Dissipation of four fungicides on greenhouse strawberries and an assessment of their risks

Efficacy of Trichoderma spp. and Kosakonia sp. Both Independently and Combined with Fungicides against Botrytis cinerea on Strawberries

Background: The ascomycete Botrytis cinerea is a major pathogen of strawberry, often causing grey mold and significant yield losses. Its management has largely relied on chemical fungicides, which, while effective, can lead to resistant pathogens and harm to non-target organisms and pose health risks. Objectives: This study explored a strategy for minimizing chemical usage by combining biocontrol agents (BCAs) with half-strength fungicide input. Results: In vitro results of fungicide-amended culture plates indicated that the presence of 625 µg mL-1 Azoxystrobin exhibited no growth inhibition of T. atroviride T19 and T. harzianum T16 but increased conidial density of T16 by 90%. Copper (750 µg mL-1) did not suppress the growth of T. virens TVSC or T16 but rather promoted it by 9.5% and 6%, respectively. Additionally, copper increased T16 sporulation by 1.4-fold. Greenhouse trials demonstrated that combining T23 with half-strength Azoxystrobin was as effective as the full dosage in suppressing flower rot. Among the antagonists assessed, Kosakonia sp. exhibited the lowest incidence of fruit rot, whereas T23 resulted in a moderate incidence. Moreover, the combination of T16 or Kosakonia sp. with half-strength copper was almost as effective as the full dosage in reducing fruit rot. Conclusions: Our findings suggest integrating these BCAs in the sustainable management of grey mold in strawberries.

Selected Fungicides as Potential EDC Estrogenic Micropollutants in the Environment

An increasing level of pesticide exposition is being observed as a result of the consumption of large amounts of fruits, vegetables and grain products, which are key components of the vegetarian diet. Fungicides have been classified as endocrine-disrupting compounds, but their mechanisms of action have not yet been clarified. The effect of boscalid (B), cyprodinil (C) and iprodione (I) combined with Tamoxifen (T) and 17β-estradiol (E2) on cell viability, cell proliferation, reporter gene expression, ROS content, the cell membrane's function, cell morphology and antioxidant enzymes gene expression in MCF-7 and T47D-KBluc cell lines were investigated. The cell lines were chosen due to their response to 17β -estradiol. The selected fungicides are commonly used in Poland to protect crops against fungi. Our results revealed that the studied fungicides caused significant increases in cell viability and proliferation, and estrogenic activity was present in all studied compounds depending on their concentrations. Oxidative stress activated uncontrolled cancer cell proliferation by inducing ROS production and by inhibiting antioxidant defense. Our findings verify that the studied fungicides could possibly exhibit endocrine-disrupting properties and exposure should be avoided.

Systemic Colonization of Xanthomonas fragariae Strain YL19 Causing Dry Cavity Rot of Strawberry Crown Tissue in China

Xanthomonas fragariae usually causes angular leaf spot (ALS) of strawberry, a serious bacterial disease in many strawberry-producing regions worldwide. Recently, a new strain of X. fragariae (YL19) was isolated from strawberry in China and has been shown to cause dry cavity rot in strawberry crown. In this study, we constructed a green fluorescent protein (GFP)-labeled Xf YL19 (YL19-GFP) to visualize the infection process and pathogen colonization in strawberries. Foliar inoculation of YL19-GFP resulted in the pathogen migrating from the leaves to the crown, whereas dip inoculation of wounded crowns or roots resulted in the migration of bacteria from the crowns or roots to the leaves. These two invasion types both resulted in the systematic spread of YL19-GFP, but inoculation of a wounded crown was more harmful to the strawberry plant than foliar inoculation. Results increased our understanding of the systemic invasion of X. fragariae, and the resultant crown cavity caused by Xf YL19.

Dissipation, residue and dietary risk assessment of difenoconazole in Rosa roxburghii

Rosa roxburghii is a medicinal and edible plant, which is favored by consumers due to its rich vitamin C content. Residues and potential health risks of difenoconazole in the R. roxburghii ecosystem has aroused a concern considering its extensive use for controlling the powdery mildew of R. roxburghii. In this study, the residue of difenoconazole in R. roxburghii and soil was extracted by acetonitrile, purified by primary secondary amine and detected by liquid chromatography-tandem triple quadrupole mass spectrometry. The average recoveries in R. roxburghii and soil matrix varied from 82.59% to 99.63%, with relative standard deviations (RSD) of 1.14%-8.23%. The limit of quantification (LOQ) and detection (LOD) of difenoconazole in R. roxburghii and soil samples were 0.01 mg/kg. The dissipation of difenoconazole followed well the first-order kinetic, with a half-life of 3.99-5.57 d in R. roxburghii and 4.94-6.23 d in soil, respectively. And the terminal residues were <0.01-2.181 mg/kg and 0.014-2.406 mg/kg, respectively. The chronic and acute risk quotient values of difenoconazole were respectively 0.42% and 4.1%, which suggests that the risk was acceptable and safe to consumers. This study provides a reference for the safe and reasonable use of difenoconazole in R. roxburghii production.

Health risks of dietary ethirimol exposure demand attention in China: A study of nationwide applications

The health risks for dietary exposure after large-scale ethirimol application demand attention to protect the human population from hazardous effects. The occurrence, dissipation and terminal magnitude of ethirimol were revealed by original deposition of <0.005-28.1 mg kg-1, half-lives of 0.6-14.5 d, and terminal concentrations of  spinach > leaf lettuce > pepper > cucumber > papaya > pumpkin > stem lettuce > muskmelon > wax gourd > mango. The high-potential health risks of ethirimol should be continuously emphasized for susceptible children aged 2-13 years, especially those residing in rural areas and presenting increasing vegetable intake.

Exogenous spraying of 4-chlorophenoxyacetic acid sodium salt promotes growth and flavonoid biosynthesis of mulberry leaves (Morus alba L.)

Mulberry (Morus alba L.) leaves are known as an ideal vegetable with good antioxidant effect, which can bring delicious taste and multiple health benefits. In the present study, the effects of 4-Chlorophenoxyacetic acid sodium salt (4-CPANa) treatment on growth and content of flavonoid compounds in mulberry leaves were investigated. Moreover, the changes in the expression levels of genes involved in flavonoid biosynthetic pathways, and the accumulation of important secondary metabolites including rutin (Rut), chlorogenic acid (ChA), isoquercitrin (IQ) and astragalin (Ast), were investigated in mulberry leaves. The results showed that 4-CPANa treatment could significantly promote the differentiation and growth of mulberry, increased shoot number, bud number, leaf fresh weight and leaf area of mulberry compared with control. Besides, the contents of ChA, Rut, IQ and Ast were significantly increased after 4-CPANa (5 mg/L) treatment. Further analysis revealed that 5 mg/L 4-CPANa strongly induced the expression of flavonoid biosynthesis-related genes including flavonoid 3-O-glucosyltransferase (F3GT) gene, chalcone synthase (CHS) gene, 4-xoumarate-CoA ligase (4CL) and phenylalanine ammonia lyase (PAL) gene. In conclusion, exogenous spraying of 4-CPANa provides a new way to improve the medicinal quality and development of mulberry leaf food with high value.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12298-023-01339-z.

