Glyphosate: Its Environmental Persistence and Impact on Crop Health and Nutrition

Metabolomics insights of conventional and organic tempe during in vitro digestion and their antioxidant properties and cytotoxicity in HCT-116 cells

Tempe, a fermented soybean food rich in polyphenols including isoflavones, is valued for its health benefits, notably its antioxidants. Concerns about glyphosate residues in crops have led to increased demand for organic soy products, including tempe. The study aimed to investigate the metabolomic profiles of tempe and its bioactive potentials prior to and following in vitro simulated gastrointestinal digestion. Conventional soybean (CS), conventional tempe (CT), conventional tempe digesta (CTD), organic soybean (OS), organic tempe (OT) and organic tempe digesta (OTD) were analysed for various assays. The study observed a significant decrease in the total phenolic and flavonoid levels for conventional and organic samples in tempe extracts (CT, OT) compared to tempe digesta (CTD, OTD). Organic tempe digesta has a higher total phenolic content (CTD = 22.55 µg GAE/g, OTD = 41.36 µg GAE/g) and flavonoid content (CTD = 4.64 µg QE/g, OTD = 10.06 µg QE/g) compared to conventional tempe digesta. However, there is a significant difference in the bioaccessibility of phenolic (CT = 74.77 %, OT = 59.20 %) and flavonoid (CT = 49.4 %, OT = 57.52 %) in both organic and conventional tempe. Tempe consistently surpasses soybean in antioxidant assays such as DPPH, ABTS, and FRAP. Organic tempe digesta exhibits the most elevated levels of antioxidants. Using GNPS and the SIRIUS database, 34 metabolites were annotated according to the criteria of having a VIP score > 1.5, a log2(FC) > 1, and a p-value < 0.05. From the list, 26 metabolites demonstrated a positive correlation with antioxidant activity, DPPH, and FRAP. Molecular networking enables the visualization of 12 prominent isoflavones, namely daidzein, daidzin, genistein, genistin, glycitein, glycitin, 6″-O-malonyldaidzin, 6″-O-acetylgenistin, 6″-O-acetyldaidzin, and 7,8,4'-trihydroxyisoflavone. Interestingly, aglycone isoflavones are abundant in organic tempe digesta while glycoside isoflavones are abundant in organic and conventional soybeans. Overall, the findings indicate that tempe digesta exhibits distinct metabolic patterns and bioactive potentials.

Effects of biochar and compost on the abundant and rare microbial communities assembly and multifunctionality in pesticide-contaminated soil under freeze‒thaw cycles

Biochar and compost are effective ways to improve soil quality and reduce pesticide pollution. However, the effects of them on the abundant and rare microbial communities in freeze‒thaw soil need to be further clarified. Therefore, this study took biochar, compost, and their combination as examples to explore their effects on the abundant and rare microbial communities and multifunctionality in glyphosate, imidacloprid and pyraclostrobin contaminated soil under freeze‒thaw cycles. We found that freeze‒thaw cycles enhanced the functional groups and surface aromaticity of biochar and compost, thereby improving the adsorption capacity. Biochar and compost reduced the concentration and half-life of three pesticides and enhanced the degradation function of rare taxa in soil. Biochar and compost improved the structure composition and co-occurrence relationship of abundant and rare taxa. Meanwhile, the assembly processes of abundant and rare sub-communities were mainly driven by stochastic processes and the Combined treatment promoted the transition from dispersal limitation to homogenizing dispersal and homogeneous selection. Moreover, the Combined treatment significantly improved the multifunctionality before and after freezing and thawing by increasing the diversity of rare taxa and assembly processes. The results provide new insights for farmland soil remediation in seasonal frozen areas, especially the soil functional cycle of abundant and rare microorganisms.

The systemic herbicide glyphosate affects the sporulation dynamics of Rhizophagus species more severely than mechanical defoliation or the contact herbicide diquat

Arbuscular mycorrhizal fungi (AMF) are totally dependent on a suitable host plant for their carbon resources. Here, we investigated under in vitro conditions, the impact of defoliation practices, i.e., mechanical defoliation or chemical defoliation with a contact herbicide (Reglone®, containing the active ingredient diquat) or systemic herbicide (RoundUp®, containing the active ingredient glyphosate), on the dynamics of spore production of Rhizophagus irregularis and Rhizophagus intraradices associated with Solanum tuberosum and/or Medicago truncatula. Glyphosate affected the spore production rate more rapidly and severely than diquat or mechanical defoliation. We hypothesize that this effect was related to disruption of the C metabolism in the whole plant combined with a possible direct effect of glyphosate on the fungus within the roots and/or perhaps in soil via the release of this active ingredient from decaying roots. No glyphosate could be detected in the roots due to technical constraints, while its release from the roots in the medium corresponded to 0.11% of the active ingredient applied to the leaves. The three defoliation practices strongly affected root colonization, compared to the non-defoliated plants. However, the amount of glyphosate released into the medium did not affect spore germination and germ tube growth. These results suggest that the effects of defoliation on the dynamics of spore production are mainly indirect via an impact on the plant, and that the effect is faster and more marked with the glyphosate-formulation, possibly via a direct effect on the fungus in the roots and more unlikely on spore germination.

Effects of the glyphosate-based herbicide roundup on C. elegans and S. cerevisiae mortality, reproduction, and transcription fidelity

Glyphosate-based weed killers such as Roundup have been implicated in detrimental effects on single- and multicellular eukaryotic model organism health and longevity. However, the mode(s) of action for these effects are currently unknown. In this study, we investigate the impact of exposure to Roundup on two model organisms: Saccharomyces cerevisiae and Caenorhabditis elegans and test the hypothesis that exposure to Roundup decreases transcription fidelity. Population growth assays and motility assays were performed in order to determine the phenotypic effects of Roundup exposure. We also used Rolling-Circle Amplification RNA sequencing to quantify the impact of exposure to Roundup on transcription fidelity in these two model organisms. Our results show that exposure to the glyphosate-based herbicide Roundup increases mortality, reduces reproduction, and increases transcription error rates in C. elegans and S. cerevisiae. We suggest that these effects may be due in part to the involvement of inflammation and oxidative stress, conditions which may also contribute to increases in transcription error rates.

Centering Amah Mutsun voices in the analysis of a culturally important, fire-managed coastal grassland

Indigenous communities throughout California, USA, are increasingly advocating for and practicing cultural fire stewardship, leading to a host of social, cultural, and ecological benefits. Simultaneously, state agencies are recognizing the importance of controlled burning and cultural fire as a means of reducing the risk of severe wildfire while benefiting fire-adapted ecosystems. However, much of the current research on the impacts of controlled burning ignores the cultural importance of these ecosystems, and risks further marginalizing Indigenous knowledge systems. Our work adds a critical Indigenous perspective to the study of controlled burning in California's unique coastal grasslands, one of the most biodiverse and endangered ecosystems in the country. In this study, we partnered with the Amah Mutsun Tribal Band to investigate how the abundance and occurrence of shrubs, cultural plants, and invasive plants differed among three adjacent coastal grasslands with varying fire histories. These three sites are emblematic of the state's diverging approaches to grassland management: fire suppression, fire suppression followed by wildfire, and an exceedingly rare example of a grassland that has been repeatedly burned approximately every 2 years for more than 30 years. We found that Danthonia californica was significantly more abundant on the burned sites, whereas all included shrub species (Baccharis pilularis, Frangula californica, and Rubus ursinus) were significantly more abundant on the site with no recorded fire, results that have important implications for future cultural revitalization efforts and the loss of coastal grasslands to shrub encroachment. In addition to conducting a culturally relevant vegetation survey, we used Sentinel-2 satellite imagery to compare the relative severities of the two most recent fire events within the study area. Critically, we used interviews with Amah Mutsun tribal members to contextualize the results of our vegetation survey and remote sensing analysis, and to investigate how cultural burning contrasts from typical Western fire management approaches in this region. Our study is a novel example of how interviews, field data, and satellite imagery can be combined to gain a deeper ecological and cultural understanding of fire in California's endangered coastal grasslands.

Neuroglycome alterations of hippocampus and prefrontal cortex of juvenile rats chronically exposed to glyphosate-based herbicide

Introduction

Glyphosate-based herbicides (GBHs) have been shown to have significant neurotoxic effects, affecting both the structure and function of the brain, and potentially contributing to the development of neurodegenerative disorders. Despite the known importance of glycosylation in disease progression, the glycome profile of systems exposed to GBH has not been thoroughly investigated.

Methods

In this study, we conducted a comprehensive glycomic profiling using LC-MS/MS, on the hippocampus and prefrontal cortex (PFC) of juvenile rats exposed to GBH orally, aiming to identify glyco-signature aberrations after herbicide exposure.

Results

We observed changes in the glycome profile, particularly in fucosylated, high mannose, and sialofucosylated N-glycans, which may be triggered by GBH exposure. Moreover, we found major significant differences in the N-glycan profiles between the GBH-exposed group and the control group when analyzing each gender independently, in contrast to the analysis that included both genders. Notably, gender differences in the behavioral test of object recognition showed a decreased performance in female animals exposed to GBH compared to controls (p < 0.05), while normal behavior was recorded in GBH-exposed male rats (p > 0.05).

