Glufosinate-ammonium causes liver injury in zebrafish by blocking the Nrf2 pathway.

Glufosinate-ammonium (GLA) is a widely used herbicide, but less research has been done on its harmful effects on non-target organisms, especially aquatic organisms. In this study, 600 adult zebrafish were exposed to different concentration of GLA (0, 1.25, 2.5, 5, 10, and 20 mg/L) for 7 days, and the livers were dissected on the eighth day to examine the changes in liver structure, function, oxidative stress, inflammation, apoptosis, and Nrf2 pathway, and finally to clarify the mechanism of GLA induced liver injury in zebrafish. The levels of alanine aminotransferase, aspartate aminotransferase, reactive oxygen species, malondialdehyde, inflammatory factors (IL-6 and TNF-α), and caspase-3 gradually increased, while the levels of superoxide dismutase, catalase, glutathione, and glutathione peroxidase gradually decreased with the increase of GLA concentration. The Nrf2 pathway was activated at low concentrations (1.25-5 mg/L) and significantly inhibited at high concentrations (10 and 20 mg/L). These results suggested that GLA could cause oxidative stress, inflammation, and apoptosis in zebrafish liver. Therefore, GLA can cause liver injury in zebrafish, and at high concentrations, the inhibition of Nrf2 pathway is one of the important causes of liver injury.

Sulfadiazine and phosphinothricin selection systems optimised for the transformation of tobacco BY-2 cells.

KEY MESSAGE: We extended the applicability of the BY-2 cell line as a model by introducing two new selection systems. Our protocol provides guidelines for optimising Basta selection in other recalcitrant models. Tobacco BY-2 cell line is the most commonly used cytological model in plant research. It is uniform, can be simply treated by chemicals, synchronised and easily transformed. However, only a few selection systems are available that complicate advanced studies using multiple stacked transgenes and extensive gene editing. In our work, we adopted for BY-2 cell line two other selection systems: sulfadiazine and phosphinothricin (PPT, an active ingredient of Basta herbicide). We show that sulfadiazine can be used in a wide range of concentrations. It is suitable for co-transformation and subsequent double selection with kanamycin or hygromycin, which are standardly used for BY-2 transformation. We also have domesticated the sulfadiazine resistance for the user-friendly GoldenBraid cloning system. Compared to sulfadiazine, establishing selection on phosphinothricin was considerably more challenging. It did not work in any concentration of PPT with standardly cultured cells. Since the selection is based on blocking glutamine synthetase and consequent ammonium toxicity and deficiency of assimilated nitrogen, we tried to manipulate nitrogen availability. We found that the PPT selection reliably works only with nitrogen-starved cells with reduced nitrate reserves that are selected on a medium without ammonium nitrate. Both these adjustments prevent the release of large amounts of ammonium, which can toxify the entire culture in the case of standardly cultured cells. Since high nitrogen reserves can be a common feature of in vitro cultures grown on MS media, nitrogen starvation could be a key step in establishing phosphinothricin resistance in other plant models.

Prognostic value of neutrophil to lymphocyte ratio in the diagnosis of neurotoxicity after glufosinate ammonium poisoning.

Neurotoxicity related to glufosinate ammonium is known to occur after a latent period of 4-60 hr following ingestion of this herbicide. However, neurotoxicity is difficult to predict in the emergency department (ED) and only a few parameters are known to be useful to indicate development of neurotoxicity. Determination of a systemic inflammation parameter such as the neutrophil to lymphocyte ratio (NLR), is a rapid and simple method which was found to be a prognostic marker in various clinical conditions such as sepsis, cardiac disorders, stroke, and cancer. Therefore, the aim of this study was to determine whether the NLR might predict neurotoxicity and be used at ED to detect neurotoxicity induced following glufosinate ammonium poisoning in admitted patients. This retrospective observational study collected data from consecutive patients diagnosed with acute glufosinate ammonium poisoning between January 2005 and December 2020. The primary outcome was development of neurotoxicity following acute glufosinate ammonium poisoning. Out of the 72 patients selected 44 patients (61.1%) exhibited neurotoxic symptoms. Neurotoxicity appeared with an approximate latent period of 12 hr. The NLR was significantly higher in the group displaying neurotoxicity. Multivariable analysis showed that the NLR was significant in predicting neurotoxicity. The NLR was independently associated with neurotoxicity initiated by glufosinate ammonium. Therefore, the use of the NLR might help clinically to readily and rapidly predict development of neurotoxicity associated with glufosinate ammonium at the ED.