Fate and occurrence of indoxacarb during radish cultivation for multi-risk assessment

Agrochemical indoxacarb is an important tool for selective pest control in radish that be consumed globally. A rapid and sensitive analytical method UHPLC-MS/MS was developed for tracing indoxacarb in radish leaves and roots with LOQ of 0.001 mg/kg and RT within 2 min, which were confirmed the satisfied storage stability of indoxacarb in radish matrixes with degradation rates less than 30 %. The occurrence, pharmacokinetics dissipation and concentration variation of indoxacarb were reflected by the original deposition of 2.23-4.12 mg/kg, half-lives of 2.6-8.0 d and terminal magnitude of 0.17 × 10^-2-25.46 mg/kg in radish, and the influencing factors were further illustrated in terms of climate factors, crop cultivars and soil properties. The highest residues of indoxacarb were 25.46 mg/kg in leaves and 0.12 mg/kg in roots, which were higher than international maximum residue limits. A probabilistic model, as well as deterministic model, were introduced to evaluated the health risks of indoxacarb offering a better description for uncertainty. The total chronic dietary risk values of indoxacarb were 146.961-482.065 % in 12 registered crops, of which ADI % in radish was accounted for 19.8 % with risk dilution effects. The unacceptable acute dietary risks of 121.358-220.331 % were observed at 99.9th percentile, whereas the high-potential non-carcinogenic effects were observed over 90th percentile (105.035-1121.943 %). The health risks should be continuously emphasized given the increasing applications and persistent characteristics of indoxacarb, which is vital to protect the human population from hazardous effects, particularly for vulnerable children.

Neurobehavioral Responses and Toxic Brain Reactions of Juvenile Rats Exposed to Iprodione and Chlorpyrifos, Alone and in a Mixture

Herein, male juvenile rats (23th postnatal days (PND)) were exposed to chlorpyrifos (CPS) (7.5 mg/kg b.wt) and/or iprodione (IPD) (200 mg IPD /kg b.wt) until the onset of puberty (60th day PND). Our results demonstrated that IPD and/or CPS exposure considerably reduced locomotion and exploration. However, CPS single exposure induced anxiolytic effects. Yet, neither IPD nor IPD + CPS exposure significantly affected the anxiety index. Of note, IPD and/or CPS-exposed rats showed reduced swimming time. Moreover, IPD induced significant depression. Nonetheless, the CPS- and IPD + CPS-exposed rats showed reduced depression. The individual or concurrent IPD and CPS exposure significantly reduced TAC, NE, and AChE but increased MDA with the maximum alteration at the co-exposure. Moreover, many notable structural encephalopathic alterations were detected in IPD and/or CPS-exposed rat brain tissues. The IPD + CPS co-exposed rats revealed significantly more severe lesions with higher frequencies than the IPD or CPS-exposed ones. Conclusively, IPD exposure induced evident neurobehavioral alterations and toxic reactions in the brain tissues. IPD and CPS have different neurobehavioral effects, particularly regarding depression and anxiety. Hence, co-exposure to IPD and CPS resulted in fewer neurobehavioral aberrations relative to each exposure. Nevertheless, their simultaneous exposure resulted in more brain biochemistry and histological architecture disturbances.

Adsorption, mobility, and degradation of the pesticide propaquizafop in five agricultural soils in China

Propaquizafop is a fatty acid synthetic herbicide used to control annual and perennial grasses. To understand the potential environmental risks of propaquizafop to crops and food safety, the adsorption, mobility, and degradation of propaquizafop in five different soils were studied. At an initial concentration of 5 mg L^-1 propaquizafop, its adsorption equilibrium was reached within 24 h, and the adsorption rates were between 46.98 and 57.76%. The Elovich kinetic model provided the best fit for the kinetic model, with R² values between 0.9882 and 0.9940. For the isothermal adsorption tests, the Freundlich model was used to better fit the adsorption characteristics of propaquizafop in different soils, with R² values between 0.9748 and 0.9885. Increasing the concentration of Ca²⁺ was beneficial for propaquizafop adsorption. In the soil thin-layer chromatography tests, the R_f of propaquizafop in the five soil samples ranged from 0.076 to 0.123. The results of the soil column leaching tests showed that propaquizafop did not migrate in the five soil columns; it was not detected in the leachate of each soil column, and propaquizafop in the soil columns only existed in the 0-5 cm soil layer. The results of soil thin-layer chromatography and soil column leaching tests showed that propaquizafop is a pesticide with a weak migration ability. Under the same environmental conditions, the degradation rate of propaquizafop in different soils followed the order LF fluvo-aquic soil (T_1/2 = 1.41 d) > CS red loam (T_1/2 = 2.76 d) > SX paddy soil (T_1/2 = 3.52 d) > CC black soil (T_1/2 = 5.74 d) > BS ginseng soil (T_1/2 = 7.75 d). Considering the effects of soil moisture, incubation temperature, and microorganisms on propaquizafop degradation in the soil, temperature was found to have the greatest influence on its degradation rate.

Fungicides Cuprozin Progress and SWITCH Modulate Primary and Specialized Metabolites of Strawberry Fruits

Numerous pesticides, including fungicides, are applied every year to crop plants. However, such application may affect the plant metabolism and thus crop quality. Strawberry is an economically important crop, but the fruits are highly susceptible, especially to fungal diseases. In the present study, the effects of two fungicides, Cuprozin progress and SWITCH, on the metabolism of two cultivars and the wild strawberry were tested, focusing on primary (amino acids, (in)organic acids, sugars, total phenolics) and specialized metabolites (aroma volatiles), which determine the fruit flavor. The fungicide treatment significantly affected 11 out of 57 metabolites, while 20 of those differed between strawberry types and 27 were affected by the interaction of both factors. Given these modifications in metabolites in response to the treatments, the taste and quality of the strawberries may pronouncedly change when plants are treated with fungicides.