Conclusion

These findings suggest that glycans may play a role in the neurotoxic effect caused by GBH. The result suggests that gender variation may influence the response to GBH exposure, with potential implications for disease progression and specifically the neurotoxic effects of GBHs. Understanding these gender-specific responses could enhance knowledge of the mechanisms underlying GBH-induced toxicity and its impact on brain health. Overall, our study represents the first detailed analysis of N-glycome profiles in the hippocampus and PFC of rats chronically exposed to GBH. The observed alterations in the expression of N-glycan structures suggest a potential neurotoxic effect associated with chronic GBH exposure, highlighting the importance of further research in this area.

The impact of the herbicide glyphosate and its metabolites AMPA and MPA on the metabolism and functions of human blood neutrophils and their sex-dependent effects on reactive oxygen species and CXCL8/IL-8 production

Significant levels of glyphosate, the world's most widely used herbicide, and its primary metabolites, AMPA and MPA, are detected in various human organs and body fluids, including blood. Several studies have associated the presence of glyphosate in humans with health problems, and effects on immune cells and their functions have been reported. However, the impact of this molecule and its metabolites on neutrophils, the most abundant leukocytes in the human bloodstream, is still poorly documented. We isolated neutrophils from human donor blood and investigated the effects of exposure to glyphosate, AMPA, and MPA on viability, energy metabolism, and essential antimicrobial functions in vitro. We observed that neutrophil viability was unaffected at the blood-relevant average concentrations of the general population and exposed workers, as well as at higher intoxication concentrations. Neutrophil energy metabolism was also not altered following exposure to the chemicals. However, while phagocytosis was unaffected, reactive oxygen species generation and CXCL8/IL-8 production were altered by exposure to the molecules. Alterations in function following exposure to glyphosate and metabolites differed according to the sex of the donors, which could be linked to glyphosate's known role as an endocrine disruptor. While ROS generation was increased in both sexes, male neutrophils exposed to glyphosate had increased intracellular production of CXCL8/IL-8, with no effect on female neutrophils. Conversely, exposure to the metabolites AMPA and MPA decreased extracellular production of this chemokine only in female neutrophils, with MPA also increasing intracellular production in male cells exposed to the chemoattractant N-formyl-methionine-leucyl-phenylalanine. Our study highlights the effects of glyphosate and its metabolites on the antimicrobial functions of neutrophils, which could be associated with health problems as future studies provide a better understanding of the risks associated with glyphosate use. Advances in knowledge will enable better and potentially stricter regulations to protect the public.

Changes in the proteome of Apis mellifera acutely exposed to sublethal dosage of glyphosate and imidacloprid

Uncontrolled use of pesticides has caused a dramatic reduction in the number of pollinators, including bees. Studies on the effects of pesticides on bees have reported effects on both metabolic and neurological levels under chronic exposure. In this study, variations in the differential expression of head and thorax-abdomen proteins in Africanized A. mellifera bees treated acutely with sublethal doses of glyphosate and imidacloprid were studied using a proteomic approach. A total of 92 proteins were detected, 49 of which were differentially expressed compared to those in the control group (47 downregulated and 2 upregulated). Protein interaction networks with differential protein expression ratios suggested that acute exposure of A. mellifera to sublethal doses of glyphosate could cause head damage, which is mainly associated with behavior and metabolism. Simultaneously, imidacloprid can cause damage associated with metabolism as well as, neuronal damage, cellular stress, and impairment of the detoxification system. Regarding the thorax-abdomen fractions, glyphosate could lead to cytoskeleton reorganization and a reduction in defense mechanisms, whereas imidacloprid could affect the coordination and impairment of the oxidative stress response.

Glyphosate resistance and biodegradation by Burkholderia cenocepacia CEIB S5-2

Glyphosate is a broad spectrum and non-selective herbicide employed to control different weeds in agricultural and urban zones and to facilitate the harvest of various crops. Currently, glyphosate-based formulations are the most employed herbicides in agriculture worldwide. Extensive use of glyphosate has been related to environmental pollution events and adverse effects on non-target organisms, including humans. Reducing the presence of glyphosate in the environment and its potential adverse effects requires the development of remediation and treatment alternatives. Bioremediation with microorganisms has been proposed as a feasible alternative for treating glyphosate pollution. The present study reports the glyphosate resistance profile and degradation capacity of the bacterial strain Burkholderia cenocepacia CEIB S5-2, isolated from an agricultural field in Morelos-México. According to the agar plates and the liquid media inhibition assays, the bacterial strain can resist glyphosate exposure at high concentrations, 2000 mg·L-1. In the degradation assays, the bacterial strain was capable of fast degrading glyphosate (50 mg·L-1) and the primary degradation metabolite aminomethylphosphonic acid (AMPA) in just eight hours. The analysis of the genomic data of B. cenocepacia CEIB S5-2 revealed the presence of genes that encode enzymes implicated in glyphosate biodegradation through the two metabolic pathways reported, sarcosine and AMPA. This investigation provides novel information about the potential of species of the genus Burkholderia in the degradation of the herbicide glyphosate and its main degradation metabolite (AMPA). Furthermore, the analysis of genomic information allowed us to propose for the first time a metabolic route related to the degradation of glyphosate in this bacterial group. According to the findings of this study, B. cenocepacia CEIB S5-2 displays a great glyphosate biodegradation capability and has the potential to be implemented in glyphosate bioremediation approaches.

Regional evaluation of glyphosate pollution in the minor irrigation network

Due to its low cost, its ease of use and to the "mild action" declared for long time by the Control and Approval Agencies towards it, the herbicide Glyphosate, is one of the currently best-selling and most-used agricultural products worldwide. In this work, we evaluated the presence and spread of Glyphosate in the Po River Basin (Northern Italy), one of the regions with the most intensified agriculture in Europe and where, by now for decades, a strong and general loss of aquatic biodiversity is observed. In order to carry out a more precise study of the real presence of this herbicide in the waters, samples were collected from the minor water network for two consecutive years, starting in 2022, at an interval time coinciding with those of the spring and summer crop treatments. In contrast to the sampling strategies generally adopted by Environmental Protection Agencies, a more focused sampling strategy was adopted to highlight the possible high concentrations in minor watercourses in direct contact with cultivated fields. Finally, we investigated the possible consequences that the higher amounts of Glyphosate found in our monitoring activities can have on stress reactions in plant (Groenlandia densa) and animal (Daphnia magna) In all the monitoring campaigns we detected exceeding European Environmental Quality Standard - EQS limits (0.1 μg/L) values. Furthermore, in some intensively agricultural areas, concentrations reached hundreds of μg/L, with the highest peaks during spring. In G. densa and D. magna, the exposition to increasing doses of herbicide showed a clear response linked to metabolic stress. Overall, our results highlight how, after several decades of its use, the Glyphosate use efficiency is still too low, leading to economic losses for the farm and to strong impacts on ecosystem health. Current EU policy indications call for an agroecological approach necessary to find alternatives to chemical weed control, which farms can develop in different contexts in order to achieve the sustainability goals set by the Farm to Fork strategy.

Unusual redox stability of pentavalent uranium with hetero-bifunctional phosphonocarboxylate: insight into aqueous speciation

The +5 state is an unusual oxidation state of uranium due to its instability in the aqueous phase. As a result, gaining information about its aqueous speciation is extremely difficult. The present work is an attempt in that direction and it provides insight into the existence of a new pentavalent species in the presence of hetero-bifunctional phosphonocarboxylate (PC) chelators, other than the carbonate ion, in the aqueous medium. The aqueous chemistry of pentavalent uranium species with three environmentally relevant PCs was probed using electrochemical and DFT methods to understand the redox energy and kinetics of conversion of the U(VI)/U(V) couple, stability, structure, stoichiometry, binding modes, etc. Interestingly, pentavalent uranium complexes with PCs are quite persistent over a wide range of pH starting from acidic to alkaline conditions. The PC chelators block the cation-cation interaction (CCI) of U(V) through strong hetero-bidentate chelation and intermolecular hydrogen bonding (IMHB) interactions which stabilize the pentavalent metal ion against disproportionation. For uranyl species in the presence of PCs, acting as chelators, CV plots were obtained at varying pH values from 2 to 8. The obtained results indicate an irreversible single redox peak involving U(VI) to U(V) conversion and association of a coupled chemical reaction with the electron transfer step. ESI-MS studies were performed to understand the speciation effect on the U(VI)/U(V) redox couple with varying pH. Speciation modelling of U(V) with the PC ligands was carried out, which indicated that the U(V) is redox stable in nearly 47% of the pH region in the presence of the PCs as compared to the carboxylate-based chelators. The free energy and reduction potential of the U(V) complexes and the reduction free energy and disproportionation free energy for the U(VI)/U(V) couple were determined by DFT computations in the presence of the PCs. In situ spectroelectrochemical spectra were recorded to provide evidence for the existence of U(V) species with PCs in the aqueous medium and to acquire its absorption spectra. The present study is highly significant for understanding the coordination chemistry of pentavalent uranium species, accurate modelling of uranium, and isolation of U(V).