Exposure Impacts of Environmentally Relevant Concentrations of a Glufosinate Ammonium Herbicide Formulation on Larval Development and Thyroid Histology of Xenopus laevis.

Thyroid hormones play critical roles in body growth and development as well as reproduction. They also influence the activities of a wider variety of tissues and biological functions, such as osmoregulation, metabolism, and especially metamorphosis in organisms, such as frogs. These complex activities of thyroid hormones are prone to disruption by agricultural pesticides, often leading to modulation of growth and the reproductive system in particular. These substances include Glufosinate ammonium, Glyphosates, Imazapyr, Penoxsulam, and Diquat dibromide among other herbicides. In this study, the standardized Xenopus Metamorphosis Assay protocol was used to assess the potential thyroid-modulatory properties of the Glufosinate ammonium Basta formulation, at relevant environmental concentrations (0.05 mg/L, 0.15 mg/L, and 0.25 mg/L) for 21 days. The results showed that this formulation only reduced the hind-limb length among the morphological endpoints. Histological evaluation showed that the mean thyroid gland area and the mean thyroidal follicle epithelium height were significantly increased following 0.15 and 0.25 mg/L exposures. The present study confirmed that this Basta formulation interacts with the thyroid axis and therefore potentially pose health hazard to amphibian in particular and potentially metamorphic aquatic vertebrates. Furthermore, the result is a signal of inherent potential thyroid disrupting activities that must be further investigated and characterised in some of the aquatic herbicide formulations to safeguard the aquatic biodiversity.

[A case of glufosinate-ammonium poisoning in a patient with total gastrectomy].

Objective: To analyze the diagnosis and treatment of a patient with glufosinate-ammonium poisoning after total gastrectomy. Methods: The clinical data of a patient with oral glufosinate-ammonium poisoning after total gastrectomy in the First Affiliated Hospital of Nanjing Medical University in August 2020 were analyzed. Results: After total gastrectomy, the patient took about 200 ml of glufosinate-ammonium orally, and the plasma glufosinate-ammonium concentration was 816.8 ng/ml 6.5 h after poisoning. After symptomatic treatment such as promoting poison excretion, rehydration, anti infection and protecting important organs, the patient improved and discharged. Conclusion: The clinical manifestations of patients with glufosinate-ammonium poisoning after total gastrectomy are still mainly neurological symptoms, with delayed effect. Whether total gastrectomy will affect the distribution and toxic effect of the poison still needs further exploration.

[One case successfully rescued acute poisoning caused by misadministration of large amount of glufosinate].

Objective: To report a case of acute glufosinate-ammonium poisoning cause respiratory cardiac arrest and grass amine poisoning cases of successful rescue. Methods: The clinical data of a case of acute glufosinate-ammonium poisoning admitted to a third-class a hospital in April 2018 were analyzed and summarized. Results: The patient was poisoned by oral administration of a large amount of glufosinate-ammonium. Respiratory and cardiac arrest occurred during treatment and resuscitation was successful Later, the nervous system showed impaired function, The patients were treated with complete gastrointestinal cleansing, hemoperfusion, and the protection of important organs. Conclusion: For a large number of patients with oral glufosinate-ammonium poisoning, we should pay close attention to the damage of nervous system while taking active and conventional detoxification treatment.

Runoff of the herbicides triclopyr and glufosinate ammonium from oil palm plantation soil.

