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Goetz A, Ryan N, Sauve-Ciencewicki A, Lord CC, Hilton GM, Wolf DC. Assessing human carcinogenicity risk of agrochemicals without the rodent cancer bioassay. FRONTIERS IN TOXICOLOGY 2024; 6:1394361. [PMID: 38933090 PMCID: PMC11200232 DOI: 10.3389/ftox.2024.1394361] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2024] [Accepted: 05/20/2024] [Indexed: 06/28/2024] Open
Abstract
The rodent cancer bioassays are conducted for agrochemical safety assessment yet they often do not inform regulatory decision-making. As part of a collaborative effort, the Rethinking Carcinogenicity Assessment for Agrochemicals Project (ReCAAP) developed a reporting framework to guide a weight of evidence (WOE)-based carcinogenicity assessment that demonstrates how to fulfill the regulatory requirements for chronic risk estimation without the need to conduct lifetime rodent bioassays. The framework is the result of a multi-stakeholder collaboration that worked through an iterative process of writing case studies (in the form of waivers), technical peer reviews of waivers, and an incorporation of key learnings back into the framework to be tested in subsequent case study development. The example waivers used to develop the framework were written retrospectively for registered agrochemical active substances for which the necessary data and information could be obtained through risk assessment documents or data evaluation records from the US EPA. This exercise was critical to the development of a framework, but it lacked authenticity in that the stakeholders reviewing the waiver already knew the outcome of the rodent cancer bioassay(s). Syngenta expanded the evaluation of the ReCAAP reporting framework by writing waivers for three prospective case studies for new active substances where the data packages had not yet been submitted for registration. The prospective waivers followed the established framework considering ADME, potential exposure, subchronic toxicity, genotoxicity, immunosuppression, hormone perturbation, mode of action (MOA), and all relevant information available for read-across using a WOE assessment. The point of departure was estimated from the available data, excluding the cancer bioassay results, with a proposed use for the chronic dietary risk assessment. The read-across assessments compared data from reliable registered chemical analogues to strengthen the prediction of chronic toxicity and/or tumorigenic potential. The prospective case studies represent a range of scenarios, from a new molecule in a well-established chemical class with a known MOA to a molecule with a new pesticidal MOA (pMOA) and limited read-across to related molecules. This effort represents an important step in establishing criteria for a WOE-based carcinogenicity assessment without the rodent cancer bioassay(s) while ensuring a health protective chronic dietary risk assessment.
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Affiliation(s)
- Amber Goetz
- Syngenta Crop Protection LLCGreensboro, NC, United States
| | - Natalia Ryan
- Syngenta Crop Protection LLCGreensboro, NC, United States
| | | | - Caleb C. Lord
- Syngenta Crop Protection LLCGreensboro, NC, United States
| | - Gina M. Hilton
- PETA Science Consortium International e.V., Stuttgart, Germany
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Hu T, Fang H, Pan Q, Xu H, Lv T, Fan X, Wang Y, Guo Y, Mou L, Xu J, Zhu J, Matsumoto H, Wang M. Seed microbiome-mediated herbicide resistance evolution in weeds. THE NEW PHYTOLOGIST 2024; 242:333-343. [PMID: 38062878 DOI: 10.1111/nph.19459] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2023] [Accepted: 11/17/2023] [Indexed: 03/22/2024]
Abstract
See also the Commentary on this article by Zhang et al., 242: 327–330.