Toxicity of glyphosate to animals: A meta-analytical approach

Glyphosate (GLY)-based herbicides (GBHs) are the most commonly applied pesticide worldwide, and non-target organisms (e.g., animals) are now regularly exposed to GLY and GBHs due to the accumulation of these chemicals in many environments. Although GLY/GBH was previously considered to be non-toxic, growing evidence indicates that GLY/GBH negatively affects some animal taxa. However, there has been no systematic analysis quantifying its toxicity to animals. Therefore, we used a meta-analytical approach to determine whether there is a demonstrable effect of GLY/GBH toxicity across animals. We further addressed whether the effects of GLY/GBH vary due to (1) taxon (invertebrate vs. vertebrate), (2) habitat (aquatic vs. terrestrial), (3) type of biological response (behavior vs. physiology vs. survival), and (4) dosage or concentration of GLY/GBH. Using this approach, we also determined whether adjuvants (e.g., surfactants) in commercial formulations of GBHs increased toxicity for animals relative to exposure to GLY alone. We analyzed 1282 observations from 121 articles. We conclude that GLY is generally sub-lethally toxic for animals, particularly for animals in aquatic or marine habitats, and that toxicity did not exhibit dose-dependency. Yet, our analyses detected evidence for widespread publication bias so we encourage continued experimental investigations to better understand factors influencing GLY/GBH toxicity to animals.

Modeling pesticides and ecotoxicological risk assessment in an intermittent river using SWAT

The present work aimed to predict the fate of two pesticides, copper (Cu) and glyphosate in a Mediterranean basin with an intermittent river and to assess the ecotoxicological risk related to their presence in water bodies coupling field measurements of streamflow and pesticide concentrations, and an eco-hydrological model. The Soil and Water Assessment Tool (SWAT) model was calibrated and, subsequently used to assess predicted environmental concentrations of pesticides in surface waters. The ecotoxicological risk related to the presence of Cu and glyphosate in surface water was assessed at the reach scale by using the Toxicity to Exposure Ratio approach (TER). Measurements of glyphosate concentrations (< 0.5 μg l-1) exceeded the maximum European threshold of environmental quality standards for pesticides (EQS) of 0.1 μg l-1. High concentrations of glyphosate were predicted in the wet season and in September, when glyphosate is mostly used in vineyards and olive grove productions. Acute risk (TER < 100) associated with the presence of glyphosate was detected for several reaches. High concentrations of Cu (< 6.5 μg l-1), mainly used as a fungicide in vineyards, were predicted in several river reaches. The results of the ecotoxicological risk assessment revealed that November and January were the critical months during which most of the river reaches showed a chronic risk associated with the presence of Cu.

Low-background interference detection of glyphosate, glufosinate, and AMPA in foods using UPLC-MS/MS without derivatization

The abuse of herbicides has emerged as a great threat to food security. Herein, a low-background interference detection method based on UPLC-MS was developed for the simultaneous determination of glufosinate, glyphosate, and its metabolite aminomethylphosphonic acid (AMPA) in foods. Initially, this study proposed a simple and rapid pretreatment method, utilizing water extraction and PRiME HLB purification to isolate glyphosate, glufosinate, and AMPA from food samples. After the optimization of pretreatment conditions, the processed samples are then analyzed directly by ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS) without pre-column derivatization. The method can effectively reduce interference from by-products of pre-column derivatization and background substrates of food sample, showing low matrix effects (ME) ranging from - 24.83 to 32.10%. Subsequently, the method has been validated by 13 kinds of food samples. The recoveries of the three herbicides in the food samples range from 84.2 to 115.6%. The limit of detection (LOD) is lower to 0.073 mg/kg, 0.017 mg/kg, and 0.037 mg/kg, respectively. Moreover, the method shows an excellent reproducibility with relative standard deviations (RSD) within 16.9%. Thus, the method can provide high trueness, reproducibility, sensitivity, and interference-free detection to ensure human health safety.

Elucidation of the role of metals in the adsorption and photodegradation of herbicides by metal-organic frameworks

Here, four MOFs, namely Sc-TBAPy, Al-TBAPy, Y-TBAPy, and Fe-TBAPy (TBAPy: 1,3,6,8-tetrakis(p-benzoic acid)pyrene), were characterized and evaluated for their ability to remediate glyphosate (GP) from water. Among these materials, Sc-TBAPy demonstrates superior performance in both the adsorption and degradation of GP. Upon light irradiation for 5 min, Sc-TBAPy completely degrades 100% of GP in a 1.5 mM aqueous solution. Femtosecond transient absorption spectroscopy reveals that Sc-TBAPy exhibits enhanced charge transfer character compared to the other MOFs, as well as suppressed formation of emissive excimers that could impede photocatalysis. This finding was further supported by hydrogen evolution half-reaction (HER) experiments, which demonstrated Sc-TBAPy's superior catalytic activity for water splitting. In addition to its faster adsorption and more efficient photodegradation of GP, Sc-TBAPy also followed a selective pathway towards the oxidation of GP, avoiding the formation of toxic aminomethylphosphonic acid observed with the other M3+-TBAPy MOFs. To investigate the selectivity observed with Sc-TBAPy, electron spin resonance, depleted oxygen conditions, and solvent exchange with D2O were employed to elucidate the role of different reactive oxygen species on GP photodegradation. The findings indicate that singlet oxygen (1O2) plays a critical role in the selective photodegradation pathway achieved by Sc-TBAPy.

Systemic Analysis of Glyphosate Impact on Environment and Human Health

With a growing global population, agricultural scientists are focusing on crop production management and the creation of new strategies for a higher agricultural output. However, the growth of undesirable plants besides the primary crop poses a significant challenge in agriculture, necessitating the massive application of herbicides to eradicate this problem. Several synthetic herbicides are widely utilized, with glyphosate emerging as a potential molecule for solving this emerging issue; however, it has several environmental and health consequences. Several weed species have evolved resistance to this herbicide, therefore lowering agricultural yield. The persistence of glyphosate residue in the environment, such as in water and soil systems, is due to the misuse of glyphosate in agricultural regions, which causes its percolation into groundwater via the vertical soil profile. As a result, it endangers many nontarget organisms existing in the natural environment, which comprises both soil and water. The current Review aims to provide a systemic analysis of glyphosate, its various effects on the environment, its subsequent impact on human health and animals, which will lead us toward a better understanding of the issues about herbicide usage and aid in managing it wisely, as in the near the future glyphosate market is aiming for a positive forecast until 2035.

Detection of glyphosate residues in agricultural products using liquid-crystal-based sensor exploiting competitive binding of glyphosate and Cu2+ at the aqueous/LC interface and capillary tube test strip

Glyphosate is a widely used herbicide that poses both health and environmental risks. In this study, we propose a liquid crystal (LC)-based assay for glyphosate detection that exploits the unique properties of LC materials. The nematic LC 4-cyano-4'-pentylbiphenyl (5CB) was employed as the sensing material and a self-assembled monolayer of octadecyltrichlorosilane (OTS) was used to modify glass substrates. The assay involved strong competition for coordination with Cu2+ for glyphosate, resulting in changes in the LC texture. By monitoring and analyzing the optical images of the LC film using polarizing microscopy, we detected and quantified the glyphosate concentrations. The proposed assay demonstrated high sensitivity and selectivity toward glyphosate in the detection range of 1-300 nM with a limit of detection of 0.26 nM. Moreover, the assay successfully applied to analyze glyphosate in spiked samples, including tap water, soil, and cabbage, and satisfactory recovery rates were achieved. Based on this detection principle, capillary tube test strips were developed for on-site applications. The detection thresholds of the test strips were controlled by varying the Cu2+ concentration. The developed LC-based assay is a rapid and reliable glyphosate detection method with potential applications in environmental monitoring and food safety.

Developmental effects of zebrafish (Danio rerio) embryos after exposure to glyphosate and lead mixtures

Natural aquatic environments have a heterogeneous composition; therefore, simultaneous exposure to multiple contaminants is relevant and more realistic when assessing exposure and toxicity. This study examines the combinatorial effects of two compounds found ubiquitously in drinking water across the United States: glyphosate and lead acetate. Zebrafish (Danio rerio) embryos were used as a model for investigating developmental delays following controlled exposures. Six different environmentally relevant exposure concentrations of glyphosate, ranging from 0.001 to 10 ppm, and lead acetate, ranging from 0.5 to 4 ppm, were applied first as single exposures and then as co-exposures. The sublethal endpoints of hatching and coagulation were quantified to determine potencies. Results indicate that higher concentrations of the individual chemicals correlate with later hatching with correlation coefficients of 0.71 and 0.40 for glyphosate and lead acetate respectively, while the co-exposure at lower concentrations induced earlier hatching with a correlation coefficient 0.74. In addition, increased levels of coagulation and glutathione reductase activity were observed following co-exposure, as compared to the individual exposures, suggesting potential toxicological interactions. These results support the need for further work assessing the combined potencies of aquatic contaminants rather than individual exposures.