This study focused on the residue detection of the herbicides triclopyr and glufosinate ammonium in the runoff losses from the Tasik Chini oil palm plantation area and the Tasik Chini Lake under natural rainfall conditions in the Malaysian tropical environment. Triclopyr and glufosinate ammonium are post-emergence herbicides. Both herbicides were foliar-sprayed on 0.5 ha of oil palm plantation plots, which were individualized by an uneven slope of 10-15%. Samples were collected at 1, 3, 7, 15, 30, 45, 60, 90, and 120 days after treatment. The concentrations of both herbicides quickly diminished from those in the analyzed sample by the time of collection. The highest residue levels found in the field surface leachate were 0.031 (single dosage, triclopyr), 0.041 (single dosage, glufosinate ammonium), 0.017 (double dosage, triclopyr), and 0.037 µg/kg (double dosage, glufosinate ammonium). The chromatographic peaks were observed at "0" day treatment (2 h after herbicide application). From the applied active ingredients, the triclopyr and glufosinate losses were 0.025 and 0.055%, respectively. The experimental results showed that both herbicides are less potent than other herbicides in polluting water systems because of their short persistence and strong adsorption onto soil clay particles.

Resistance to glufosinate is proportional to phosphinothricin acetyltransferase expression and activity in LibertyLink(®) and WideStrike(®) cotton.

MAIN CONCLUSION: Insertion of the gene encoding phosphinothricin acetyltransferase (PAT) has resulted in cotton plants resistant to the herbicide glufosinate. However, the lower expression and commensurate reduction in PAT activity is a key factor in the low level of injury observed in the WideStrike(®) cotton and relatively high level of resistance observed in LibertyLink(®) cotton. LibertyLink(®) cotton cultivars are engineered for glufosinate resistance by overexpressing the bar gene that encodes phosphinothricin acetyltransferase (PAT), whereas the insect-resistant WideStrike(®) cultivars were obtained using the similar pat gene as a selectable marker. The latter cultivars carry some level of resistance to glufosinate which enticed certain farmers to select this herbicide for weed control with WideStrike(®) cotton. The potency of glufosinate on conventional FM 993, insect-resistant FM 975WS, and glufosinate-resistant IMACD 6001LL cotton cultivars was evaluated and contrasted to the relative levels of PAT expression and activity. Conventional cotton was sensitive to glufosinate. The single copy of the pat gene present in the insect-resistant cultivar resulted in very low RNA expression of the gene and undetectable PAT activity in in vitro assays. Nonetheless, the presence of this gene provided a good level of resistance to glufosinate in terms of visual injury and effect on photosynthetic electron transport. The injury is proportional to the amount of ammonia accumulation. The strong promoter associated with bar expression in the glufosinate-resistant cultivar led to high RNA expression levels and PAT activity which protected this cultivar from glufosinate injury. While the insect-resistant cultivar demonstrated a good level of resistance to glufosinate, its safety margin is lower than that of the glufosinate-resistant cultivar. Therefore, farmers should be extremely careful in using glufosinate on cultivars not expressly designed and commercialized as resistant to this herbicide.

Glufosinate aerogenic exposure induces glutamate and IL-1 receptor dependent lung inflammation.

Glufosinate-ammonium (GLA), the active component of an herbicide, is known to cause neurotoxicity. GLA shares structural analogy with glutamate. It is a powerful inhibitor of glutamine synthetase (GS) and may bind to glutamate receptors. Since these potentials targets of GLA are present in lung and immune cells, we asked whether airway exposure to GLA may cause lung inflammation in mice. A single GLA exposure (1 mg/kg) induced seizures and inflammatory cell recruitment in the broncho-alveolar space, and increased myeloperoxidase (MPO), inducible NO synthase (iNOS), interstitial inflammation and disruption of alveolar septae within 6-24 h. Interleukin 1ß (IL-1ß) was increased and lung inflammation depended on IL-1 receptor 1 (IL-1R1). We demonstrate that glutamate receptor pathway is central, since the N-methyl-D-aspartate (NMDA) receptor inhibitor MK-801 prevented GLA-induced lung inflammation. Chronic exposure (0.2 mg/kg 3× per week for 4 weeks) caused moderate lung inflammation and enhanced airway hyperreactivity with significant increased airway resistance. In conclusion, GLA aerosol exposure causes glutamate signalling and IL-1R-dependent pulmonary inflammation with airway hyperreactivity in mice.

