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Nature Chemical Biology Jan 2024Plants sense abscisic acid (ABA) using chemical-induced dimerization (CID) modules, including the receptor PYR1 and HAB1, a phosphatase inhibited by ligand-activated...
Plants sense abscisic acid (ABA) using chemical-induced dimerization (CID) modules, including the receptor PYR1 and HAB1, a phosphatase inhibited by ligand-activated PYR1. This system is unique because of the relative ease with which ligand recognition can be reprogrammed. To expand the PYR1 system, we designed an orthogonal '*' module, which harbors a dimer interface salt bridge; X-ray crystallographic, biochemical and in vivo analyses confirm its orthogonality. We used this module to create PYR1*/HAB1* and PYR1*/HAB1*, which possess nanomolar sensitivities to their activating ligands mandipropamid and azinphos-ethyl. Experiments in Arabidopsis thaliana and Saccharomyces cerevisiae demonstrate the sensitive detection of banned organophosphate contaminants using living biosensors and the construction of multi-input/output genetic circuits. Our new modules enable ligand-programmable multi-channel CID systems for plant and eukaryotic synthetic biology that can empower new plant-based and microbe-based sensing modalities.
Topics: Abscisic Acid; Arabidopsis; Arabidopsis Proteins; Dimerization; Ligands; Membrane Transport Proteins
PubMed: 37872402
DOI: 10.1038/s41589-023-01447-7 -
The Science of the Total Environment Nov 2021The study aimed to assess the occurrence and the environmental risk of a group of 51 selected pesticides in the Guadiana Basin (a biodiversity hotspot, in the...
The study aimed to assess the occurrence and the environmental risk of a group of 51 selected pesticides in the Guadiana Basin (a biodiversity hotspot, in the Mediterranean). The most abundant pesticides were bentazone and 2,4-D, while terbuthylazine together with terbutryn constituted the most ubiquitous pesticides. Eighteen out of the 38 pesticides detected are no longer approved in Europe, and 5 of them are included in the list of priority substances. The risk assessment showed that azinphos ethyl, diflufenican, irganol, imidacloprid, and oxadiazon occurred occasionally, but always in concentrations above their respective ecotoxicological threshold value. Contrary, bentazone, terbuthylazine, and terbutryn presented a high risk in most of the sampled locations and periods. The site-specific risk assessment showed a spatial and temporal pattern, with a higher risk occurring mainly in intermittent streams, in the drought period. The presence of pesticides banned from the EU market since 2009 showed the importance of improving the monitoring process, to identify the main sources of pollution and the fate of these emerging compounds. The results showed the need of implementing actions to improve the sustainable use of pesticides in agricultural areas, working with farmers and management entities to reduce the contamination of aquatic ecosystems. Transboundary water governance is also required to solve potential transboundary contamination problems.
Topics: Ecosystem; Environmental Monitoring; Pesticides; Portugal; Risk Assessment; Rivers; Water Pollutants, Chemical
PubMed: 34214808
DOI: 10.1016/j.scitotenv.2021.148703 -
The Science of the Total Environment Nov 2020Water is an essential resource for all living organisms. The continuous and increasing use of pesticides in agricultural and urban activities results in the pollution of...
Improved fully automated method for the determination of medium to highly polar pesticides in surface and groundwater and application in two distinct agriculture-impacted areas.
Water is an essential resource for all living organisms. The continuous and increasing use of pesticides in agricultural and urban activities results in the pollution of water resources and represents an environmental risk. To control and reduce pesticide pollution, reliable multi-residue methods for the detection of these compounds in water are needed. In this context, the present work aimed at providing an analytical method for the simultaneous determination of trace levels of 51 target pesticides in water and applying it to the investigation of the target pesticides in two agriculture-impacted areas of interest. The method developed, based on an isotopic dilution approach and on-line solid-phase extraction-liquid chromatography-tandem mass spectrometry, is fast, simple, and to a large extent automated, and allows the analysis of most of the target compounds in compliance with European regulations. Application of the method to the analysis of selected water samples collected at the lowest stretches of the two largest river basins of Catalonia (NE Spain), Llobregat and Ter, revealed the presence of a wide suite of pesticides in the Llobregat basin, some of them at concentrations above the water quality standards (irgarol and dichlorvos) or the acceptable method detection limits (methiocarb, imidacloprid, and thiacloprid), and much cleaner waters in the Ter River basin. Risk assessment of the pesticide concentrations measured in the Llobregat River indicated high risk due to the presence of irgarol, dichlorvos, methiocarb, azinphos ethyl, imidacloprid, and diflufenican (hazard quotient (HQ) values>10), and moderate potential risk in the Ter River, associated to the occurrence of bentazone and irgarol (HQ > 1).