Exposure to sublethal concentrations of imidacloprid, pyraclostrobin, and glyphosate harm the behavior and fat body cells of the stingless bee Scaptotrigona postica

Pesticide use in agriculture threatens non-target insects such as bees. Considering the ecological and economic relevance of native bees, such as Scaptotrigona postica, and the insufficient studies on the effects of pesticides on their behavior and physiology, improving the current knowledge on this issue is essential. Therefore, this study investigated the sublethal effects of imidacloprid, pyraclostrobin, and glyphosate on the behavior and fat body cells of S. postica. Pesticide ingestion decreased the walking distance and mean velocity of bees compared to the control and solvent control groups. The oenocytes of the control groups were spherical, with central nuclei containing decondensed chromatin, and the trophocytes presented irregular morphology, with cells varying in shape and the cytoplasm filled with vacuoles and granules. However, bees exposed to pesticides showed extensive cytoarchitectural disruption in the fat body, such as vacuolization and shape changes in oenocytes and altered nuclei morphology in trophocytes. Moreover, pesticide exposure increased the number of atypical oenocytes and altered trophocytes, except for the PYR group, which showed a lower number of atypical oenocytes. Caspase-positive labeling significantly increased in all exposed bee groups. Alternatively, TLR4 labeling was significantly decreased in the exposed groups compared to the control groups. There was a significant increase in HSP90 immunolabeling in all exposed groups compared to the control. These findings reinforce the importance of research on the sublethal effects of low pesticide concentrations on key neotropical pollinators and prove that these toxic substances can impair their detoxification and immune defense.

Measuring herbicide (73.3 % glyphosate) exposure response in Halophila ovalis (previously johnsonii) and Halodule wrightii seagrass

We evaluated the effects of Roundup QuikPRO™ (73.3 % glyphosate) using real-world herbicide application treatments: (1) overspray (low-dose), (2) powder spill (high-dose), and (3) controls (no-dose). Seagrass and water quality were monitored to observe responses to acute herbicide application. Seagrass shoot densities significantly declined over time in high-dose treatments, whereas seagrass shoot densities in low-dose treatments were comparable to controls. In high-dose treatments, seagrass mortality increased over time, 100 % Halophila ovalis and 81 % Halodule wrightii mortality from day zero to 53. Collectively, glyphosate concentrations were negatively correlated with seagrass shoot densities, and positively correlated with water column nutrients (TN and TP). Based on these results we do not attribute local seagrass declines to low-dose glyphosate exposure, i.e., herbicide overspray events. However, we advise caution against improper herbicide handling, since glyphosate remained detectable in relatively high concentrations (<88 mg/L) after 53 days, resulting in seagrass mortality and increased water column nutrients.

Kinetics of glyphosate and aminomethylphosphonic acid sorption onto montmorillonite clays in soil and their translocation to genetically modified corn

The co-occurrence of glyphosate (GLP) and aminomethylphosphonic acid (AMPA) in contaminated water, soil, sediment and plants is a cause for concern due to potential threats to the ecosystem and human health. A major route of exposure is through contact with contaminated soil and consumption of crops containing GLP and AMPA residues. However, clay-based sorption strategies for mixtures of GLP and AMPA in soil, plants and garden produce have been very limited. In this study, in vitro soil and in vivo genetically modified corn models were used to establish the proof of concept that the inclusion of clay sorbents in contaminated soils will reduce the bioavailability of GLP and AMPA in soils and their adverse effects on plant growth. Effects of chemical concentration (1-10 mg/kg), sorbent dose (0.5%-3% in soil and 0.5%-1% in plants) and duration (up to 28 days) on sorption kinetics were studied. The time course results showed a continuous GLP degradation to AMPA. The inclusion of calcium montmorillonite (CM) and acid processed montmorillonite (APM) clays at all doses significantly and consistently reduced the bioavailability of both chemicals from soils to plant roots and leaves in a dose- and time-dependent manner without detectable dissociation. Plants treated with 0.5% and 1% APM inclusion showed the highest growth rate (p ≤ 0.05) and lowest chemical bioavailability with up to 76% reduction in roots and 57% reduction in leaves. Results indicated that montmorillonite clays could be added as soil supplements to reduce hazardous mixtures of GLP and AMPA in soils and plants.

Unlocking the potential of glyphosate-resistant bacterial strains in biodegradation and maize growth

Glyphosate [N-(phosphonomethyl)-glycine] is a non-selective herbicide with a broad spectrum activity that is commonly used to control perennial vegetation in agricultural fields. The widespread utilization of glyphosate in agriculture leads to soil, water, and food crop contamination, resulting in human and environmental health consequences. Therefore, it is imperative to devise techniques for enhancing the degradation of glyphosate in soil. Rhizobacteria play a crucial role in degrading organic contaminants. Limited work has been done on exploring the capabilities of indigenously existing glyphosate-degrading rhizobacteria in Pakistani soils. This research attempts to discover whether native bacteria have the glyphosate-degrading ability for a sustainable solution to glyphosate contamination. Therefore, this study explored the potential of 11 native strains isolated from the soil with repeated glyphosate application history and showed resistance against glyphosate at higher concentrations (200 mg kg-1). Five out of eleven strains outperformed in glyphosate degradation and plant growth promotion. High-pressure liquid chromatography showed that, on average, these five strains degraded 98% glyphosate. In addition, these strains promote maize seed germination index and shoot and root fresh biomass up to 73 and 91%, respectively. Furthermore, inoculation gave an average increase of acid phosphatase (57.97%), alkaline phosphatase (1.76-fold), and dehydrogenase activity (1.75-fold) in glyphosate-contaminated soil. The findings indicated the importance of using indigenous rhizobacteria to degrade glyphosate. Therefore, by maintaining soil health, indigenous soil biodiversity can work effectively for the bioremediation of contaminated soils and sustainable crop production in a world facing food security.

Glyphosate decreases survival, increases fecundity, and alters the microbiome of the natural predator Harmonia axyridis (ladybird beetle)

Glyphosate is a widely-used herbicide that shows toxicity to non-target organisms. The predatory natural enemy Harmonia axyridis may ingest glyphosate present in pollen and aphid prey. The present study characterized the responses of adult H. axyridis to environmentally relevant concentrations of glyphosate (5, 10, and 20 mg/L) for one or five days. There were no obvious effects on adult H. axyridis survival rates or fecundity in response to 5 or 10 mg/L glyphosate. However, exposure to 20 mg/L glyphosate significantly reduced the survival rate and increased fecundity. Analysis of the adult H. axyridis microbiota with 16S rRNA sequencing demonstrated changes in the relative and/or total abundance of specific taxa, including Serratia, Enterobacter, Staphylococcus, and Hafnia-Obesumbacterium. These changes in symbiotic bacterial abundance may have led to changes in survival rates or fecundity of this beetle. This is the first report of herbicide-induced stimulation of fecundity in a non-target predatory natural enemy, reflecting potentially unexpected risks of glyphosate exposure in adult H. axyridis. Although glyphosate resistant crops have been widely planted, the results of this study indicate a need to strengthen glyphosate management to prevent over-use, which could cause glyphosate toxicity and threaten environmental and human health.

Determination of glyphosate and aminomethylphosphonic acid residues in Finnish soils by ultra-high performance liquid chromatography-tandem mass spectrometry

Glyphosate [N-(phosphonomethyl) glycine] (GLY) adsorbs strongly in Finnish soils. A new method for GLY and its main degradation product, aminomethylphosphonic acid (AMPA) residues in clay soils (Protovertic Luvisol) was developed and validated. A new method was necessary because the previous one required laborious cleaning pre-treatments, and its recovery was quite poor (<40%-70%). In the new method, the earlier method's extraction solvent, 0.1 M potassium hydroxide (KOH), was replaced by more effective 0.6 M KOH. The old post-column high-performance liquid chromatography and fluorescence (HPLC-FLD) method was replaced by the ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method. Compounds were identified as their fluorenyl methyl chloroformate (FMOC) derivatives by a multiple reaction monitoring (MRM) technique and quantified by an internal standard method utilising multipoint matrix-matched calibration. Glufosinate-ammonium (GLUF) was used to monitor the effectiveness of extraction with good recovery (80-119%). All calibration curves were found to be linear (R2 ≥ 0.98) in the studied calibration range (0.01-3.31 mg kg-1 in fresh soil). The repeatability and reproducibility were 25% and 28% for GLY, and 20% and 24% for AMPA in real research soil samples. The method was effective throughout the calibration range in all the studied Finnish agricultural soils.•An improved method was created to analyse glyphosate (GLY) and AMPA in Finnish clay soil.•The challenge caused by strong GLY adsorption on soil was solved by using multipoint matrix-matched calibration curve samples which were prepared identically with the research samples.•The method performed well in all tested clay, loam and sandy loam soils.

Glyphosate in the environment: interactions and fate in complex soil and water settings, and (phyto) remediation strategies

Glyphosate (Gly) and its formulations are broad-spectrum herbicides globally used for pre- and post-emergent weed control. Glyphosate has been applied to terrestrial and aquatic ecosystems. Critics have claimed that Gly-treated plants have altered mineral nutrition and increased susceptibility to plant pathogens because of Gly ability to chelate divalent metal cations. Still, the complete resistance of Gly indicates that chelation of metal cations does not play a role in herbicidal efficacy or have a substantial impact on mineral nutrition. Due to its extensive and inadequate use, this herbicide has been frequently detected in soil (2 mg kg-1, European Union) and in stream water (328 µg L-1, USA), mostly in surface (7.6 µg L-1, USA) and groundwater (2.5 µg L-1, Denmark). International Agency for Research on Cancer (IARC) already classified Gly as a category 2 A carcinogen in 2016. Therefore, it is necessary to find the best degradation techniques to remediate soil and aquatic environments polluted with Gly. This review elucidates the effects of Gly on humans, soil microbiota, plants, algae, and water. This review develops deeper insight toward the advances in Gly biodegradation using microbial communities. This review provides a thorough understanding of Gly interaction with mineral elements and its limitations by interfering with the plants biochemical and morphological attributes.