Negative effects on the adaptive strategies of the lizards (Eremias argus) under starvation after exposure to Glufosinate-ammonium.

Herbicide exposure poses a higher risk to reptiles due to their frequent contact with soil. Besides, food restriction is also a common environmental pressure that can seriously affect the survival of reptiles. The adaptive strategies of reptiles in the face of emerging herbicide pollution and food shortage challenges are not yet known. Therefore, Eremias Argus (a kind of small reptile) was selected as the model to simulate the real scenario of food shortage in lizards, aiming to explore the comprehensive impact of glufosinate-ammonium (GLA: an emerging herbicide) and food restriction on lizards. The results revealed that lizards often regulate their physiological and biochemical activities through body thermal selection and tend to choose lower body temperature, reduce digestibility, and actively participate in fat energy mobilization to avoid oxidative damage in the state of hunger, finally in order to achieve homeostasis. However, herbicide GLA disrupted the lizards' efforts to resist the stress of food shortage and interfered with the normal thermoregulation and energy mobilization strategies of lizards facing starvation. The results of this study would improve our understanding of the impacts of Lizards under extreme stresses, help supplement reptile toxicology data and provide scientific basis for the risk assessment of herbicide GLA.

Glufosinate-ammonium increased nitrogen and phosphorus content in water and shaped microbial community in epiphytic biofilm of Hydrilla verticillata.

Glufosinate-ammonium (GLAM) can be released into adjacent water bodies with rainfall runoff and return water from farmland irrigation. However, impacts of GLAM on aquatic organisms remain unclear. In this study, changes in water quality, plant physiological parameters and epiphytic microbial community were investigated in wetlands with Hydrilla verticillata exposed to GLAM for 24 days. We found GLAM addition damaged cell and reduced chlorophyll a content in Hydrilla verticillata leaves, and increased ammonium and phosphorus in water (p < 0.001). The α-diversity increased in bacterial community but decreased in eukaryotic community with GLAM exposure. Neutral community models explained 62.3 % and 55.0 % of the variance in bacterial and eukaryotic communities, respectively. Many GLAM micro-biomarkers were obtained, including some clades from Proteobacteria, Bacteroidete, Actinobacteriota, Phragmoplastophyta, Annelida and Arthropoda. Redundancy analysis revealed that GLAM concentration was positively correlated to Flavobacterium, Gomphonema and Closterium but negatively to Methyloglobulus and Methylocystis. Network analysis revealed that 15 mg/L GLAM disturbed the interactions among phytoplankton, protozoa, metazoan and bacteria and reduced the stability of the microbial communities compared to 8 mg/L GLAM. GLAM shaped the nitrogen and phosphorus cycle related bacterial genes. This study highlights that herbicides are non-neglectable factors affecting the efficiency of aquatic ecological restoration in agricultural areas to control agricultural non-point source pollution.

Sensitive fluorescence detection of glyphosate and glufosinate ammonium pesticides by purine-hydrazone-Cu2+ complex.

Organophosphorus pesticides play an important role as broad-spectrum inactivating herbicides in agriculture. Developing a method for rapid and efficient organophosphorus pesticides detection is still urgent due to the increasing concern on food safety. An organo-probe (ZDA), synthesized by purine hydrazone derivative and 2,2'-dipyridylamine derivative, was applied in sensitive recognition of Cu2+ with detection limit of 300 nM. Mechanism study via density functional theory (DFT) and job's plot experiment revealed that ZDA and Cu2+ ions form a 1:2 complex quenching the fluorescence emission. Moreover, this fluorescent complex ZDA-Cu2+ was applicable for detecting glyphosate and glufosinate ammonium following fluorescence enhancement mechanism, with detection limits of 11.26 nM and 11.5 nM, respectively. Meanwhile, ZDA-Cu2+ was effective and sensitive when it is used for pesticide detection, reaching the maximum value and stabilizing in 1 min. Finally, the ZDA-Cu2+ probe could also be tolerated in cell assay environment, implying potential bio-application.