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Affiliation(s)
- Tingting Hu
- Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Ministry of Agriculture, Institute of Pesticide and Environmental Toxicology, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, 310058, China
- State Key Laboratory of Rice Biology and Breeding, Zhejiang University, Hangzhou, 310058, China
| | - Hongda Fang
- Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Ministry of Agriculture, Institute of Pesticide and Environmental Toxicology, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, 310058, China
- State Key Laboratory of Rice Biology and Breeding, Zhejiang University, Hangzhou, 310058, China
| | - Qianqian Pan
- Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Ministry of Agriculture, Institute of Pesticide and Environmental Toxicology, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, 310058, China
- State Key Laboratory of Rice Biology and Breeding, Zhejiang University, Hangzhou, 310058, China
| | - Haorong Xu
- Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Ministry of Agriculture, Institute of Pesticide and Environmental Toxicology, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, 310058, China
- State Key Laboratory of Rice Biology and Breeding, Zhejiang University, Hangzhou, 310058, China
| | - Tianxing Lv
- Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Ministry of Agriculture, Institute of Pesticide and Environmental Toxicology, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, 310058, China
- State Key Laboratory of Rice Biology and Breeding, Zhejiang University, Hangzhou, 310058, China
| | - Xiaoyan Fan
- Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Ministry of Agriculture, Institute of Pesticide and Environmental Toxicology, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, 310058, China
- State Key Laboratory of Rice Biology and Breeding, Zhejiang University, Hangzhou, 310058, China
| | - Yue Wang
- Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Ministry of Agriculture, Institute of Pesticide and Environmental Toxicology, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, 310058, China
- State Key Laboratory of Rice Biology and Breeding, Zhejiang University, Hangzhou, 310058, China
| | - Yichun Guo
- Phytobiome Ecological Science & Technology, Shanghai, 200122, China
| | - Lei Mou
- Phytobiome Ecological Science & Technology, Shanghai, 200122, China
| | - Jiayu Xu
- Phytobiome Ecological Science & Technology, Shanghai, 200122, China
| | - Jinwen Zhu
- Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Ministry of Agriculture, Institute of Pesticide and Environmental Toxicology, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, 310058, China
- State Key Laboratory of Rice Biology and Breeding, Zhejiang University, Hangzhou, 310058, China
| | - Haruna Matsumoto
- Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Ministry of Agriculture, Institute of Pesticide and Environmental Toxicology, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, 310058, China
- State Key Laboratory of Rice Biology and Breeding, Zhejiang University, Hangzhou, 310058, China
| | - Mengcen Wang
- Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Ministry of Agriculture, Institute of Pesticide and Environmental Toxicology, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, 310058, China
- State Key Laboratory of Rice Biology and Breeding, Zhejiang University, Hangzhou, 310058, China
- Global Education Program for AgriScience Frontiers, Graduate School of Agriculture, Hokkaido University, Sapporo, Japan
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Sun P, Niu L, Lan X, Yu H, Cui H, Chen J, Li X. Enhanced metabolic resistance mechanism endows resistance to metamifop in Echinochloa crus-galli (L.) P. Beauv. PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY 2023; 197:105656. [PMID: 38072531 DOI: 10.1016/j.pestbp.2023.105656] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2023] [Revised: 10/16/2023] [Accepted: 10/18/2023] [Indexed: 12/18/2023]
Abstract
Barnyardgrass (Echinochloa crus-galli (L.) P. Beauv.), one of the worst weeds in paddy fields in China, has been frequently reported evolving resistance to acetyl-CoA carboxylase (ACCase) inhibiting herbicides. However, in the previous research, more attention was paid to target-site resistance (TSR) mechanisms, the non-target-site resistance (NTSR) mechanisms have not been well-established. In this study, the potential mechanism of resistance in a metamifop-resistant E. crus-galli collected from Kunshan city, Jiangsu Province, China was investigated. Dose-response assays showed that the phenotypic resistant population (JS-R) has evolved 4.3-fold resistance to metamifop compared with the phenotypic susceptible population (YN-S). The ACCase CT gene sequencing and relative ACCase gene expression levels studies showed that no mutations were detected in the ACCase CT gene in both YN-S and JS-R, and there was no significant difference in the relative ACCase gene expression between YN-S and JS-R. After the pre-processing of glutathione-S-transferase (GSTs) inhibitor NBD-Cl, the resistance level of JS-R to metamifop was reversed 18.73%. Furthermore, the GSTs activity of JS-R plants was significantly enhanced compared to that of YN-S plants. UPLC-MS/MS revealed that JS-R plants had faster metabolic rates to metamifop than YN-S plants. Meanwhile, the JS-R popultion exhibited resistant to cyhalofop-butyl and penoxsulam. In summary, this study presented a novel discovery regarding the global emergence of metabolic resistance to metamifop in E. crus-galli. The low-level resistance observed in the JS-R population was not found to be related to TSR but rather appeared to be primarily associated with the overexpression of genes in the GSTs metabolic enzyme superfamily.
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Affiliation(s)
- Penglei Sun
- Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Liangliang Niu
- Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Xianmin Lan
- Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China; Institute of Plant Protection, Guizhou Academy of Agricultural Science, Guiyang 550006, China
| | - Haiyan Yu
- Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Hailan Cui
- Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Jingchao Chen
- Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Xiangju Li
- Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China.