GLYPHOSATE IMPACT on human health and the environment: Sustainable alternatives to replace it in Mexico

Glyphosate is a broad-spectrum, non-selective herbicide used to control weeds and protect agricultural crops, and it is classified as potentially carcinogenic by the International Agency for Research on Cancer. In Mexico, the use of pesticides is a common practice, including glyphosate. However, on December 31st, 2020, the Mexican government decreed the prohibition of this herbicide as of January 2024. In this review, we investigate the association between glyphosate and cancer risk and found that most of the studies focused using animals showing negative effects such as genotoxicity, cytotoxicity and neurotoxicity, some studies used cancer cell lines showing proliferative effects due to glyphosate exposure. To our knowledge, in Mexico, there are no scientific reports on the association of glyphosate with any type of cancer. In addition, we reviewed the toxicological effects of the herbicide glyphosate, and the specific case of the current situation of the use and environmental damage of this herbicide in Mexico. We found that few studies have been published on glyphosate, and that the largest number of publications are from the International Agency for Research on Cancer classification to date. Additionally, we provide data on glyphosate stimulation at low doses as a biostimulant in crops and analytical monitoring techniques for the detection of glyphosates in different matrices. Finally, we have tried to summarize the actions of the Mexican government to seek sustainable alternatives and replace the use of glyphosate, to obtain food free of this herbicide and take care of the health of the population and the environment.

Glyphosate and environmental toxicity with "One Health" approach, a review

The herbicide Glyphosate (GLY), or N-(phosphonomethyl) glycine was synthesized in 1950 and applied to control weeds in agricultural production. For a long time, it was believed that it was an inert compound, but many studies have instead demonstrated over the years the dangers of GLY to the ecosystem and human health. Among the best-known effects, it is known that GLY interferes with the metabolic pathways of plants and the main groups of microorganisms, negatively influencing their growth. GLY interferes with the metabolic pathways of plants and major groups of microorganisms negatively affecting their growth. The extensive GLY application on fields results in a "slow death" of plants through the minor resistance to root pathogens and in increasing pollution of freshwaters and soils. Unfortunately, however, unlike the old beliefs, GLY can reach non-target destinations, in this regard, ecological studies and environmental epidemiology are of significant interest. In this review, we focus on the effects of acute and chronic exposure to GLY on the health of plants, animals, and humans from a One Health perspective. GLY has been linked to neurological and endocrine issues in both humans and animals, and behavioral modification on specific bioindicators, but the knowledge about the ratio cause-and-effect still needs to be better understood and elucidated. Environmental GLY residues analysis and policy acts will both require new criteria to protect environmental and human health.

Seasonal variations in the levels of glyphosate in soil, water and crops from three farm settlements in Oyo state, Nigeria

This study investigated the concentration of glyphosate in water (groundwater and surface), soil (top and sub) on cassava and maize farms within 3 farm settlements (Akufo, Ilora and Otiri Ipapo) from Ido, Oyo and Iseyin Local Government Areas of Oyo state, Nigeria. Samples of Top and sub soil were taken from the farms while water was collected from wells (groundwater) and streams (surface water) around each farm settlement using standard methods. Crops (cassava and Maize) samples were collected from each of the selected farm after harvest. The samples were collected over a six-month period to reflect seasonal variation. The glyphosate levels were determined using HPLC-FLD after liquid-liquid extraction technique for water and soxhlet extraction for soil crops The pH, electrical conductivity (EC), total dissolved solids (TDS) values for groundwater were within the WHO limits while values recorded for surface water were above the WHO limits. The phosphate and nitrate values were high in surface water compared to groundwater. High concentration of the exchangeable cations were recorded at the top soil for all the farms with values ranging from 4.0 ± 0.1 to 8.2 ± 0.0 for Ca2+, 2.9 ± 0.0 to 5.1 ± 0.1 for Mg2+, 0.3 ± 0.2 to 0.55 ± 0.0 for Na+, and 0.32 ± 0.0 to 8.2 ± 0.0 for K+. the residual concentration of glyphosate taken from wells and taps (groundwater) were within the maximum concentration of glyphosate in drinking water (0.7 mgL-1). Glyphosate concentrations observed were higher in soil samples from all farm settlements during wet season compared to dry, higher concentrations were also observed in surface water during wet season (August) compared to dry, with Akufo farm settlement having the highest concentrations of 29.40 ± 0.83 mgL-1. The glyphosate residues were also higher in cassava (0.3 ± 0.0 mgKg-1) compared to maize (0.07 ± 0.08 mgKg-1) across each farm settlement. Generally, the higher concentrations observed during wet season in both soil and water samples were as a result of active farm activities during wet season and run off respectively. If herbicide usage is not properly monitored within these settlements, it can pose a threat to aquatic animals and humans around the settlements, thus a sustainable and conservative farming is advised.

Urinary Glyphosate Concentrations among Pregnant Participants in a Randomized, Crossover Trial of Organic and Conventional Diets

BACKGROUND

Consumption of an organic diet reduces exposure to a range of agricultural pesticides. Only three studies have examined the effect of an organic diet intervention on exposure to the herbicide glyphosate, the most heavily used agricultural chemical in the world. Despite its widespread use, the primary sources of glyphosate exposure in humans are poorly understood.

OBJECTIVE

Our objective was to examine the effect of an organic diet intervention on urinary glyphosate concentrations among pregnant individuals.

METHODS

We conducted a 2-wk randomized crossover trial in which 39 pregnant participants living near (≤ 0.5 km ) and far (> 0.5 km ) from agricultural fields received a 1-wk supply of conventional groceries and 1 wk of organic groceries, randomized to order. We collected daily first morning void urine samples and analyzed composite samples from each week for glyphosate. We examined differences in urinary glyphosate concentrations between the conventional week and the organic week among all participants and stratified by residential proximity to an agricultural field.

RESULTS

Median specific gravity-adjusted glyphosate concentrations were 0.19 μ g / L and 0.16 μ g / L during the conventional and organic weeks, respectively. We observed modest decreases in urinary glyphosate concentrations from the conventional to organic week among far-field participants, but no difference among near-field participants. In secondary analyses excluding participants who did not meet a priori criteria of compliance with the intervention, we observed significant decreases in urinary glyphosate concentrations, particularly among far-field participants (p < 0.01 - 0.02 , depending on exclusion criteria).

DISCUSSION

This trial is the first to examine the effect of an organic diet intervention on glyphosate among people living near and far from agricultural fields. Our results suggest that diet is an important contributor to glyphosate exposure in people living > 0.5 km from agricultural fields; for people living near crops, agriculture may be a dominant exposure source during the pesticide spray season. https://doi.org/10.1289/EHP12155.

Impact of Human Activities on Disease-Spreading Mosquitoes in Urban Areas

Urbanization is one of the leading global trends of the twenty-first century that has a significant impact on health. Among health challenges caused by urbanization, the relationship of urbanization between emergence and the spread of mosquito-borne infectious diseases (MBIDs) is a great public health concern. Urbanization processes encompass social, economic, and environmental changes that directly impact the biology of mosquito species. In particular, urbanized areas experience higher temperatures and pollution levels than outlying areas but also favor the development of infrastructures and objects that are favorable to mosquito development. All these modifications may influence mosquito life history traits and their ability to transmit diseases. This review aimed to summarize the impact of urbanization on mosquito spreading in urban areas and the risk associated with the emergence of MBIDs. Moreover, mosquitoes are considered as holobionts, as evidenced by numerous studies highlighting the role of mosquito-microbiota interactions in mosquito biology. Taking into account this new paradigm, this review also represents an initial synthesis on how human-driven transformations impact microbial communities in larval habitats and further interfere with mosquito behavior and life cycle in urban areas.

An ultrasensitive LC-MS/MS method for the determination of glyphosate, AMPA and glufosinate in water - analysis of surface and groundwater from a hydrographic basin in the Midwestern region of Brazil

The intensive use of glyphosate around the world in the last few decades demands constant monitoring of this compound and its metabolite in aquatic compartments. This work aimed to develop a sensitive method for the analysis of glyphosate, AMPA and glufosinate in water by liquid chromatography/tandem mass spectrometry (LC-MS/MS). The method involves analyte concentration by lyophilization (20×) and direct injection on the LC-MS/MS, and was satisfactorily validated at a LOQ of 0.0025 μg L^-1. A total of 142 samples of surface and groundwater collected during the 2021/2022 dry and rainy seasons in the Rio Preto Hydrographic Basin were analyzed. All the 52 groundwater samples were positive for glyphosate (up to 1.5868 μg L^-1, dry season) and AMPA (up to 0.2751 μg L^-1, dry season). A total of 27 of the 90 surface water samples were positive for glyphosate (up to 0.0236 μg L^-1), and 31 samples for AMPA (up to 0.0086 μg L^-1), of which over 70 % collected during the dry season. Glufosinate was detected in only five samples, four in groundwater (up to 0.0256 μg L^-1). The levels found in the samples are much lower than the maximum levels established by the Brazilian legislation for glyphosate and/or AMPA and lower than the most critical toxicological endpoints for aquatic organisms. However, constant monitoring is necessary, demanding sensitive methods to allow the detection of the very low levels of these pesticides in water.