Trimethylation Enhancement Using Diazomethane (TrEnDi) Enables Enhanced Detection of Glufosinate and 3-(Methylphosphinico)propionic Acid from Complex Canola Samples.

Over the past century, agriculture practices have transitioned from manual cultivation to the use of an array of chemical herbicides for weed control including phosphinothricin, or glufosinate (GLUF). Consequently, the potential for long-term residual GLUF exposure in the food chain has increased, highlighting the need for improved analytical strategies for its detection, as well as the detection of its main breakdown product 3-(methylphosphinico)propionic acid (MPPA). Chemical derivatization strategies have been developed to improve the detection of GLUF and MPPA via liquid chromatography tandem mass spectrometry analyses. Herein, we employ trimethylation enhancement using diazomethane (TrEnDi) for the first time as a means to confer analytical advantages via quantitatively derivatizing these analytes into permethylated GLUF ([GLUFTr]+) and MPPA ([MPPATr+H]+). Comparing [GLUFTr]+ and [MPPATr+H]+ to underivatized counterparts, TrEnDi yields 2.8-fold and 1.7-fold improvements in reversed-phase chromatographic retention, respectively, while MS-based sensitivity is enhanced 4.1-fold and 11.0-fold, respectively. Successful analyte derivatization (with >99% yields) was further demonstrated on a commercial herbicide solution imparting consistent analytical enhancements. To investigate the benefits of TrEnDi in a bona fide agricultural scenario, simple aqueous extractions from distinct parts of field-grown canola plants were performed to quantify GLUF and MPPA before and after TrEnDi derivatization. In their underivatized forms, GLUF and MPPA were undetectable in all field samples, whereas [GLUFTr]+ and [MPPATr+H]+ were readily quantifiable using the same analysis conditions. Our results demonstrate that TrEnDi continues to be a useful tool to enhance the analytical characteristics of organic molecules that are traditionally difficult to detect.

Glufosinate herbicide intoxication causing unconsciousness, convulsion, and 6th cranial nerve palsy.

Although glufosinate ammonium herbicides are considered safe when used properly, ingestion of the undiluted form can cause grave outcomes. Recently, we treated a 34-yr-old man who ingested glufosinate ammonium herbicide. In the course of treatment, the patient developed apnea, mental deterioration, and sixth cranial nerve palsy; he has since been discharged with full recovery after intensive care. This case report describes the clinical features of glufosinate intoxication with a focus on sixth cranial nerve palsy. Our observation suggests that neurologic manifestations after ingestion of a "low-grade toxicity herbicide" are variable and more complex than that was previously considered.

Effect of metabolic inhibitors on growth and carotenoid production in Dunaliella bardawil.

Dunaliella bardawil, a green alga accumulates high amount of ß-carotene under stress conditions. This organism has been exploited for ß-carotene at industrial scale. In the present work, various metabolic inhibitors like diphenylamine (DPA), nicotine, basta, glyphosate, DCMU [3-(3',4'-dichlophenyl)-1,1-dimethylurea] and caffeine were used in autotrophic medium, to understand their influence on carotenoid biosynthesis. The results indicated that these metabolic inhibitors influenced the production of carotenoids like wise, DPA and basta increased the contents of ß-carotene (1.7 fold), glyphosate and DCMU for lutein (2.4 and 2 fold) caffeine for biomass yields (1.1 fold), while nicotine decreased the biomass yield (3.6 fold), ß-carotene (2 fold) and lutein (10.5 fold).

The trend of ammonia levels in patients with glufosinate ammonium poisoning with respect to neurotoxicity.