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Brunharo CACG, Tranel PJ. Repeated evolution of herbicide resistance in Lolium multiflorum revealed by haplotype-resolved analysis of acetyl-CoA carboxylase. Evol Appl 2023; 16:1969-1981. [PMID: 38143902 PMCID: PMC10739073 DOI: 10.1111/eva.13615] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2023] [Revised: 06/27/2023] [Accepted: 10/24/2023] [Indexed: 12/26/2023] Open
Abstract
Herbicide resistance in weeds is one of the greatest challenges in modern food production. The grass species Lolium multiflorum is an excellent model species to investigate evolution under similar selection pressure because populations have repeatedly evolved resistance to many herbicides, utilizing a multitude of mechanisms to neutralize herbicide damage. In this work, we investigated the gene that encodes acetyl-CoA carboxylase (ACCase), the target site of the most successful herbicide group available for grass weed control. We sampled L. multiflorum populations from agricultural fields with history of intense herbicide use, and studied their response to three ACCase-inhibiting herbicides. To elucidate the mechanisms of herbicide resistance and the genetic relationship among populations, we resolved the haplotypes of 97 resistant and susceptible individuals by sequencing ACCase amplicons using long-read DNA sequencing technologies. Our dose-response data indicated the existence of many, often unpredictable, resistance patterns to ACCase-inhibiting herbicides, where populations exhibited as much as 37-fold reduction in herbicide response. The majority of the populations exhibited resistance to all three herbicides studied. Phylogenetic and molecular genetic analyses revealed multiple evolutionary origins of resistance-endowing ACCase haplotypes, as well as widespread admixture in the region regardless of cropping system. The amplicons generated were diverse, with haplotypes exhibiting 26-110 polymorphisms. Polymorphisms included insertions and deletions 1-31 bp in length, none of which were associated with the resistance phenotype based on an association analysis. We also found evidence that some populations have multiple mechanisms of resistance. Our results highlight the astounding genetic diversity in L. multiflorum populations, and the potential for repeated evolution of herbicide resistance across the landscape that challenges weed management approaches and jeopardizes sustainable weed control practices. We provide an in-depth discussion of the evolutionary and practical implications of our results.
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Affiliation(s)
- Caio A. C. G. Brunharo
- Department of Plant ScienceThe Pennsylvania State UniversityUniversity ParkPennsylvaniaUSA
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Guan T, Zhang Y, Zhu Q, Wang L, Feng J, Wang H, Li J. Effects of Metamifop on Defense Systems in Monopterus albus. TOXICS 2023; 11:811. [PMID: 37888662 PMCID: PMC10611219 DOI: 10.3390/toxics11100811] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2023] [Revised: 09/19/2023] [Accepted: 09/22/2023] [Indexed: 10/28/2023]
Abstract
The effects of herbicides on non-target organisms in paddy fields have become a popular research topic. As a widely used herbicide, it is necessary to explore the potential toxicity of metamifop in non-target organisms, especially aquatic animals, in co-culture mode. In the present study, we evaluated the effects of metamifop (0, 0.2, 0.4, 0.6, and 0.8 mg/L) on the defense system (antioxidation, immunity, and apoptosis) in Monopterus albus. Reactive oxygen species (ROS) production, malondialdehyde (MDA) content, and protein carbonylation (PCO) increased significantly (p < 0.05) with the increasing metamifop concentration, resulting in oxidative damage. In the antioxidant system, superoxide dismutase (SOD) and catalase (CAT) activities increased significantly (p < 0.05) in the 0.2 mg/L treatment group compared with the control group, and decreased in 0.4, 0.6, and 0.8 mg/L treatment groups. Glutathione peroxidase (GPX) activity decreased significantly (p < 0.05) with the increasing metamifop concentration. In the immune system, white cell number (WCN) increased significantly (p < 0.05) in 0.2 mg/L treatment group, and then decreased with the increase in metamifop concentration. Compared with control group, acid phosphatase (ACP) activity not only increased significantly (p < 0.05) in 0.2 mg/L treatment group, but also decreased significantly (p < 0.05) compared with the increase in metamifop concentration. However, in all treatment groups, alkaline phosphatase (AKP) activity was significantly lower than that in the control group (p < 0.05). In the inflammatory response, TNF-α and IL-1β expression levels in the NF-κB signaling pathway decreased significantly (p < 0.05) with the increase in metamifop concentration, while IL-8 expression level in the same signaling pathway increased significantly (p < 0.05) in treatment groups. The expression levels of genes related to apoptosis showed that apoptosis was promoted after exposure to metamifop. The results of the present study show that metamifop induced oxidative damage via a high level of ROS production, and then inhibited or damaged the defense systems of M. albus.
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Affiliation(s)
- Tianyu Guan
- Jiangsu Collaborative Innovation Center of Regional Modern Agriculture & Environmental Protection, Huaiyin Normal University, Huai’an 223300, China; (T.G.)
- Key Laboratory of Freshwater Aquatic Genetic Resources, Ministry of Agriculture, Shanghai Ocean University, Shanghai 201306, China
| | - Yi Zhang
- School of Oceanography, Ningbo University, Ningbo 315211, China
| | - Qianqian Zhu
- Jiangsu Collaborative Innovation Center of Regional Modern Agriculture & Environmental Protection, Huaiyin Normal University, Huai’an 223300, China; (T.G.)
| | - Long Wang
- Jiangsu Collaborative Innovation Center of Regional Modern Agriculture & Environmental Protection, Huaiyin Normal University, Huai’an 223300, China; (T.G.)