Discrepancies in rhizobacterial assembly caused by glyphosate application and herbicide-tolerant soybean Co-expressing GAT and EPSPS

There are concerns that the innovation of genetically modified herbicide-tolerant (GMHT) plants, as well as the application of herbicide to such GMHT plants, could have an impact on ecological interactions and unintentionally harm non-targeted organisms. Consequently, we intend to use full-length 16 S rDNA amplicon sequencing to examine changes in the bacterial community in the rhizosphere of GMHT soybean (Z106) harboring 5-enolpyruvylshikimate-3-phosphate synthase and Glyphosate N-acetyltransferase genes and GMHT soybean treated with glyphosate (Z106G). Glyphosate application significantly impacted bacterial alpha diversity (species richness, and Shannon diversity). Permutational multivariate analysis of variance of beta diversity demonstrated that soil compartments and growth stages had a substantial impact on soybean rhizobacterial communities (soil compartments, growth stages, P = 0.001). Community composition revealed that Z106G soils were abundant in Taibaiella and Arthrobacter pascens at maturity, while Chryseobacterium joostei and Stenotrophomonas maltophilia predominated in Z106 soils during flowering. Nitrogen-fixing and phosphate-solubilizing microbes were found in higher proportions in the rhizosphere than in bulk soil, with Sinorhizobium being more abundant in Z106 and Bacillus and Stenotrophomonas being more prevalent in Z106G rhizosphere soils. Collectively, our findings suggest glyphosate application and glyphosate-tolerant soybean as potential regulators of soybean rhizobacterial composition.

Xylopia aethiopica suppresses markers of oxidative stress, inflammation, and cell death in the brain of Wistar rats exposed to glyphosate

The herbicide "Roundup" is used extensively in agriculture to control weeds. However, by translocation, it can be deposited in plants, their proceeds, and the soil, thus provoking organ toxicities in exposed individuals. Neurotoxicity among others is one of the side effects of roundup which has led to an increasing global concern about the contamination of food by herbicides. Xylopia aethiopica is known to have medicinal properties due to its antioxidative and anti-inflammatory properties, and it is hypothesized to neutralize roundup-induced neurotoxicity. Thirty-six (36) Wistar rats were used for this study. The animals were shared equally into six groups with six rats each. Glyphosate administration to three of the six groups was done orally and for 1 week. Either Xylopia aethiopica or vitamin C was co-administered to two of the three groups and also administered to two other groups and the final group served as the control. Our studies demonstrated that glyphosate administration led to a significant decrease in antioxidants such as catalase, superoxide dismutase, glutathione, and glutathione peroxidase. We also observed a significant increase in inflammatory markers such as tumor necrosis factor-α, interleukin 6, C-reactive protein, and immunohistochemical expression of caspase-3, cox-2, and p53 proteins (p < 0.05). However, Xylopia aethiopica co-administration with glyphosate was able to ameliorate the aforementioned changes when compared to the control (p < 0.05). Degenerative changes were also observed in the cerebellum, hippocampus, and cerebral cortex upon glyphosate administration. These changes were not observed in the groups treated with Xylopia aethiopica and vitamin C. Taken together, Xylopia aethiopica could possess anti-oxidative and anti-inflammatory properties that could be used in combating glyphosate neurotoxicity.

Agronomic performance and quality of baby corn in response to the inoculation of seeds with Azospirillum brasilense and nitrogen fertilization in the summer harvest

The association with Azospirillum brasilense promotes better growth and development in corn plants due to biological N fixation, the capacity to help in the synthesis of phytohormones and to improve the use of nutrients by crop plants. However, there aren't specific recommendations for the use of inoculation in baby corn crop. Thus, this study aimed to evaluate the effects of seed inoculation with A. brasilense, associated with nitrogen fertilization management, on the agronomic performance and chemical quality of baby corn grown in three summer growing seasons (2014/2015; 2015/2016 and 2016/2017). The evaluated treatments consisted of combination of five levels of seed inoculation (0.0, 50, 100, 150 and 200 mL 60,000 seeds^-1) based on Azospirillum brasilense, two levels of nitrogen fertilization at sowing time (0.0 and 30.0 kg of N ha^-1) and two levels of nitrogen in topdressing (0.0 and 110.0 kg of N ha^-1), applied at the V4 stage of the popcorn hybrid IAC 125. The characteristics evaluated were: leaf area index (LAI), leaf nitrogen content (LNC), total husked spikelets yield (HSY) and commercial spikelets yield (CSY), and the chemical characteristics of the commercial spikelets: crude protein content (CPC), starch content (STC) and total sugar content (TSC). The inoculation, when combined with nitrogen fertilization, provided positive responses for LAI and provided an average increment of 6 kg ha^-1 to CSY for every 10 mL 60,000 seeds^-1 of inoculant added to the seeds. The LNC, CPC, STC and TSC weren't affected by seed inoculation. Nitrogen fertilization provided increments for all characteristics evaluated, except for TSC, which was negatively affected by nitrogen topdressing. The baby corn crop responded positively to seed inoculation with Azospirillum brasilense, combined with Nitrogen fertilization.

Awaking the dormant virome in the rhizosphere

The rhizosphere is a vital soil compartment providing key plant-beneficial functions. However, little is known about the mechanisms driving viral diversity in the rhizosphere. Viruses can establish lytic or lysogenic interactions with their bacterial hosts. In the latter, they assume a dormant state integrated in the host genome and can be awakened by different perturbations that impact host cell physiology, triggering a viral bloom, which is potentially a fundamental mechanism driving soil viral diversity, as 22%-68% of soil bacteria are predicted to harbour dormant viruses. Here we assessed the viral bloom response in rhizospheric viromes by exposing them to three contrasting soil perturbation agents: earthworms, herbicide and antibiotic pollutant. The viromes were next screened for rhizosphere-relevant genes and also used as inoculant on microcosms incubations to test their impacts on pristine microbiomes. Our results show that while post-perturbation viromes diverged from control conditions, viral communities exposed to both herbicide and antibiotic pollutant were more similar to each other than those influenced by earthworms. The latter also favoured an increase in viral populations harbouring genes involved in plant-beneficial functions. Post-perturbation viromes inoculated on soil microcosms changed the diversity of pristine microbiomes, suggesting that viromes are important components of the soil ecological memory driving eco-evolutionary processes that determine future microbiome trajectories according to past events. Our findings demonstrate that viromes are active players in the rhizosphere and need to be considered in efforts to understand and control the microbial processes towards sustainable crop production.

Biopesticides as a promising alternative to synthetic pesticides: A case for microbial pesticides, phytopesticides, and nanobiopesticides

Over the years, synthetic pesticides like herbicides, algicides, miticides, bactericides, fumigants, termiticides, repellents, insecticides, molluscicides, nematicides, and pheromones have been used to improve crop yield. When pesticides are used, the over-application and excess discharge into water bodies during rainfall often lead to death of fish and other aquatic life. Even when the fishes still live, their consumption by humans may lead to the biomagnification of chemicals in the body system and can cause deadly diseases, such as cancer, kidney diseases, diabetes, liver dysfunction, eczema, neurological destruction, cardiovascular diseases, and so on. Equally, synthetic pesticides harm the soil texture, soil microbes, animals, and plants. The dangers associated with the use of synthetic pesticides have necessitated the need for alternative use of organic pesticides (biopesticides), which are cheaper, environment friendly, and sustainable. Biopesticides can be sourced from microbes (e.g., metabolites), plants (e.g., from their exudates, essential oil, and extracts from bark, root, and leaves), and nanoparticles of biological origin (e.g., silver and gold nanoparticles). Unlike synthetic pesticides, microbial pesticides are specific in action, can be easily sourced without the need for expensive chemicals, and are environmentally sustainable without residual effects. Phytopesticides have myriad of phytochemical compounds that make them exhibit various mechanisms of action, likewise, they are not associated with the release of greenhouse gases and are of lesser risks to human health compared to the available synthetic pesticides. Nanobiopesticides have higher pesticidal activity, targeted or controlled release with top-notch biocompatibility and biodegradability. In this review, we examined the different types of pesticides, the merits, and demerits of synthetic pesticides and biopesticides, but more importantly, we x-rayed appropriate and sustainable approaches to improve the acceptability and commercial usage of microbial pesticides, phytopesticides, and nanobiopesticides for plant nutrition, crop protection/yield, animal/human health promotion, and their possible incorporation into the integrated pest management system.