Since glufosinate irreversibly inhibits glutamine synthetase, leading to intracellular accumulation of ammonia, hyperammonemia is considered one of the main mechanisms of glufosinate ammonium toxicity in humans. However, whether hyperammonemia causes neurotoxicity has not yet been studied. Therefore, the purpose of this study was to determine whether the serum ammonia level is elevated before the development of neurotoxicity. In this retrospective observational study, we analyzed data from consecutive patients diagnosed with acute glufosinate ammonium poisoning. The primary outcome was the development of neurotoxicity following the poisoning. Patients who developed neurotoxicity were characterized by higher initial ammonia levels compared to patients without neurotoxicity (121.0 µg/dL [87.0; 141.0] vs 83.0 µg/dL [65.0; 119.0], p < 0.01). However, there was no increase in ammonia levels over time in both the asymptomatic and neurotoxicity groups when serial serum ammonia levels were examined from emergency department admission to hospital discharge. In addition, there was no statistically significant difference between the peak ammonia levels in the asymptomatic group and the peak ammonia levels before symptom onset in the neurotoxicity group (135.0 µg/dL [109.0; 158.0] vs 144.0 µg/dL [120.0; 189.0], p = 0.15). Following the onset of neurotoxicity, the serum ammonia level increased significantly (125.0 [111.0; 151.0] µg/dL to 148.0 [118.0; 183.0] µg/dL, p < 0.01). In conclusion, hyperammonemia cannot be assumed as the cause of neurotoxicity in glufosinate ammonium poisoning and further research is needed to examine the exact mechanism of GA poisoning.

Insights into the effects of sublethal doses of pesticides glufosinate-ammonium and sulfoxaflor on honey bee health.

Insect pollinators are threatened worldwide, being the exposure to multiple pesticides one of the most important stressor. The herbicide Glyphosate and the insecticide Imidacloprid are among the most used pesticides worldwide, although different studies evidenced their detrimental effects on non-target organisms. The emergence of glyphosate-resistant weeds and the recent ban of imidacloprid in Europe due to safety concerns, has prompted their replacement by new molecules, such as glufosinate-ammonium (GA) and sulfoxaflor (S). GA is a broad-spectrum and non-selective herbicide that inhibits a key enzyme in the metabolism of nitrogen, causing accumulation of lethal levels of ammonia; while sulfoxaflor is an agonist at insect nicotinic acetylcholine receptors (nAChRs) and generates excitatory responses including tremors, paralysis and mortality. Although those molecules are being increasingly used for crop protection, little is known about their effects on non-target organisms. In this study we assessed the impact of chronic and acute exposure to sublethal doses of GA and S on honey bee gut microbiota, immunity and survival. We found GA significantly reduced the number of gut bacteria, and decreased the expression of glucose oxidase, a marker of social immunity. On the other hand, S significantly increased the number of gut bacteria altering the microbiota composition, decreased the expression of lysozyme and increased the expression of hymenoptaecin. These alterations in gut microbiota and immunocompetence may lead to an increased susceptibility to pathogens. Finally, both pesticides shortened honey bee survival and increased the risk of death. Those results evidence the negative impact of GA and S on honey bees, even at single exposition to a low dose, and provide useful information to the understanding of pollinators decline.

Sub-acute toxicity of the herbicide glufosinate-ammonium exposure in adult red swamp crayfish (Procambarus clarkii).

Glufosinateammonium (GLA) is one of the most widely used agricultural herbicides. It is frequently detected in surface waters near farmland and may pose a risk to non-target aquatic species. This study aimed to explore the toxicity of subacute GLA exposure in crayfish. Adult red swamp crayfish were exposed to GLA (0, 1, 10, and 100 mg/L) for 21 days. Bioaccumulation, oxidative stress, nonspecific immunity, and the expression of genes encoding xenobiotic detoxification-related enzymes were examined. The results showed GLA accumulation and hepatopancreatic histopathological changes (dilation of hepatic tubules and vacuolation of hepatocytes) in the exposed crayfish. GLA exposure induced ROS production, inhibited glutathione expression, and catalase activity in the crayfish hepatopancreas, as well as inhibited immunoenzyme expression (acid phosphatase, alkaline phosphatase, and lysozyme) in the hemolymph. In addition, the total hemocyte number decreased, and the proportion of hemocyte subsets changed significantly. Superoxide dismutase first increased and then decreased with increasing GLA dosage. GLA promoted the expression of biotransformation enzymes (cypb5, gst) in the hepatopancreas. Our results suggest that subacute GLA exposure caused structural damage to the hepatopancreatic tissue and decreased antioxidant capacity and non-specific immunity in crayfish. These findings provide insight into the toxicity of herbicides on non-target organisms.