- Key Laboratory of Freshwater Aquatic Genetic Resources, Ministry of Agriculture, Shanghai Ocean University, Shanghai 201306, China
| | - Jianbin Feng
- Key Laboratory of Freshwater Aquatic Genetic Resources, Ministry of Agriculture, Shanghai Ocean University, Shanghai 201306, China
- National Demonstration Center for Experimental Fisheries Science Education, Shanghai Ocean University, Shanghai 201306, China
| | - Hui Wang
- Jiangsu Collaborative Innovation Center of Regional Modern Agriculture & Environmental Protection, Huaiyin Normal University, Huai’an 223300, China; (T.G.)
| | - Jiale Li
- Key Laboratory of Freshwater Aquatic Genetic Resources, Ministry of Agriculture, Shanghai Ocean University, Shanghai 201306, China
- National Demonstration Center for Experimental Fisheries Science Education, Shanghai Ocean University, Shanghai 201306, China
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Cao J, Tao Y, Zhang Z, Gu T, Li G, Lou Y, Wang H. Mechanism of metamifop resistance in Digitaria ciliaris var. chrysoblephara from Jiangsu, China. FRONTIERS IN PLANT SCIENCE 2023; 14:1133798. [PMID: 36895875 PMCID: PMC9989310 DOI: 10.3389/fpls.2023.1133798] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Accepted: 01/30/2023] [Indexed: 06/18/2023]
Abstract
Digitaria ciliaris var. chrysoblephara is one of the most competitive and problematic grass weeds in China. Metamifop is an aryloxyphenoxypropionate (APP) herbicide that inhibits the activity of acetyl-CoA carboxylase (ACCase) of sensitive weeds. Following the introduction of metamifop to China in 2010, it has been continuously used in rice paddy fields, thereby substantially increasing selective pressure for resistant D. ciliaris var. chrysoblephara variants. Here, populations of D. ciliaris var. chrysoblephara (JYX-8, JTX-98, and JTX-99) were observed to be highly resistant to metamifop, with resistance index (RI) values of 30.64, 14.38, and 23.19, respectively. Comparison of resistant and sensitive population ACCase gene sequences revealed that a single nucleotide substitution from TGG to TGC resulted in an amino acid substitution from tryptophan to cysteine at position 2,027 in the JYX-8 population. No corresponding substitution was observed for JTX-98 and JTX-99 populations. The ACCase cDNA of D. ciliaris var. chrysoblephara was successfully obtained by PCR and RACE methods, representing the first amplification of full length ACCase cDNA from Digitaria spp. Investigation of the relative expressions of ACCase gene revealed the lack of significant differences between sensitive and resistant populations before and after herbicide treatments. ACCase activities in resistant populations were less inhibited than in sensitive populations and recovered to the same or even higher levels compared to untreated plants. Whole-plant bioassays were also conducted to assess resistance to other ACCase inhibitors, acetolactate synthase (ALS) inhibitors, auxin mimic herbicide, and protoporphyrinogen oxidase (PPO) inhibitor. Cross-resistance and some multi-resistance were observed in the metamifop-resistant populations. This study is the first to focus on the herbicide resistance of D. ciliaris var. chrysoblephara. These results provide evidence for a target-site resistance mechanism in metamifop-resistant D. ciliaris var. chrysoblephara, while providing a better understanding of cross- and multi-resistance characteristics of resistant populations that will help in the management of herbicide-resistant D. ciliaris var. chrysoblephara.
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Zhang Y, Guan T, Wang L, Ma X, Zhu C, Wang H, Li J. Metamifop as an estrogen-like chemical affects the pituitary-hypothalamic-gonadal (HPG) axis of female rice field eels ( Monopterus albus). Front Physiol 2023; 14:1088880. [PMID: 36744025 PMCID: PMC9892845 DOI: 10.3389/fphys.2023.1088880] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2022] [Accepted: 01/09/2023] [Indexed: 01/21/2023] Open
Abstract
Metamifop (MET) is a widely used herbicide. It is likely for it to enter water environment when utilized, thus potential impacts may be produced on aquatic animals. Little information is available about its effects on the endocrine system of fish to date. In the current study, female rice field eels (Monopterus albus) were exposed to different MET concentrations (0, 0.2, 0.4, 0.6, 0.8 mg L -1) for 96 h to examine the effect of MET on the hypothalamic-pituitary-gonadal (HPG) axis and sexual reversal. The results showed that high concentrations of MET exposure increased vitellogenin (VTG) levels in liver and plasma, but plasma sex hormone levels were not affected by MET exposure. MET exposure increased the expression of CYP19A1b and CYP17 that regulate sex hormone production in the brain, but the expression of genes (CYP19A1a, CYP17, FSHR, LHCGR, hsd11b2, 3β-HSD) associated with sex hormone secretion in the ovary and the estrogen receptor genes (esr1, esr2a, esr2b) in the liver were all suppressed. In addition, the expression of sex-related gene (Dmrt1) was suppressed. This study revealed for the first time that MET has estrogen-like effects and has a strong interference with the expression of HPG axis genes. MET did not show the ability to promote the sexual reversal in M. albus, on the contrary, the genes expression showed that the occurrence of male pathway was inhibited.