Ecotoxicological relevance of glyphosate and flazasulfuron to soil habitat and retention functions - Single vs combined exposures

Glyphosate (GLY) and flazasulfuron (FLA) are two non-selective herbicides commonly applied together. However, research focused on their single and combined ecotoxicological impacts towards non-target organisms is still inconclusive. Therefore, this study aimed to test their single effects on soil's habitat and retention functions, and to unravel their combined impacts to earthworms and terrestrial plants. For this, ecotoxicological assays were performed with plants (Medicago sativa), oligochaetes (Eisenia fetida) and collembola (Folsomia candida). Soil elutriates were also prepared and tested in macrophytes (Lemna minor) and microalgae (Raphidocelis subcapitata). FLA (82-413 µg kg^-1) reduced earthworms' and collembola's reproduction and severely impaired M. sativa growth, being much more toxic than GLY (up to 30 mg kg^-1). In fact, the latter only affected plant growth (≥ 9 mg kg^-1) and earthworms (≥ 13 mg kg^-1), especially at high concentrations, with no effects on collembola. Moreover, only elutriates from FLA-contaminated soils significantly impacted L. minor and R. sucapitata. The experiments revealed that the co-exposure to GLY and FLA enhanced the toxic effects of contaminated soils not only on plants but also on earthworms'. However, such increase in toxicity was dependent on GLY residual concentrations in soils. Overall, this work underpins that herbicides risk assessment should consider herbicides co-exposures, since the evaluation of single exposures is not representative of current phytosanitary practices and of the potential effects under field conditions, where residues of different compounds may persist in soils.

Exposure of children to glyphosate in Morocco: Urinary levels and predictors of exposure

Glyphosate is one of the most frequently used organophosphorus plant protection products worldwide, and has recently been classified as probably carcinogenic to humans by the International Agency for Research and Cancer (IARC). We aimed to evaluate the urinary levels of glyphosate and its metabolite aminomethylphosphonic acid (AMPA) in Moroccan children, to identify the main predictors and to perform a risk assessment. Data was collected during a cross sectional study of 48 children from an intensive agricultural area. Measurements included a questionnaire on life-style, socio-demographic and herbicide exposures. Urinary glyphosate and AMPA were extracted using solid phase extraction (SPE) and analyzed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Overall, glyphosate and AMPA were detected in 73% and 75% of urine samples, respectively. The mean concentrations were 0.97 μg L^-1 (2.06 μg/g_creatinine) for glyphosate and 0.79 μg L^-1 (1.52 μg/g_creatinine) for AMPA. Children younger than 5 years had a higher AMPA and glyphosate urine concentration (mean = 2.24 μg L^-1; estimation coefficient (EC) = 1.39; 95% CI: 0.54-2.24) (mean = 4.05 μg L^-1; EC = 2.92; 95% CI: 1.68-4.15), respectively, than children aged 6-12. Children living near the pesticide spraying fields (<50 m) had 14.91 μg L^-1 and 2.35 μg L^-1 more glyphosate and AMPA, respectively, than children living in urban counties (95% CI: 8.14-20.91 for glyphosate and 95% CI: 0.55-4.14 for AMPA). AMPA concentration varied significantly with the source of drinking water, AMPA was higher among children that used water from open water sources (mean = 1.49 μg L^-1; EC = 2.98; 95% CI/0.67-5.78) compared to those using water from closed water sources. There were also non-significant associations found, such as total household net income, current parental job description, and dietary intake. With the regard to the health risk assessment, estimated daily intake (EDIs), hazard quotient (HQs), and a hazard index (HI) were calculated. The GMs of EDI were 4.38 and 2.26 μg/kg of body weight BW/day for glyphosate and AMPA, respectively. The HQs were calculated considering 0.5 mg/kg BW/day as an acceptable daily intake (ADI), which EFSA has established as a health-based reference value for both analytes. The value obtained were lower than 1, and therefore, low health risk due to glyphosate and AMPA was expected for the target population under the study. This study provides further evidence on factors associated with glyphosate exposure, especially in developing countries.

Adsorption and detoxification of glyphosate and aminomethylphosphonic acid by montmorillonite clays

The co-occurrence of mixtures of glyphosate (GLP) and aminomethylphosphonic acid (AMPA) in contaminated water, soil, sediment, and plants is a cause for concern due to potential threats to the ecosystem and human health. Major routes of exposure include contact with contaminated water and soil and through consumption of crops containing GLP and AMPA residues. Calcium montmorillonite (CM) and acid-processed montmorillonite (APM) clays were investigated for their ability to tightly sorb and detoxify GLP and AMPA mixtures. In vitro adsorption and desorption isotherms and thermodynamic analysis indicated saturable Langmuir binding of both chemicals with high capacities, affinities, enthalpies, and free energies of sorption and low desorption rates. In silico computational modeling indicated that both GLP and AMPA can be readily absorbed onto clay surfaces through electrostatic interactions and hydrogen bonding. The safety and efficacy of the clays were confirmed using well-established living organisms, including an aquatic cnidarian (Hydra vulgaris), a soil nematode (Caenorhabditis elegans), and a floating plant (Lemna minor). Low levels of clay inclusion (0.05% and 0.2%) in the culture medium resulted in increased growth and protection against chemical mixtures based on multiple endpoints. Results indicated that montmorillonite clays may be used to bind mixtures of GLP and AMPA in water, soil, and plants.

Reversibility of glyphosate sorption in pampean loess-derived soil profiles of central Argentina

There is a growing concern about glyphosate's behavior in the environment. Herbicide behavior in soils greatly depends on adsorption-desorption phenomena, which have shown great variability in soils, although the reversibility of this process has been less examined. The adsorption-desorption behavior of glyphosate was measured on representative soil profiles of the northeast region of Argentinean Pampas, a semi-arid crop cultivating region. Two soil profiles samples (P1 and P2, both Entic Haplustoll) were collected and segmented into depth increments of 0-10, 10-20, 20-40, 40-60, 60-80, and 80-100 cm. Batch adsorption/48 h-desorption isotherms were performed in a controlled setup. Soil samples had a high sand content (77-92%), and a low content of clay (<3%), but markedly differing in the available P content, especially in the upper layers of soil profiles (0-40 cm, P1 range 133-170 ppm; P2 range 7-43 ppm). Adsorption-desorption isotherms showed a similar range of variation, between 150 and 1400 L kg ^-1for K_Fads and 450-1400 L kg ^-1for K_Fdes, without appreciable evidence of hysteresis (0.95 ± 0.05). Sorption capacity parameters showed a distinct behavior with depth, P1 exhibiting a U-shape with minimum values at intermediate depths (20-60 cm), while P2 decreases sharply between 0 and 40 cm. General linear models considering the specific surface area (SSA) of each sample and the spatial correlation structure for soil profiles showed a main positive association of K_Fads and K_Fdes with the soil organic matter, together with a positive association with iron content (K_Fads), and a negative association of K_Fdes with available P content. These results indicate high adsorption extents and sorption reversibility of glyphosate to sandy loam soils of the region, which implies the potential for the herbicide to be available for leaching or degradation under a scenario of intensive use.

Glyphosate used as desiccant contaminates plant pollen and nectar of non-target plant species

Pesticide products containing glyphosate as a systemic active ingredient are some of the most extensively used herbicides worldwide. After spraying, residues have been found in nectar and pollen collected by bees foraging on treated plants. This dietary exposure to glyphosate could pose a hazard for flower-visiting animals including bees, and for the delivery of pollination services. Here, we evaluated whether glyphosate contaminates nectar and pollen of targeted crops and non-target wild plants. Oilseed rape was selected as focal crop species, and Rubus fruticosus growing in the hedgerows surrounding the crop was chosen as non-target plant species. Seven fields of oilseed rape, where a glyphosate-based product was applied, were chosen in east and southeast Ireland, and pollen and nectar were extracted from flowers sampled from the field at various intervals following glyphosate application. Pollen loads were taken from honeybees and bumblebees foraging on the crop at the same time. Glyphosate and aminomethylphosphonic acid (AMPA) residues were extracted using acidified methanol and their concentrations in the samples were determined by a validated liquid chromatography tandem mass spectrometry (LC-MS/MS) method. Glyphosate was detected in R. fruticosus nectar and pollen samples that were taken within a timeframe of two to seven days after the application on the crop as a desiccant. No glyphosate was detected when the application took place before or more than two months prior to our sampling in any of the evaluated matrices. The metabolite AMPA was not detected in any samples. To gain further insight into the potential extent of translocation within both plants and soil when a crop is desiccated using glyphosate before harvesting, and the potential impacts on bees, we recommend a longitudinal study of the presence and fate of glyphosate in non-target flowering plants growing nearby crop fields, over a period of several days after glyphosate application.

Legacy of agrochemicals in the circular food economy: Glyphosate-based herbicides introduced via manure fertilizer affect the yield and biochemistry of perennial crop plants during the following year

Conventional agricultural practices favoring the use of glyphosate-based herbicides (GBHs) increase the risk of GBH residues ending up in animal feed, feces, and, eventually, manure. The use of poultry manure as organic fertilizer in the circular food economy increases the unintentional introduction of GBH residues into horticultural and agricultural systems, with reportedly negative effects on the growth and reproduction of crop plants. To understand the potential lasting effects of exposure to GBH residues via organic manure fertilizers, we studied strawberry (Fragaria x vescana) plant performance, yield quantity, biochemistry, folivory, phytochemistry, and soil elemental composition the year after exposure to GBH. Although plants exposed to GBH residues via manure fertilizer were, on average, 23% smaller in the year of exposure, they were able to compensate for their growth during the following growing season. Interestingly, GBH residue exposure in the previous growing season led to a trend in altered plant size preferences of folivores during the following growing season. Furthermore, the plants that had been exposed to GBH residues in the previous growing season produced 20% heavier fruits with an altered composition of phenolic compounds compared to non-exposed plants. Our results indicate that GBHs introduced via manure fertilizer following circular economy practices in one year can have effects on perennial crop plants in the following year, although GBH residues in soil have largely vanished.