Effect of microorganisms on degradation of fluopyram and tebuconazole in laboratory and field studies

Nowadays, chemical pesticides are the most widespread measure used to control crop pests and diseases. However, their negative side effects prompted the researchers to search for alternative options that were safer for the environment and people. Pesticide biodegradation by microorganisms seems to be the most reasonable alternative. The aim of the laboratory studies was to assess the influence of Bacillus subtilis and Trichoderma harzianum, used separately and combined together, on fluopyram and tebuconazole degradation. In field studies, the degradation of fluopyram and tebuconazole after the application of the biological preparation in apples was investigated. The results from the laboratory studies show that the greatest decomposition of fluopyram and tebuconazole was observed in tests with T. harzianum in a range of 74.3-81.5% and 44.5-49.2%, respectively. The effectiveness of fluopyram degradation by B. subtilis was 7.5%, while tebuconazole inhibited bacterial cell growth and no degradation was observed. The mixture of microorganisms affected the degradation of fluopyram in a range of 8.3-24.1% and tebuconazole in a range of 6.1-23.3%. The results from the field studies show that degradation increased from 3.1 to 30.8% for fluopyram and from 0.4 to 14.3% for tebuconazole when compared to control samples. The first-order kinetics models were used to simulate the residue dissipation in apples. For the determination of pesticide residues, the QuEChERS method for apple sample preparation was performed, followed by GC-MS/MS technique. Immediately after the treatments, the maximum residue level (MRL) values for tebuconazole were exceeded, and it was equal to 100.7% MRL for the Red Jonaprince variety and 132.3% MRL for the Gala variety. Thus, preharvest time is recommended to obtain apples in which the concentration of pesticides is below the MRL and which can be recognized as safe for humans.

Development of a colloidal gold immunochromatographic test strip for the rapid detection of iprodione

Iprodione is a dicarboximide fungicide that is widely used in agriculture around the world. A reliable and rapid detection method is needed for the on-site monitoring of iprodione residues in a variety of agricultural products. Herein, a colloidal gold immunochromatographic test strip was developed based on a selected coating antigen and a specific monoclonal antibody against iprodione. The particle size of colloidal gold, the preparation technique of the conjugate pad, the composition of the loading buffer, and the extraction solvent were comprehensively optimized for the test strip. A cut-off value of 0.9 mg kg^-1 (50 ng mL^-1) and a visual limit of detection of 0.09 mg kg^-1 (5 ng mL^-1) were achieved in a complex matrix of tobacco. No cross-reactivity was observed for iprodione metabolite and four other widely used pesticides during tobacco growth. Furthermore, the developed colloidal gold immunochromatographic test strip was applied to determine iprodione residues in tobacco samples, and the obtained results were in good agreement with those obtained by liquid chromatography tandem mass spectrometry. Additionally, the test strip was found to be stable afterlong-term storage at 37 °C for two months. The developed colloidal gold immunochromatographic test strip showed excellent accuracy, sensitivity, specificity, and stability, therefore, it is suitable for the rapid detection of iprodione residues in complex matrices.

Synergic interactions between berry polyphenols and gut microbiota in cardiovascular diseases

Now a days, scientific community has been taking initiatives to decrease burden of metabolic disorders including diabetes mellitus, chronic hypertension, cardiovascular diseases and many others. Many nutraceuticals and functional food have a crucial function in preventing and decreasing burden of chronic diseases. Main purpose of the study was to relate association between mechanism of gut microbiota effecting cardiovascular diseases, moreover, to find out advantageous effects of berry polyphenols on gut microbiota and cardiovascular diseases. To summarize, we explore literature for beneficial effects of berry polyphenols by using multiple search engines including Google Scholar, Science Direct and PubMed. Original research article, review articles, experimental trials (human and animal studies) and abstract were also included in the current study based on relevancy to the characteristics of berries and their potential benefit on human health. This detailed review revealed that all classes of berries and their metabolites possess a definite impact on human health by preventing onset of chronic diseases by its anti-inflammatory property, thus, consider as one of the beneficial natural compounds that can be consumed on daily basis to prevent various disorders. There is also a positive association between berry polyphenols and modulation of gut microbiota and their metabolites, furthermore, showed a relationship between gut microbiome and incidence of cardiovascular disease.

Risk Assessment of Triflumezopyrim and Imidacloprid in Rice through an Evaluation of Residual Data

Triflumezopyrim, a novel mesoionic insecticide used to control planthoppers, is a potential substitute for imidacloprid. In this study, triflumezopyrim and imidacloprid residues in rice were determined using a quick, easy, cheap, effective, rugged, and safe procedure combined with ultra-high-performance liquid chromatography–tandem mass spectrometry. The limit of quantification of both triflumezopyrim and imidacloprid was 0.01 mg kg⁻¹, and the average recovery values were 94–104% and 91–106%, with relative standard deviations (RSDs) of 1.1–1.4% and 2.1–3.4% (n = 5), respectively. The consumer protection level was assessed by calculating the theoretical maximum daily intake using the reported maximum residue limits of triflumezopyrim and imidacloprid. The established method was successfully applied to 200 commercial rice samples collected from four provinces in China, and their potential public health risks were assessed using triflumezopyrim and imidacloprid residues. The risk associated with triflumezopyrim and imidacloprid dietary intake was assessed by calculating the national estimated short-term intake and the acute reference dose percentage (%ARfD). The results show that the theoretical maximum daily intake (NEDI) values of triflumezopyrim and imidacloprid in different age and gender groups were 0.219–0.543 and 0.377–0.935 μg kg⁻¹ d⁻¹ bw, and the risk quotient (RQ) values were 0.188–0.467% and 0.365–0.906%, respectively. The acute reference dose (%ARfD) of triflumezopyrim and imidaclopridin ranged from 0.615 to 0.998% and from 0.481 to 0.780%, respectively.

Dissipation rate and exposure risk of trifloxystrobin in dry climatic field environments

The investigation of the magnitude of residues after application of a pesticide is important to ensure consumer safety and is also a regulatory requirement to grant authorization. To address those issues, the behavior of trifloxystrobin residues was investigated in outdoor strawberry and cucumber cultivations, following the recommended and more critical agricultural practices under Egyptian dry climatic conditions. Fruits were collected at several pre-harvest intervals and analyzed with the Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS) extraction protocol followed by liquid chromatography-tandem mass spectrometry. The limit of quantitation of the method was 0.001 mg kg−1. When trifloxystrobin was applied on the field, the half-lives were 2.4 days in cucumbers and 6.2 days in strawberries. Risk assessment showed that chronic and acute dietary exposure to residues following the investigated agricultural patterns are of no concern to consumers.