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Affiliation(s)
- Yi Zhang
- School of Life Science, Huaiyin Normal University, Huai’an, China,Key Laboratory of Freshwater Aquatic Genetic Resources Ministry of Agriculture, Shanghai Ocean University, Shanghai, China
| | - Tianyu Guan
- School of Life Science, Huaiyin Normal University, Huai’an, China,Key Laboratory of Freshwater Aquatic Genetic Resources Ministry of Agriculture, Shanghai Ocean University, Shanghai, China
| | - Long Wang
- School of Life Science, Huaiyin Normal University, Huai’an, China,Key Laboratory of Freshwater Aquatic Genetic Resources Ministry of Agriculture, Shanghai Ocean University, Shanghai, China
| | - Xintong Ma
- School of Life Science, Huaiyin Normal University, Huai’an, China
| | - Chuankun Zhu
- School of Life Science, Huaiyin Normal University, Huai’an, China
| | - Hui Wang
- School of Life Science, Huaiyin Normal University, Huai’an, China,*Correspondence: Hui Wang,
| | - Jiale Li
- Key Laboratory of Freshwater Aquatic Genetic Resources Ministry of Agriculture, Shanghai Ocean University, Shanghai, China
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Zhao F, Guo M, Zhang M, Duan M, Zheng J, Liu Y, Qiu L. Sub-lethal concentration of metamifop exposure impair gut health of zebrafish (Danio rerio). CHEMOSPHERE 2022; 303:135081. [PMID: 35636611 DOI: 10.1016/j.chemosphere.2022.135081] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2022] [Revised: 04/25/2022] [Accepted: 05/20/2022] [Indexed: 06/15/2023]
Abstract
Previous studies have demonstrated that sublethal metamifop exposures induce hepatic lipid metabolism disorder in zebrafish. Whether metamifop will cause adverse effects in zebrafish gut is unknown. In the present study, effects of metamifop on gut heath of zebrafish were investigated after sublethal concentration (0.025, 0.10 and 0.40 mg/L) exposure. Histopathology analysis showed that metamifop induced inflammation and reduction of goblet cells in the gut, indicating that gut health may be impaired. Metamifop exposure could reduce activities of digestive enzymes (lipase and alkaline phosphatase), indicating the capacity of lipid absorption were impaired. Meanwhile, the content of fatty acid-binding protein 2 (FABP2) and mRNA levels of related genes (apoa-1a, apoe-b, fatp4, lpl and fabp2) were reduced in zebrafish gut after exposure to metamifop, suggesting the lipid transportation were decreased. The transcripts of genes associated with inflammation (il-17c, tnf-α and nf-kb) were significantly increased in 0.40 mg/L metamifop treatment group, which were 1.90-, 1.53- and 2.77-fold of the control group, respectively, confirming that metamifop induced inflammatory response in zebrafish gut. Moreover, reduction of mRNA levels of cldn-15 and elevation of lipopolysaccharides (LPS) content were observed in metamifop-treated groups, which suggested that metamifop exposure increased the intestinal permeability. Furthermore, metamifop exposure decreased the relative abundance of beneficial bacteria (Psychrobacter and Aeromonas) and elevated the abundance of pathogenic bacteria (Rhodobacter and Ralstonia) in zebrafish intestine. These results indicated that metamifop exposure at sublethal concentrations would impair zebrafish gut health, via reduction of lipids absorption, inflammatory response, elevation of permeability and microbiota disorder.
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Affiliation(s)
- Feng Zhao
- Innovation Center of Pesticide Research, Department of Applied Chemistry, College of Science, China Agricultural University, Beijing, 100193, China
| | - Mengyu Guo
- Innovation Center of Pesticide Research, Department of Applied Chemistry, College of Science, China Agricultural University, Beijing, 100193, China
| | - Mengna Zhang
- Innovation Center of Pesticide Research, Department of Applied Chemistry, College of Science, China Agricultural University, Beijing, 100193, China
| | - Manman Duan
- Innovation Center of Pesticide Research, Department of Applied Chemistry, College of Science, China Agricultural University, Beijing, 100193, China
| | - Junyue Zheng
- Innovation Center of Pesticide Research, Department of Applied Chemistry, College of Science, China Agricultural University, Beijing, 100193, China
| | - Yinchi Liu
- Innovation Center of Pesticide Research, Department of Applied Chemistry, College of Science, China Agricultural University, Beijing, 100193, China
| | - Lihong Qiu
- Innovation Center of Pesticide Research, Department of Applied Chemistry, College of Science, China Agricultural University, Beijing, 100193, China.