Conservation implications of herbicides on seagrasses: sublethal glyphosate exposure decreases fitness in the endangered Zostera capensis

Worldwide seagrass populations are in decline, calling for urgent measures in their conservation. Glyphosate is the most widely used herbicide globally, leading to increasing concern about its ecological impact, yet little is known about the prevalence or impact of glyphosate on seagrasses. In this study, we investigated the effect of sublethal glyphosate exposure on the endangered seagrass, Zostera capensis, to identify effects on growth, photosynthetic pigments and leaf morphology as measures of seagrass fitness. Seagrasses were exposed to a single dose of a commercial glyphosate formulation-ranging between 250 to 2,200 µg/L. After three weeks, the median leaf area decreased by up to 27%, with reductions of up to 31% in above ground biomass (p < 0.05). Photosynthetic pigment concentration showed no significant difference between groups. The observed effects on biomass and leaf area were seen at glyphosate levels below the regulatory limits set for surface water by several countries and may negatively affect the long-term resilience of this ecosystem engineer to additional stressors, such as those associated with climate change and anthropogenic pollution. As such, glyphosates and other herbicides that are washed into estuarine and marine ecosystems, pose a significant threat to the persistence of seagrasses and are important factors to consider in seagrass conservation, management and restoration efforts.

Glyphosate Sensor Based on Nanostructured Water-Gated CuO Field-Effect Transistor

This research presents a comparative analysis of water-gated thin film transistors based on a copper oxide (CuO) semiconductor in the form of a smooth film and a nanostructured surface. A smooth CuO film was deposited through reactive magnetron sputtering followed by annealing in atmosphere at a temperature of 280 ∘C. Copper oxide nanostructures were obtained by hydrothermal synthesis on a preliminary magnetron sputtered 2 nm thick CuO precursor followed by annealing at 280 ∘C. An X-ray diffraction (XRD) analysis of the samples revealed the presence of a tenorite (CuO) phase with a predominant orientation of (002). Scanning electron microscopy (SEM) and atomic force microscopy (AFM) studies of the samples revealed a highly developed surface with crystallites having a monoclinic syngony and dimensions of 15-20 nm in thickness, 150 nm in length, and 100 nm in height relative to a 2.5 nm height for the CuO crystallites of the smooth film. Electric measurements of the studied devices revealed typical current-voltage characteristics of semiconductors with predominant hole conductivity. The maximum ON/OFF ratio at a rain-source voltage of 0.4 volts and -1.2 volts on the gate for a smooth film was 102, and for a nanostructured transistor, it was 103. However, a much stronger saturation of the channel was observed for the nanostructured channel than for the smooth film. A test solution containing glyphosate dissolved in deionized water in three different concentrations of 5, 10, and 15 μmol/L was used during the experiments. The principle of operation was based on the preliminary saturation of the solution with Cu ions, followed by the formation of a metal-organic complex alongside glyphate. The glyphosate contents in the analyte led to a decrease in the conductivity of the transistor on the axis of the smooth film. In turn, the opposite effect was observed on the nanostructured surface, i.e., an increase in conductivity was noted upon the introduction of an analyte. Despite this, the overall sensitivity of the nanostructured device was twice as high as that of the device with a thin film channel. The relative changes in the field-effect transistor (FET) conductivity at maximum glyphosate concentrations of 15 μmol/L reached 19.42% for the nanostructured CuO film and 3.3% for the smooth film.

Development and validation of an integrated microfluidic device with an in-line Surface Enhanced Raman Spectroscopy (SERS) detection of glyphosate in drinking water

Glyphosate, also known as N-(phosphonomethyl)glycine, is one of the most widely used herbicides in the world. However, the controversy surrounding the toxicity of glyphosate and its main breakdown product, aminomethylphosphonic acid (AMPA), remains a serious public concern. Therefore, there is a clear need to develop a rapid, sensitive and automated alternative method for the quantification of glyphosate and AMPA. In this context, surface enhanced Raman spectroscopy (SERS) coupled with a microfluidic system for the determination of glyphosate in tap water was developed, optimized and validated. The design of the microfluidic configuration for this application was built constructed to integrate the synthesis of the SERS substrate through to the detection of the analyte. To optimize the microfluidic setup, a design of experiments approach was used to maximize the SERS signal of glyphosate. Subsequently, an approach based on the European guideline document SANTE/11312/2021 was used to validate the method in the range of 78-480 μg/L using the normalized band intensities. The limit of detection and quantification obtained for glyphosate were 40 and 78 μg/L, respectively. Recoveries were in the range 76-117%, while repeatability and intra-day reproducibility were ≤17%. Finally, the method was also tested for the determination of AMPA in tap water matrix and for the simultaneous detection of AMPA and glyphosate.

Effects of glyphosate on the growth, development, and physiological functions of silkworm, Bombyx mori

Glyphosate is an herbicide widely used worldwide, but whether it is safe to nontarget organisms is controversial. In this study, the lepidopteran model insect silkworm was used to investigate the effects of glyphosate residues. The LC50 (72 h) of glyphosate on silkworm was determined to be 14875.98 mg/L, and after exposure to glyphosate at 2975.20 mg/L (a concentration comparable to that used for weed control in mulberry fields), silkworm growth was inhibited by 9.00%, total cocoon weight was lowered by 10.53%, feed digestibility was decreased by 7.56%, and the activities of alpha-amylase and trypsin were reduced by 10.41% and 21.32%, respectively. Pathological analysis revealed that glyphosate exposure led to significantly damaged midgut, along with thinner basal layer, shedding microvilli, blurred cytoplasmic membrane, and appearance of vacuoles. Exposure to glyphosate also led to accumulation of peroxides in the intestinal tissue; the messenger RNA transcription of SOD, Cu/Zn-SOD, and Mn-SOD was all significantly upregulated by glyphosate treatment for 24 h, while CAT transcription was increased at 24, 48, and 72 h. The activity of SOD was increased significantly at 24 h, while significant activity changes were observed for CAT at 72 and 96 h. These results indicated that exposure to glyphosate caused oxidative stress in the midgut of silkworm and affected the midgut's physiological function. This study provides important insights in evaluating the impact of glyphosate residues in the environment on nontarget organisms.

Bumblebees can be Exposed to the Herbicide Glyphosate when Foraging

Herbicides are the most widely used pesticides globally. Although used to control weeds, they may also pose a risk to bee health. A key knowledge gap is how bees could be exposed to herbicides in the environment, including whether they may forage on treated plants before they die. We used a choice test to determine if bumblebees would forage on plants treated with glyphosate at two time periods after treatment. We also determined whether glyphosate and its degradation product aminomethylphosphonic acid were present as residues in the pollen collected by the bees while foraging. Finally, we explored if floral resources (nectar and pollen) remained present in plants after herbicide treatment. In general bees indiscriminately foraged on both plants treated with glyphosate and controls, showing no avoidance of treated plants. Although the time spent on individual flowers was slightly lower on glyphosate treated plants, this did not affect the bees' choice overall. We found that floral resources remained present in plants for at least 5 days after lethal treatment with glyphosate and that glyphosate residues were present in pollen for at least 70 h posttreatment. Our results suggest that bees could be exposed to herbicide in the environment, both topically and orally, by foraging on plants in the period between herbicide treatment and death. Identifying this route of exposure is a first step in understanding the risks of herbicides to bees. The effects of herbicides on bees themselves are uncertain and warrant further investigation to allow full risk assessment of these compounds to pollinating insects. Environ Toxicol Chem 2022;41:2603-2612. © 2022 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.

Glyphosate residues in soil can modify plant resistance to herbivores through changes in leaf quality

Glyphosate is the most widely used non-selective herbicide in the world. Glyphosate residues in soil can affect plant quality by modifying plant physiology, hormonal pathways and traits, with potential consequences for plants' interactions with herbivores. We explored these indirect effects in the context of plant-herbivore interactions in a perennial, nitrogen-fixing herb. We quantified leaf herbivory for glyphosate-exposed and control plants grown in phosphorus-fertilized and non-fertilized soils, and assessed the impacts of glyphosate treatment on traits related to plant resistance against herbivores (leaf trichome density, leaf mass per area) and performance (aboveground biomass, root:shoot ratio, nodule number, nodule activity). Moreover, we conducted a laboratory feeding experiment to compare the palatability of leaves from glyphosate-exposed and control plants to a generalist mollusc herbivore. Herbivore damage and intensity in situ increased during the growing season regardless of glyphosate or phosphorus treatment. Glyphosate treatment reduced leaf trichome density but had no effect on the other plant traits considered. Herbivore damage was negatively associated with leaf trichome density. The feeding experiment revealed no difference in the feeding probability of mollusc herbivores between glyphosate-exposed and control plants. However, there was an interaction between glyphosate treatment and initial leaf area for leaf consumption by herbivores: leaf consumption increased with increasing leaf area in both groups, but at a lower rate for glyphosate-exposed plants than for control plants. Our results show that glyphosate residues in soil have the potential to indirectly affect aboveground herbivores through changes in leaf quality, which may have mixed consequences for folivore damage.