MDAM-DRNet: Dual Channel Residual Network With Multi-Directional Attention Mechanism in Strawberry Leaf Diseases Detection

The growth of strawberry plants is affected by a variety of strawberry leaf diseases. Yet, due to the complexity of these diseases' spots in terms of color and texture, their manual identification requires much time and energy. Developing a more efficient identification method could be imperative for improving the yield and quality of strawberry crops. To that end, here we proposed a detection framework for strawberry leaf diseases based on a dual-channel residual network with a multi-directional attention mechanism (MDAM-DRNet). (1) In order to fully extract the color features from images of diseased strawberry leaves, this paper constructed a color feature path at the front end of the network. The color feature information in the image was then extracted mainly through a color correlogram. (2) Likewise, to fully extract the texture features from images, a texture feature path at the front end of the network was built; it mainly extracts texture feature information by using an area compensation rotation invariant local binary pattern (ACRI-LBP). (3) To enhance the model's ability to extract detailed features, for the main frame, this paper proposed a multidirectional attention mechanism (MDAM). This MDAM can allocate weights in the horizontal, vertical, and diagonal directions, thereby reducing the loss of feature information. Finally, in order to solve the problems of gradient disappearance in the network, the ELU activation function was used in the main frame. Experiments were then carried out using a database we compiled. According to the results, the highest recognition accuracy by the network used in this paper for six types of strawberry leaf diseases and normal leaves is 95.79%, with an F1 score of 95.77%. This proves the introduced method is effective at detecting strawberry leaf diseases.

Dissipation and Residues of Pyraclostrobin in Rosa roxburghii and Soil under Filed Conditions

Rosa roxburghii has been widely planted in China. Powdery mildew is the most serious disease of R. roxburghii cultivation. Pyraclostrobin was widely used as a novel fungicide to control powdery mildew of R. roxburghii. To assess the safety of pyraclostrobin for use on R. roxburghii fruits, its residue rapid analysis as well as an investigation on its dissipation behaviors and terminal residues in R. roxburghii and soil under field conditions were carried out. The QuEChERS method was simplified using LC−MS/MS detection and combined with liquid−liquid extraction purification to allow determination of pyraclostrobin levels in R. roxburghii fruits and the soil. The fortified recoveries at 0.1~5.0 mg/kg were 93.48~102.48%, with the relative standard deviation of 0.64~3.21%. The limit of detection of the analytical method was 0.16 and 0.15 µg/kg for R. roxburghii fruit and soil, respectively. The effects of different spray equipment and formulations on the persistence of pyraclostrobin in R.roxburghii were as follows: gaston gasoline piggyback agricultural sprayer (5.38 d) > manual agricultural backpack sprayer (3.37 d) > knapsack multi-function electric sprayer (2.91 d), suspension concentrate (SC) (6.78 d) > wettable powder (WP) (5.64 d) > water dispersible granule (WG) (4.69 d). The degradation of pyraclostrobin followed the first-order kinetics and its half-lives in R.roxburghii and soil were 6.20~7.79 days and 3.86~5.95 days, respectively. The terminal residues of pyraclostrobin in R. roxburghii and soil were 0.169~1.236 mg/kg and 0.105~3.153 mg/kg, respectively. This study provides data for the establishment of the maximum residue limit (MRL) as well as the safe and rational use of pyraclostrobin in R. roxburghii production.

Determination, residue analysis, dietary risk assessment and processing of flupyradifurone and its metabolites in pepper under field conditions by LC-MS/MS

An effective method based on liquid chromatography-tandem mass spectrometry was established to determine the concentrations of flupyradifurone, difluoroacetic acid, and 6-chloronicotinic acid in pepper. On the basis of this method, the dissipation, processing factor, and dietary risk of flupyradifurone in pepper were investigated. The results show that the half-life of flupyradifurone in peppers was 2.6-3.8 days. The terminal residual concentration of flupyradifurone in the supervised trials was not higher than the maximum residue limit (MRL) for pepper in the Codex Alimentarius Commission (CAC) (0.9 mg kg^-1 ) with the highest residual values of 0.53 mg kg^-1 . The national estimated daily intake of flupyradifurone was 0.00094 mg kg^-1 , based on the dietary structure of Chinese consumers and the terminal residues under field conditions. The risk quotient for flupyradifurone was 0.012, which was significantly < 1. The processing factor of flupyradifurone in dried pepper was 10.9-14.2, which indicated that drying increased the residual amounts of flupyradifurone in dried pepper, but the residual concentration was still lower than its MRL of 9 mg kg^-1 established by CAC.

Dissipation behavior and dietary risk assessment of pyridaben in open field strawberries and cucumber under Egyptian cultivation conditions

Pyridaben, an inhibitor of mitochondrial electron transport at complex I, is authorized in Egypt as an insecticide/acaricide for strawberries and cucumbers; thus the investigation of residues in the final consumed product is essential as to ensure consumer safety and trade barriers. Therefore, residue trials were conducted according to the in force and more critical Good Agricultural Practices (GAPs) as to investigate the dissipation rate of the compound on both crops and the terminal residues in the final products. Results showed that the residue decline fits a first-order decay process with calculated half-lives of 1 and 6.4 days for cucumbers and strawberries, respectively. Dietary risk assessment was performed based on the risk quotients (RQ) method and the EFSA PRIMo model demonstrating that the dietary exposure to pyridaben residues from cucumber and strawberry consumption, applied either according to the in force or more critical GAPs, does not pose unacceptable health risk to Egyptian and European consumers.

In vitro enantioselective inhibition of the main human CYP450 enzymes involved in drug metabolism by the chiral pesticide tebuconazole

Tebuconazole (TEB) is a chiral triazole fungicide worldwide employed to control plant pathogens and preserve wood. People can be exposed to TEB either through diet and occupational contamination. This work investigates the in vitro inhibitory potential of rac-TEB, S-(+)-TEB, and R-(-)-TEB over the main cytochrome P450 enzymes (CYP450) using human liver microsomes to predict TEB in vivo inhibition potential. The IC₅₀ values showed that in vitro inhibition was enantioselective for CYP2C9, CYP2C19, and CYP2D6, but not for CYP3A4/5. Despite enantioselectivity, rac-TEB and its single enantiomers were always classified in the same category. The inhibition mechanisms and constants were determined for rac-TEB and it has shown to be a mixed inhibitor of CYP3A4/5 (K_i = 1.3 ± 0.3 μM, αK_i = 3.2 ± 0.5 μM; K_i = 0.6 ± 0.3 μM, αK_i = 1.3 ± 0.3 μM) and CYP2C9 (K_i = 0.7 ± 0.1 μM, αK_i = 2.7 ± 0.5 μM), and a competitive inhibitor of CYP2D6 (K_i = 11.9 ± 0.7 μM) and CYP2C19 (K_i = 0.23 ± 0.02 μM), respectively, suggesting that in some cases, rac-TEB has a higher or comparable inhibitory potential than well-known strong inhibitors of CYP450 enzymes, especially for CYP2C9 and CYP2C19. In vitro-in vivo extrapolations (IVIVE) were conducted based on the results and data available in the literature about TEB absorption and metabolism. R₁ values were estimated based on the Food and Drug Administration guideline and suggested that in a chronic oral exposure scenario considering the acceptable daily intake dose proposed by the European Food and Safety Authority, the hypothesis of rac-TEB to inhibit the activities of CYP3A4/5, CYP2C9, and CYP2C19 in vivo and cause pesticide-drug interactions cannot be disregarded.