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Tyagi S, McKillican BP, Salvador TK, Gichinga MG, Eberle WJ, Viner R, Makaravage KJ, Johnson TS, Russell CA, Roy S. Bioinspired Synthesis of Pinoxaden Metabolites Using a Site-Selective C-H Oxidation Strategy. J Org Chem 2022; 87:6202-6211. [PMID: 35442682 DOI: 10.1021/acs.joc.2c00440] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A bioinspired synthesis of Pinoxaden metabolites 2-5 is described herein. A site-selective C-H oxidation strategy validated by density functional theory (DFT) calculations was devised for preparing metabolites 2-4. Oxidation of the benzylic C-H bond in tertiary alcohol 7 using K2S2O8 and catalytic AgNO3 formed the desired metabolite 2 that enabled access to metabolites 3 and 4 in a single step. Unlike most metal/persulfate-catalyzed transformations reported for the C-C and C-O bond formation reactions wherein the metal acts as a catalyst, we propose that Ag(I)/K2S2O8 plays the role of an initiator in the oxidation of intermediate 7 to 2. Metabolite 2 was subjected to a ruthenium tetroxide-mediated C-H oxidation to form metabolites 3 and 4 as a mixture that were purified to isolate pure standards of these metabolites. Metabolite 5 was synthesized from readily available advanced intermediate 9 via a House-Meinwald-type rearrangement in one step using a base.
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Affiliation(s)
- Sameer Tyagi
- Product Metabolism Analytical Sciences, Syngenta Group, 410 Swing Road, Greensboro, North Carolina 27409, United States
| | - Bruce P McKillican
- Product Metabolism Analytical Sciences, Syngenta Group, 410 Swing Road, Greensboro, North Carolina 27409, United States
| | - Tolani K Salvador
- Product Metabolism Analytical Sciences, Syngenta Group, 410 Swing Road, Greensboro, North Carolina 27409, United States
| | - Moses G Gichinga
- Product Metabolism Analytical Sciences, Syngenta Group, 410 Swing Road, Greensboro, North Carolina 27409, United States
| | - William J Eberle
- Product Metabolism Analytical Sciences, Syngenta Group, 410 Swing Road, Greensboro, North Carolina 27409, United States
| | - Russell Viner
- Research Chemistry, Syngenta Group, Jealott's Hill International Research Center, Bracknell, Berkshire RG 42 6EY, United Kingdom
| | - Katarina J Makaravage
- Product Metabolism Analytical Sciences, Syngenta Group, 410 Swing Road, Greensboro, North Carolina 27409, United States
| | - Trey S Johnson
- Product Metabolism Analytical Sciences, Syngenta Group, 410 Swing Road, Greensboro, North Carolina 27409, United States
| | - C Adam Russell
- Product Metabolism Analytical Sciences, Syngenta Group, Jealott's Hill International Research Center, Bracknell, Berkshire RG 42 6EY, United Kingdom
| | - Subho Roy
- TCG Lifesciences, Chembiotek, Block BN, Plot 7, Salt Lake Electronics Complex, Sector V, Kolkata 700091, West Bengal, India
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Pan L, Guo Q, Wang J, Shi L, Yang X, Zhou Y, Yu Q, Bai L. CYP81A68 confers metabolic resistance to ALS and ACCase-inhibiting herbicides and its epigenetic regulation in Echinochloa crus-galli. JOURNAL OF HAZARDOUS MATERIALS 2022; 428:128225. [PMID: 35032953 DOI: 10.1016/j.jhazmat.2022.128225] [Citation(s) in RCA: 38] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2021] [Revised: 12/23/2021] [Accepted: 01/04/2022] [Indexed: 06/14/2023]
Abstract
Long-term and excessive herbicide use has led to some environmental concerns and especially, herbicide resistance evolution in weeds. Here, we confirmed acetolactate synthase (ALS) inhibiting herbicide penoxsulam resistance and cross resistance to acetyl-coenzyme carboxylase (ACCase) inhibiting herbicides (cyhalofop-butyl and metamifop) in a global weed Echinochloa crus-galli population resistant to these herbicides (R). Penoxsulam metabolism study indicated that degradation rate was significantly higher in R than susceptible E. crus-galli population (S). RNA-sequencing revealed that a cytochrome P450 (P450) gene, CYP81A68, expressed higher in R versus S. Rice seedlings overexpressing this CYP81A68 gene are resistant to penoxsulam, cyhalofop-butyl and metamifop, and penoxsulam resistance is due to enhanced metabolism via O-demethylation. Deletion analysis of the CYP81A68 gene promoter identified an efficient region, in which differential methylation of CpG islands occurred between R and S. Collectively, these results demonstrate that upregulation of E. crus-galli CYP81A68 gene endows generalist metabolic resistance to commonly used ALS- and ACCase-inhibiting herbicides in rice fields and epigenetic regulation may play a role in the resistance evolution. This research could contribute to strategies reducing herbicide environmental impacts by judicious selection of alternative herbicide and non-chemical control tactics.
