8). Therefore, complex pellets of A. discolor can be used for the biological treatment of wastewater contaminated with RO165.