Iprodione and/or chlorpyrifos exposure induced testicular toxicity in adult rats by suppression of steroidogenic genes and SIRT1/TERT/PGC-1α pathway

There is cumulative evidence that iprodione (IPR) fungicide and chlorpyrifos (CPF) insecticide are endocrine disruptors that can evoke reproductive toxicity. Yet, the underlying mechanisms are still unclear. Besides, the outcomes of their co-exposure to male sexual behavior and male fertility are still unknown. The effects of IPR (200 mg/kg b.wt) and CPF (7.45 mg/kg b.wt) single or mutual exposure for 65 days on sexual behavior, sex hormones, testicular enzymes, testis, and accessory sex gland histomorphometric measurements, apoptosis, and oxidative stress biomarkers were investigated. In addition, expression of nuclear receptor subfamily group A (NR5A1), 17β-hydroxysteroid dehydrogenase (HSD17B3), silent information regulator type-1 (SIRT1), telomerase reverse transcriptase (TERT), and peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α) genes has been assessed. Our results revealed that the individual or concurrent IPR and CPF exposure significantly disturb the sexual behavior, semen characteristics, testicular enzymes, and male hormones level. Oxidative stress caused by IPR and CPF activates apoptosis by inducing Caspase-3 and reducing Bcl-2. Downregulation of HSD17B3, NR5A1, and SIRT1/TERT/PGC-1α pathway was evident. Of note, most of these disturbances were exaggerated in rats co-exposed to IPR and CPF compared to IPR or CPF alone. Conclusively, our findings verified that IPR and CPF possibly damage the male reproductive system, and concurrent exposure should be avoided.

Dissipation kinetics and processing behavior of boscalid and pyraclostrobin in greenhouse dill plant (Anethum graveolens L.) and soil

BACKGROUND

Determining the environmental behavior and fate of chemical compounds during technological processing of plants is a task of great significance nowadays. However, the current knowledge is still incomplete for unique herbal matrices belonging to minor crops. The research in this article presents, for the first time, the dissipation kinetics and processing behavior of carboxamide boscalid (BOS) and stobilurin pyraclostrobin (PYR) fungicides during glasshouse dill (Anethum graveolens L.) cultivation.

RESULTS

The half-lives (t_1/2 ) of BOS and PYR after application at the recommended and double dosage were in the range: 1.62-2.01 days in plant and 2.08-4.85 days in soil, respectively. The processing behavior in dill was estimated after washing, hot air drying and drying in sunlight without/with pretreatment. Processing factors (PFs) were above 1 after drying (PF = 1.24-1.39 hot air; PF = 1.15-1.28 sunlight) and below this value when the washing step was applied (PF = 0.31-0.42 hot air; PF = 0.21-0.34 sunlight), indicating the highest effectiveness of reduction, up to 73% BOS and 79% PYR.

CONCLUSION

BOS/PYR residues at pre-harvest intervals after both doses were below European Union (EU) maximum residue limits (MRLs). The highest effectiveness was noted for drying carried out with the washing step, which has a great influence on the concentration of residues in the final product. The findings can supplement PF databases not set for minor crops and can be used to establish MRLs and determine human exposures more accurately in risk assessment studies. © 2021 Society of Chemical Industry.

Dissipation, accumulation and risk assessment of fungicides after repeated spraying on greenhouse strawberry

Repeated spraying of fungicides is a common phenomenon in greenhouse strawberry cultivation, and the continuous harvest of strawberries makes them prone to contamination by accumulated fungicides. Despite this, very few residue safety assessments of fungicides on greenhouse strawberries are conducted after repeated spraying of fungicides, and no research exists on fungicide dissipation and accumulation mechanism. Therefore, the present study investigated the dissipation and accumulation of four fungicides (pyraclostrobin, pyrimethanil, procymidone, and cyprodinil) after two typical repeated sprayings (a single fungicide repeated spraying and two fungicides sprayed using an alternate repeated technique). The half-life of pyraclostrobin after three single repeated sprayings was 18 d; however, its average half-life decreased to 9 d after alternate repeated spraying with cyprodinil. The shortened half-life may be attributed to cyprodinil water solution washing during alternate repeated spraying. The other three fungicides showed similar half-lives after single and alternate repeated spraying, following the order of cyprodinil (12 d and 10 d) > procymidone (11 d and 10 d) > pyrimethanil (6 d and 7 d). The octanol-water partition coefficient was a more efficient indicator of the half-life order of the fungicides than vapor pressure and water solubility. Pyraclostrobin showed the highest deposition efficiency but negligible residue accumulation; further, the residue accumulation of the four fungicides followed the order of procymidone > cyprodinil > pyrimethanil > pyraclostrobin after both single and alternate repeated spraying. A safety assessment demonstrated that the maximum number of times cyprodinil could be sprayed after single spraying was one; however, this number doubled after alternate spraying. The risk of exceeding the maximum residue limits of the fungicides on greenhouse strawberries decreased; however, the combined dietary risks of fungicides after alternate spraying might be high. Alternate repeated spraying of procymidone and pyrimethanil may be the optimal repeated spraying combination for greenhouse strawberries.

Residue analysis and dietary exposure risk assessment of acibenzolar-S-methyl and its metabolite acibenzolar acid in potato, garlic, cabbage, grape and tomato

Acibenzolar-S-methyl (ASM) is one of the most effective plant resistance activators and protects against a broad spectrum of fungal, bacterial and viral pathogens. A rapid, efficient and high-throughput analysis method for ASM and its metabolite acibenzolar acid in fruits and vegetables was developed using potato, garlic, cabbage, grape and tomato as representative commodities by modified QuEChERS and UPLC-MS/MS. The modified procedure showed satisfying recoveries (70-108%) fortified in the range of 0.01-1 mg/kg with relative standard deviations (RSDs) lower than 17.7%. With the established analytical method, the dietary risk of ASM in fruits and vegetables from Chinese markets were further monitored using risk quotient (RQ) method. The RQ value based on ASM residue in China are far less than 1, elucidating that the potential health risk induced by ASM ingestion for Chinese population is not significant. Comparing the residue and risk assessment results of ASM in agricultural products in China to those in Codex, the maximum residue limits (MRLs) for ASM on garlic, cabbage and tomato established by CAC (Codex Alimentarius Commission) can be safely adopted in China, whereas the MRLs on potato and grape in China should be proposed as 0.01 mg/kg.