PubMed: 32736100
DOI: 10.1016/j.scitotenv.2020.140650 -
Journal of the Science of Food and... Apr 2020Pesticides are extensively used worldwide to control plant pathogens and prevent agricultural product damage. However, they can pollute the environment and endanger...
Hyphenated dispersive solid- and liquid-phase microextraction technique based on a hydrophobic deep eutectic solvent: application for trace analysis of pesticides in fruit juices.
BACKGROUND
Pesticides are extensively used worldwide to control plant pathogens and prevent agricultural product damage. However, they can pollute the environment and endanger human health. So far, a variety of sample preparation methods have been developed for the analysis of pesticide residues.
RESULTS
A hyphenated solid-liquid microextraction method based on a new adsorbent of magnetic graphene oxide functionalized by (3-glycidyloxypropyl)trimethoxysilane and a deep eutectic solvent (choline chloride/4-chlorophenol (1:2)) was developed for extraction/preconcentration of trace levels of pesticides. The sorbent was characterized using scanning electron microscopy, Fourier transform infrared spectroscopy, and vibrating sample magnetometry. In-syringe magnetic dispersive solid-phase extraction in tandem with dispersive liquid-liquid microextraction followed by gas chromatography was applied for the analysis of the selected pesticides. The main parameters governing sample preparation efficiency, including adsorbent dosage, desorption conditions, pH, extraction time, deep eutectic solvent volume, and salt concentration, were investigated. The linear ranges were 0.024-500 μg L with 0.9971-0.9999 linearity factor (R ). The limits of detection and quantification were 0.006-0.038 and 0.024-0.126 μg L , respectively. The relative standard deviations were 0.5-4.2% for intra-day analysis and 2.7-4.6% for inter-day analysis. Enrichment factors were in the range 210-540.
CONCLUSIONS
The method was successfully applied for the determination of malathion, heptachlor epoxide, endrin, dichlorodiphenyltrichloroethane, azinphos ethyl, cypermethrin, and deltamethrin in fruit juice samples (apple, pineapple, cherry, peach, and red and green grape juices) and the recoveries were within the range 71-115%. © 2020 Society of Chemical Industry.
Topics: Adsorption; Chromatography, Gas; Fruit and Vegetable Juices; Graphite; Liquid Phase Microextraction; Magnetic Phenomena; Pesticide Residues; Solid Phase Extraction; Solvents
PubMed: 31975389
DOI: 10.1002/jsfa.10279 -
Journal of Pharmaceutical and... Aug 2024Pesticides play an important role in forensic toxicology and are usually classified as a single class of chemicals. Despite their commonly perceived unity, pesticides...
Development and validation of a multi-substance method for routine analysis of pesticides in post-mortem samples by Ultra-High Performance Liquid Chromatography-Tandem Mass Spectrometry.
Pesticides play an important role in forensic toxicology and are usually classified as a single class of chemicals. Despite their commonly perceived unity, pesticides encompass a spectrum of compounds, including organophosphates, carbamates, pyrethroids or organochlorines, among others, each with varying degrees of toxicity. Pesticide analysis in post-mortem samples can be difficult due to the complexity of the samples and to the high toxicity of these compounds. The aim of this study was to develop and validate an easy to use, sensitive, and robust method, using ultra-performance liquid chromatography-tandem mass spectrometry to be incorporated in the routine flow for pesticide analysis in post-mortem blood samples. Described herein is a streamlined, expeditious, yet highly efficient method facilitating the screening, qualitative assessment, and quantitative confirmation of 15 pesticides, including acetamiprid, azinphos-ethyl, bendiocarb, carbofuran, chlorfenvinphos, dimethoate, imidaclopride, malathion, methiocarb, methomyl, parathion, pirimicarb, strychnine, tetrachlorvinphos, and thiacloprid in post-mortem blood, recognizing the pivotal role blood plays in forensic investigations. The developed method was linear from 10 to 200 ng/mL; limits of detection were between 1 and 10 ng/mL, depending on the compound; it was successfully evaluated a dilution ratio of 1-2, 5 and 10; and 8 substances showed maximum stability for the time interval studied. This UHPLC-MS/MS method is useful and a powerful tool in a toxicology lab because it is fast, simple, effective, and trustworthy. The results of this validation highlight the robustness of the analytical method, providing a valuable tool for the accurate and sensitive detection of pesticides in post-mortem blood. Poised for routine implementation, this method has already found success in suspected intoxication cases, promising to elevate the standards of forensic pesticide analysis.
Topics: Tandem Mass Spectrometry; Chromatography, High Pressure Liquid; Humans; Pesticides; Forensic Toxicology; Reproducibility of Results; Autopsy; Limit of Detection
PubMed: 38701535
DOI: 10.1016/j.jpba.2024.116176