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Affiliation(s)
- Lang Pan
- College of Plant Protection, Hunan Agricultural University, Changsha 410128, China
| | - Qiushuang Guo
- College of Plant Protection, Hunan Agricultural University, Changsha 410128, China
| | - Junzhi Wang
- College of Plant Protection, Hunan Agricultural University, Changsha 410128, China
| | - Li Shi
- College of Plant Protection, Hunan Agricultural University, Changsha 410128, China
| | - Xiao Yang
- Key Laboratory of Land Surface Pattern and Simulation, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China
| | - Yaoyu Zhou
- College of Resources and Environment, Hunan Agricultural University, Changsha 410128, China.
| | - Qin Yu
- Australian Herbicide Resistance Initiative (AHRI), School of Agriculture and Environment, University of Western Australia, Crawley, WA 6009, Australia.
| | - Lianyang Bai
- College of Plant Protection, Hunan Agricultural University, Changsha 410128, China.
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11
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Liu R, Qin Y, Diao J, Zhang H. Xenopus laevis tadpoles exposed to metamifop: Changes in growth, behavioral endpoints, neurotransmitters, antioxidant system and thyroid development. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2021; 220:112417. [PMID: 34126306 DOI: 10.1016/j.ecoenv.2021.112417] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Revised: 06/03/2021] [Accepted: 06/08/2021] [Indexed: 06/12/2023]
Abstract
Pesticides are a major cause of the reduction in the global amphibian population. In this study, the acute toxicity and chronic effects of metamifop on Xenopus laevis (X. laevis) tadpoles were investigated. The 96 h-LC50 value of metamifop on X. laevis tadpoles was 0.634 mg/L, which indicated that metamifop was highly toxic to tadpoles. In the chronic toxicity study, tadpoles were exposed to 0.063 mg/L of metamifop. After 14, 21 and 35 d of exposure, metamifop significantly inhibited the body weight and neurotransmitter synthesis of tadpoles, caused abnormal behavior and interfered with fat metabolism. According to the results of antioxidant enzymes and malondialdehyde (MDA), tadpoles exposed to 0.063 mg/L metamifop suffered severe lipid oxidative damage. Compared with the control group, the thyroid hormone (TH) levels and related gene expression in tadpoles in the treatment group were affected, reflecting the endocrine interference effect of metamifop. The data of this study can enrich our knowledge of the effects of aryloxyphenoxy propionate pesticides on amphibians and highlight the role of metamifop and other pesticides play in global decline of amphibians.
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Affiliation(s)
- Rui Liu
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, Department of Applied Chemistry, China Agricultural University, No. 2 West Yuanmingyuan Road, Beijing 100193, PR China
| | - Yinan Qin
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, Department of Applied Chemistry, China Agricultural University, No. 2 West Yuanmingyuan Road, Beijing 100193, PR China
| | - Jinling Diao
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, Department of Applied Chemistry, China Agricultural University, No. 2 West Yuanmingyuan Road, Beijing 100193, PR China
| | - Hongjun Zhang
- Institute for the Control of Agrochemicals, Ministry of Agriculture and Rural Affairs (ICAMA), No. 22 Maizidian Street, Chaoyang, Beijing 100125, PR China.
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12
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Zhao F, Zhang M, Guo M, Duan M, Zheng J, Chen X, Liu Y, Qiu L. Effects of sublethal concentration of metamifop on hepatic lipid metabolism in adult zebrafish (Danio rerio). AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2021; 238:105938. [PMID: 34416465 DOI: 10.1016/j.aquatox.2021.105938] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Revised: 07/22/2021] [Accepted: 08/09/2021] [Indexed: 06/13/2023]
Abstract
Metamifop (MET) is an effective herbicide that has been extensively used in paddy fields. Previous research demonstrated that MET was highly toxic to zebrafish embryos, and this threat has caused great concern; moreover, 0.40 mg/L MET elevated the hepatosomatic index (HSI) in adult zebrafish without lethal effect after 21 d of exposure. In this study, we further determined the detailed impacts of MET on adult zebrafish at sublethal concentrations (0.025, 0.10 and 0.40 mg/L). We found that 0.40 mg/L MET caused liver injury by increasing the activity of aspartate aminotransferase and alanine aminotransferase in plasma, the content of interleukin-1β, IL-6, tumor necrosis factor-α, and mRNA expression level of genes associated with inflammatory response in liver of adult zebrafish. The hepatic triglyceride (TG), free fatty acid and fatty acid synthase levels were significantly elevated in 0.40 mg/L MET-treated group (1.55-, 2.20- and 2.30-fold, respectively), and the transcript of lipid accumulation-related genes (fabp10, fas, acc, chrebp, dagt2 and agpat4) were upregulated. Meanwhile, the total cholesterol content was decreased by 0.48-fold, bile acid level was increased by 2.44-fold, and levels of cholesterol metabolism-related genes (apoa-1a, hmgcra, cyp51, dhcr7 and cyp7a1) were increased, suggesting cholesterol metabolism disorder occurred in zebrafish. Furthermore, analysis of lipidomics revealed that 0.40 mg/L MET significantly increased the abundance of 91 lipids, which mainly belonged to TG lipid class and were enriched in pathways of glycerolipid metabolism, cholesterol metabolism, etc. These results suggested that MET exposure at sublethal concentrations would induce hepatic inflammation and lipid metabolism disorders in adult zebrafish.