Degradation, adsorption and leaching of phenazine-1-carboxamide in agricultural soils

Phenazines, a large group of nitrogen-containing heterocycles with promising bioactivities, can be widely used as medicines and pesticides. But phenazines also generate toxicity risks due to their non-selective DNA binding. The environmental fate of phenazines in soils is the key to assess their risks; however, hitherto, there have been very few related studies. Therefore in the present study, the degradation, adsorption and leaching behaviors of a typical natural phenazine-phenazine-1-carboxamide (PCN) in agricultural soils from three representative places in China with different physicochemical properties were, for the first time, systematically studied in laboratory simulation experiments. Our results indicated that the degradation of PCN in all the tested soils followed the first order kinetics, with half-lives ranging from 14.4 to 57.8 d under different conditions. Soil anaerobic microorganisms, organic matter content and pH conditions are important factors that regulating PCN degradation. The adsorption data of PCN were found to be well fitted using the Freundlich model, with the r² values above 0.978. Freundlich adsorption coefficient K_f of PCN ranged from 5.75 to 12.8 [(mg/kg)/(mg/L)^1/n] in soils. The retention factor R_f values ranged from 0.0833 to 0.354, which means that the mobility of PCN in the three types of soil is between immobile to moderately mobile. Our results demonstrate that PCN is easily degraded, has high adsorption affinity and low mobility in high organic matter content and clay soils, thus resulting in lower risks of contamination to groundwater systems. In contrast, it degraded slowly, has low adsorption affinity and moderately mobile in soils with low organic matter and clay content, therefore it has higher polluting potential to groundwater systems. Overall, these findings provide useful insights into the future evaluation of environmental as well as health risks of PCN.

Residue behavior and removal of iprodione in garlic, green garlic, and garlic shoot

BACKGROUND

Iprodione is considered to be an endocrine-disturbing pesticide, which could harm consumers. The garlic crop has three edible parts: the garlic, the green garlic, and the garlic shoot, which correspond to different stages of its growth. In this study, iprodione residue dissipation and distribution in these three edible parts were investigated, and dietary risk was evaluated.

RESULTS

Iprodione residues were present in these samples in the following order: green garlic > garlic shoot > > garlic. The dissipation of iprodione in green garlic was slow with a half-life of 5.82-19.25 days. A very high RQ_chronic value of 207.35-407.30% suggested that the residual iprodione in green garlic had an unacceptable level of risk. Iprodione residue was significantly eliminated (59-90%) by an alkaline solution. The order for removing iprodione by soaking was the alkaline solutions (0.5% and 2% NaHCO₃ ) > the acidic solutions (5% and 10% of vinegar) ≈ the neutral solutions (the 1% and 2% of table salt) > tap water. Processing factors (PFs) were <1, indicating that processing could decrease the iprodione residue level.

CONCLUSION

This work could contribute to establishing maximum residue limits (MRLs) for iprodione in garlic, green garlic, and garlic shoots, and could provide guidance on the safe and appropriate use of iprodione in the garlic crop. © 2020 Society of Chemical Industry.

Dissipation behavior, residue distribution and dietary risk assessment of cyromazine, acetamiprid and their mixture in cowpea and cowpea field soil

BACKGROUND

Cyromazine and acetamiprid are widely applied as pesticides in agriculture, causing increasing concerns about their residues in crops. In this study, cyromazine, acetamiprid and their mixture were applied to cowpea to investigate their degradation dynamics and perform a dietary risk assessment.

RESULTS

The dissipation behavior of cyromazine and acetamiprid in the single- and mixed-pesticide groups followed first-order kinetics, with a linear correlation coefficient of 0.910 to 0.987. The half-lives of cyromazine and acetamiprid were 1.56-11.18 days in the four different matrices. The half-life of cyromazine in the mixed-pesticide group was similar to or even shorter than that in the single-pesticide group. The highest levels of cyromazine and acetamiprid in cowpea occurred with a preharvest interval of 7 days and after two or three applications. These levels are below the maximum residue limits recommended by the Chinese Ministry of Agriculture for cyromazine and acetamiprid in cowpea. The risk quotient of cyromazine and acetamiprid ranged from 0.0018 to 0.0418, and the national estimated short-term intake values of the cyromazine and acetamiprid were far below the acute reference dose as recommended by the European Food Safety Authority.

CONCLUSION

These results suggest that the use of cyromazine and acetamiprid and a cyromazine-acetamiprid mixture in cowpea is safe under the Good Agricultural Practices for Chinese fields, and the use of a cyromazine-acetamiprid mixture affords even better results than the application of cyromazine alone. Moreover, the residue dynamics information will support the label claims for the application of cyromazine, acetamiprid and a cyromazine-acetamiprid mixture to cowpea fruit. © 2020 Society of Chemical Industry.

Dissipation of sixteen pesticide residues from various applications of commercial formulations on strawberry and their risk assessment under greenhouse conditions

Twelve commercial pesticide formulations containing sixteen active ingredients were applied on greenhouse strawberries at recommended and double doses. The dynamics and dietary risk analysis were investigated. A modified QuEChERS method based on the use of multi-walled carbon nanotubes (MWCNTs) as adsorbent followed by LC-MS/MS and GC-MS/MS detection was utilized for sample analysis. The half-lives of studied pesticides were 4.6-12.6 days and 3.8-15.8 days from two application doses. Dietary levels from the residue concentrations of the individual pesticides at harvest was contrasted with the acceptable daily intake (ADI) and acute reference dose (ARfD). The dietary risk assessment adopt the risk quotient (RQ) for chronic risk and risk probability (RP) for long-term dietary intake risk, respectively. The dietary risk induced by the studied pesticide residues in strawberry was acceptable for consumers except the pesticide fumigants. The pesticide residues at different pre-harvest intervals (PHIs) under greenhouse conditions were compared with the established maximum residue limits (MRLs). To reduce the residue levels and potential safety risk, a longer PHI or reduced application rates should be conducted.