Sensing of organophosphorus pesticides by fluorescent complexes based on purine-hydrazone receptor and copper (II) and its application in living-cells imaging.

In this study, we used purine hydrazone derivatives and coumarin aldehyde to synthesize a novel fluorescent sensor (EDTP) by Schiff base reaction, which exhibited significant selective fluorescence quenching of Cu2+, and a distinct change from brilliant yellow to red is present along with the solution color. The detection limit of EDTP for Cu2+ was 109.52 nM. Job's plot experiment, density flooding theory (DFT) and 1H NMR titration experiments revealed the possible binding mechanism of EDTP to Cu2+, the probe EDTP could achieve highly detection of Cu2+ through forming a 1:1 complex. Additionally, this new fluorescent sensor EDTP-Cu2+ can be further applied in the rapid and selective detection of pesticide residues in solutions. When the EDTP-Cu2+ system was subsequently exposed to organophosphorus pesticides (glyphosate and glufosinate-ammonium), it was observed that the fluorescence was recovered and accompanied by a red to yellow color change. This may be attributed to the strong chelation of glyphosate and glufosinate-ammonium with Cu2+, leading to the dissociation of the EDTP-Cu2+ system and thus triggering the fluorescence recovery effect. The detection limits of the EDTP-Cu2+ system is 2.48 nM for glyphosate and 17.23 nM for glufosinate-ammonium, respectively. Finally, the developed sensor system has been successfully utilized image glyphosate and glufosinate-ammonium fluorescence in living cells. Purine fluorescence probes are a potential fluorescent probe for the detection of metal ions and pesticides due to their good characteristics. This study opens up a new way for the detection of fluorescent probes in pesticides.

Comparison of the chronic and multigenerational toxicity of racemic glufosinate and l-glufosinate to Caenorhabditis elegans at environmental concentrations.

Glufosinate-ammonium, the second largest transgene crop resistant herbicide, is classified as a mobile persistent pollutant by the U.S. Environmental Protection Agencybecause of its slow decomposition and easy mobile transfer in a water environment. The chronic and multigeneration toxicity of this compound to environmental organisms are alarming. In this study, racemic glufosinate-ammonium and the effective isomer, l-glufosinate-ammonium, were used as the test agents. The developmental, neurotoxic and reproductive toxicities of Caenorhabditis elegans to their parents and progeny were studied by continuous exposure in water at concentrations of 0.1, 1, 10 and 100 µg/L. The causes of toxicity differences were analysed from oxidative stress and transcription levels. Through oxidative stress of C. elegans, racemic glufosinate-ammonium and l-glufosinate-ammonium both mediated the developmental toxicity (shortened developmental cycle, reduced body length and width, promoted ageingand decreased longevity), neurotoxicity (inhibited head swinging, body bending frequency and acetylcholinesterase [AchE] activity) and reproductive toxicity (significant reductions in the number of eggs and offspring in vivo and induced apoptosis of gonadal cells). These phenomena caused oxidative damage (protein and membrane lipid peroxidation) and further induced apoptosis. The changes in various indicators caused by racemic glufosinate-ammonium exposure were more significant than those caused by l-glufosinate-ammonium exposure, and the reproduction-related indicators were more significant than the developmental and neurological indicators. A continuous accumulation of toxicity was observed after multiple generations of continuous exposure. These research results provide a data reference for the ecotoxicological evaluation and risk assessment of glufosinate-ammonium and contribute to the revision and improvement of the related environmental policies of glufosinate-ammonium.