Adsorption and Desorption of Carbendazim and Thiamethoxam in Five Different Agricultural Soils

The adsorption and desorption behaviors of carbendazim (CBD) and thiamethoxam (TMX) were systematically studied in five different agricultural soils. The adsorption and desorption isotherms of CBD and TMX in the five different soils were fitted well by the Freundlich model. The Freundlich adsorption coefficient (K_f^ads) and Freundlich desorption coefficient (K_f^des) of CBD in the five different soils were 1.46-19.53 and 1.81-3.33, respectively. The corresponding values of TMX were 1.19-4.03 and 2.07-6.45, respectively. The adsorption affinity and desorption ability of the five different soils for CBD and TMX depended mainly on soil organic matter content (OMC) and cation exchange capacity (CEC). Desorption hysteresis occurred in the desorption process of CBD and TMX in the five different agricultural soils, especially for TMX. It is concluded that the adsorption-desorption ability of CBD was much higher than that of TMX in the five different agricultural soils, which was attributed to soil OMC and CEC.

Evaluation of photolysis and hydrolysis of pyraclostrobin in aqueous solutions and its degradation products in paddy water

This study evaluated the hydrolysis and photolysis kinetics of pyraclostrobin in an aqueous solution using ultra-high-performance liquid chromatography-photodiode array detection and identified the resulting metabolites of pyraclostrobin by hydrolysis and photolysis in paddy water using high-resolution mass spectrometry coupled with liquid chromatography. The effect of solution pH, metal ions and surfactants on the hydrolysis of pyraclostrobin was explored. The hydrolysis half-lives of pyraclostrobin were 23.1-115.5 days and were stable in buffer solution at pH 5.0. The degradation rate of pyraclostrobin in an aqueous solution under sunlight was slower than that under UV photolysis reaction. The half-lives of pyraclostrobin in a buffer solution at pH 5.0, 7.0, 9.0 and in paddy water were less than 12 h under the two light irradiation types. The metabolites of the two processes were identified and compared to further understand the mechanisms underlying hydrolysis and photolysis of pyraclostrobin in natural water. The extracted ions obtained from paddy water were automatically annotated by Compound Discoverer software with manual confirmation of their fragments. Two metabolites were detected and identified in the pyraclostrobin hydrolysis, whereas three metabolites were detected and identified in the photolysis in paddy water.

Dissipation of Pre-Harvest Pesticides on ‘Clementine’ Mandarins after Open Field Application, and Their Persistence When Stored under Conventional Postharvest Conditions

The dissipation of field-applied difenoconazole, imidacloprid, pyraclostrobin and spinosad on Clementine mandarins (Citrus clementina Hort. ex Tan.) under controlled conditions throughout the citrus production chain was assessed. At harvest, 42 days after application, the dissipation of these pesticides were 80, 92, and 48% for difenoconazole, imidacloprid, pyraclostrobin, respectively, and spinosad was below the level of detectability. At day 28 after application, spinosad was no longer detected. The model equations that best describe the dissipation curves of these pesticides on Clementine mandarins showed different patterns. Their half-life on Clementine, calculated by the best-fitted experimental data, were 19.2 day (1st-order model) for difenoconazole, 4.1 day (Root Factor (RF) 1st-order model) for imidacloprid, 39.8 day (2nd-order model) for pyraclostrobin and 5.8 day (1st-order model) for spinosad. These results are the first record of pyraclostrobin persistence on mandarins, showing a longer half-life in this matrix than those reported for any other fruit. The treated fruit were harvested and submitted to the usual postharvest treatments: first, a hypochlorite drenching was performed; as a second step, imazalil and wax were applied, and then the mandarins were stored at 4 °C. After 32 days, cold storage caused no significant effects on the residue levels of the four pesticides compared with those determined on freshly harvested mandarins. All residues were below their Codex and European Union (EU) maximum residue limit (MRL) for mandarin since the spray application day.

Screening for suitable chemical acaricides against two-spotted spider mites, Tetranychus urticae, on greenhouse strawberries in China

Effective and safe acaricides based on scientific data are needed for that no chemical acaricides has been registered for the control of two-spotted spider mite in strawberry crops in China. To identify suitable acaricides, the efficacy, persistence, and toxicity of eight acaricides (hexythiazox, fenpyroximate, chlorfenapyr, propargite, etoxazole, bifenazate, spirodiclofen, and pyridaben) on greenhouse strawberries were tested. The eight acaricides were ranked, from highest average efficacy at the recommended dosage to lowest, as follows: etoxazole > bifenazate > fenpyroximate > propargite > spirodiclofen > pyridaben > hexythiazox> chlorfenapyr. The average recoveries of the eight acaricides at the spiking levels of 0.05 and 0.5 mg/L ranged from 72.4% to 108.1% (relative standard deviation, 1.3-8.8%). The concentrations of hexythiazox, fenpyroximate, etoxazole, bifenazate, spirodiclofen, and pyridaben at 5 days after application were lower than the maximum residue limits (MRLs) specified by China, the European Union (EU), the Codex Alimentarius Commission, and Japan, but those of chlorfenapyr and propargite residues were 8.8 and 1.9 times higher than the MRLs in the EU. Only propargite posed a high chronic dietary risk to humans. Pyridaben and chlorfenapyr showed unacceptable ecotoxicology risks for honeybees (hazard quotient values of > 50). The recommended acaricides to control spider mites in greenhouse-grown strawberry crops are etoxazole, bifenazate, fenpyroximate, spirodiclofen, and hexythiazox based on the efficacy, persistence and toxicity.

Positive effects of an oil adjuvant on efficacy, dissipation and safety of pyrimethanil and boscalid on greenhouse strawberry

Methylated vegetable oil adjuvants can enhance initial deposition and decrease the required dosages of pesticides sprayed on plants, so an oil adjuvant mixed with fungicides were used to prevent and control gray mold in greenhouse strawberry. As the persistence and dietary exposure risks from fungicides on strawberries after using adjuvants have not been assessed, the efficacy, dissipation and safety of pyrimethanil and boscalid in the presence and absence of a methylated vegetable oil adjuvant were evaluated. To better describe the actual use of fungicides in greenhouse strawberry, twice repeated application of fungicides were conducted follower by an optimized QuEChERS pre-treatment method. When applied at 60% of their recommended dosages with the adjuvant, the efficacy of pyrimethanil and boscalid for gray mold was similar to that shown by the treatment of 100% fungicides in absence of the adjuvant based on Duncan's Multiple-Range test, and their average residues increased to 89.0% and 89.3%, respectively. The adjuvant enhanced the accumulation effect of pyrimethanil residue by 31.7% after repeated applications, and the half-lives were similar (5.2 and 4.2 d). The adjuvant had comparable accumulation effects (1.75 and 1.83) and similar half-lives (5.4 and 5.5 d) for boscalid. In absence of adjuvant, the risk quotients (RQs) of pyrimethanil (0.41 and 0.33) and boscalid (0.49 and 0.63) after twice applications at pre-harvest interval were lower than 1. Adding the methylated vegetable oil adjuvant to fungicides would result in unprolonging half-life and acceptably low dietary exposure risk on strawberries, but lower dosage of fungicides were used.

Residue behavior and risk assessment of imidacloprid applied on greenhouse-cultivated strawberries under different application conditions

A risk assessment for imidacloprid applied on strawberries under different conditions was performed after residue determination using the quick, cheap, effective, rugged, and safe (QuEChERS) method. The application conditions were varied according to the applied dosage, addition of a plant oil or organosilicon surfactant, water volume, and sprayer type. The degradation dynamics of imidacloprid on strawberries followed first-order kinetics. At applied doses of 30-60 g a.i. ha^-1, the half-lives of imidacloprid were 2.89-3.46, 1.98-3.65, and 2.57-2.77 days after application without a surfactant or with a plant oil or organosilicon surfactant, respectively. For water volumes of 112.5, 225, 450, 675, and 900 L ha^-1, the half-lives of imidacloprid applied in the presence of the plant oil surfactant were 3.30, 7.70, 5.33, 7.70, and 6.30 days, respectively. The half-lives after application with a knapsack mist duster, electric sprayer, and manual sprayer were 2.16, 5.77, and 7.70 days, respectively. The health risk assessment revealed risk quotients less than 1 in all cases, indicating that the application of imidacloprid poses a low health risk to humans after a pre-harvest interval of 10 days under our application conditions. The risk assessment results can provide reference data for setting a reasonable maximum residue limit for imidacloprid on strawberries in China.

Dissipation behaviour, residue distribution and dietary risk assessment of tetraconazole and kresoxim-methyl in greenhouse strawberry via RRLC-QqQ-MS/MS technique

20% commercial suspension emulsion (SE) of (8% tetraconazole + 12% kresoxim-methyl), as a pre-registered product in China, was firstly investigated under Chinese greenhouse-field conditions. A MWCNTs-based QuEChERS method for simultaneous determination of tetraconazole and kresoxim-methyl in strawberry was developed and validated via RRLC-QqQ-MS/MS. On basis of this method, the dissipation behaviours, residue distributions and dietary risk probability of these fungicides in strawberry were further investigated for food safety. The dissipations of tetraconazole and kresoxim-methyl followed first-order kinetics with the half-lives of 8.0-18.2 days. The highest residues (HRs) of these fungicides in the supervised trials at the pre-harvest interval (PHI, 3 days) were below 0.8970mgkg^-1. The total national estimated daily intake (NEDI) of tetraconazole and kresoxim-methy in strawberry at the PHI 3day was 0.2784mg and 0.4031mg, respectively, based on Chinese dietary pattern and terminal residue distributions under good agricultural practices (GAP) conditions. The risk quotients (RQs) of tetraconazole and kresoxim-methy at PHI 3 days were below 82.7% and 1.6%, respectively, showing that the evaluated strawberry exhibited an acceptably low dietary risk to consumers. The current study could not only guide reasonable usage of the formulation, but also facilitate the setting of maximum residue limits (MRLs) of tetraconazole in strawberry.

Residue analysis and risk assessment of tebuconazole in jujube (Ziziphus jujuba Mill)

In this study, a sensitive and reliable analytical method, based on a modified Quick, Easy, Cheap, Effective, Rugged and Safe procedure, was established for determination of tebuconazole in jujube. After extraction with acetonitrile, the samples were cleaned up by dispersive solid-phase extraction with primary secondary amine, and determined by high-performance liquid chromatography tandem mass spectrometry. At fortification levels of 0.01, 0.1 and 2.0 mg kg^-1 , the average recoveries of tebuconazole in jujube were in the range 97.6-101.9%, with relative standard deviations of 1.5-3.5%. The dissipation and residual levels of tebuconazole in jujube under field conditions were investigated. Tebuconazole dissipated relatively slowly in jujube, with a half-life of 33.0 days. The terminal residue experiments of tebuconazole in jujube were conducted in four locations in China and the risk was evaluated using risk quotients (RQ). RQ values were found to be significantly lower than RQ = 1, indicating that the risk to human health of using the recommended doses of tebuconazole in jujube was not significant. This study could provide guidance for the safe and reasonable use of tebuconazole in jujube and serve as a reference for the establishment of limit of maximum residue in China.

Changes in soil microbial community structure and function associated with degradation and resistance of carbendazim and chlortetracycline during repeated treatments

The degradation characteristics of carbendazim (CBD) and chlortetracycline (CTC) in individual and combined treatments, and dynamics of soil microbial structural and functional diversity as well as their potential relations were studied during three repeated treatments using different concentrations. The results showed that the degradation half-life of CBD at concentrations of 3mg/kg and 6mg/kg obviously increased, but that of CTC at levels of 1mg/kg and 10mg/kg decreased with increasing treatment frequency. Soil microbial activity and functional diversity displayed the suppression trend in CBD treatment and the suppression-recovery-stimulation trend in CTC and CBD+CTC treatments, which were consistent with the findings of decreased degradation rate of CBD and increased degradation rate of CTC. 16S amplicon sequencing analysis revealed five potentially dominant CTC-resistant microbial genera including Bacillus, Actinobacillus, Pseudomonas, Mycobacterium, and Corynebacterium, which may mainly carry major facilitator superfamily transporter protein, ribosomal protection protein, and other proteins encoded by tetA, tetB, tetC, tetH, tetL, tetM, tetO, tetV, tetW, tetX, tetZ, tet33, and tet39. These five dominant genera may jointly contribute to the elevated bacterial community resistance to CTC. Our findings provided a better understanding of microbial community structure and function changes in repeatedly treated soils with CBD and CTC.

Bioactive Compounds and Antioxidant Activity in Different Types of Berries

Berries, especially members of several families, such as Rosaceae (strawberry, raspberry, blackberry), and Ericaceae (blueberry, cranberry), belong to the best dietary sources of bioactive compounds (BAC). They have delicious taste and flavor, have economic importance, and because of the antioxidant properties of BAC, they are of great interest also for nutritionists and food technologists due to the opportunity to use BAC as functional foods ingredients. The bioactive compounds in berries contain mainly phenolic compounds (phenolic acids, flavonoids, such as anthocyanins and flavonols, and tannins) and ascorbic acid. These compounds, either individually or combined, are responsible for various health benefits of berries, such as prevention of inflammation disorders, cardiovascular diseases, or protective effects to lower the risk of various cancers. In this review bioactive compounds of commonly consumed berries are described, as well as the factors influencing their antioxidant capacity and their health benefits.