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Affiliation(s)
- Feng Zhao
- Innovation Center of Pesticide Research, Department of Applied Chemistry, College of Science, China Agricultural University, Beijing 100193, China
| | - Mengna Zhang
- Innovation Center of Pesticide Research, Department of Applied Chemistry, College of Science, China Agricultural University, Beijing 100193, China
| | - Mengyu Guo
- Innovation Center of Pesticide Research, Department of Applied Chemistry, College of Science, China Agricultural University, Beijing 100193, China
| | - Manman Duan
- Innovation Center of Pesticide Research, Department of Applied Chemistry, College of Science, China Agricultural University, Beijing 100193, China
| | - Junyue Zheng
- Innovation Center of Pesticide Research, Department of Applied Chemistry, College of Science, China Agricultural University, Beijing 100193, China
| | - Xiangguang Chen
- Innovation Center of Pesticide Research, Department of Applied Chemistry, College of Science, China Agricultural University, Beijing 100193, China
| | - Yinchi Liu
- Innovation Center of Pesticide Research, Department of Applied Chemistry, College of Science, China Agricultural University, Beijing 100193, China
| | - Lihong Qiu
- Innovation Center of Pesticide Research, Department of Applied Chemistry, College of Science, China Agricultural University, Beijing 100193, China.
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13
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Lin J, Li Y, Hu X, Chi W, Zeng S, Xu J. Discovery of novel 3‐{[(5,5‐dimethyl‐4,5‐dihydroisoxazol‐3‐yl)sulfonyl]methyl}benzo[d]isoxazole analogs as promising very long chain fatty acids inhibitors. J Heterocycl Chem 2020. [DOI: 10.1002/jhet.4162] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Jian Lin
- Dongguan HEC Pesticides R&D Co., Ltd. Dongguan China
- College of Chemistry Biology and Environmental Engineering Xiangnan University Chenzhou China
| | - Yitao Li
- Dongguan HEC Pesticides R&D Co., Ltd. Dongguan China
| | - Xiaoyun Hu
- Dongguan HEC Pesticides R&D Co., Ltd. Dongguan China
| | - Weilin Chi
- Dongguan HEC Pesticides R&D Co., Ltd. Dongguan China
| | - Shuiming Zeng
- Dongguan HEC Pesticides R&D Co., Ltd. Dongguan China
| | - Junxing Xu
- Dongguan HEC Pesticides R&D Co., Ltd. Dongguan China
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14
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Harnessing the Power of Mutagenesis and Adaptive Laboratory Evolution for High Lipid Production by Oleaginous Microalgae and Yeasts. SUSTAINABILITY 2020. [DOI: 10.3390/su12125125] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Oleaginous microalgae and yeasts represent promising candidates for large-scale production of lipids, which can be utilized for production of drop-in biofuels, nutraceuticals, pigments, and cosmetics. However, low lipid productivity and costly downstream processing continue to hamper the commercial deployment of oleaginous microorganisms. Strain improvement can play an essential role in the development of such industrial microorganisms by increasing lipid production and hence reducing production costs. The main means of strain improvement are random mutagenesis, adaptive laboratory evolution (ALE), and rational genetic engineering. Among these, random mutagenesis and ALE are straight forward, low-cost, and do not require thorough knowledge of the microorganism’s genetic composition. This paper reviews available mutagenesis and ALE techniques and screening methods to effectively select for oleaginous microalgae and yeasts with enhanced lipid yield and understand the alterations caused to metabolic pathways, which could subsequently serve as the basis for further targeted genetic engineering.
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15
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Yao L, Ma H, Nie Z, Nie H, Zhang D, Wei Z, Shen Z, Chen W, Jiang R, Zhang S. A practical strategy to access chiral α-aryloxy carboxylic acids through ion-pairing directed asymmetric hydrogenation. Org Chem Front 2020. [DOI: 10.1039/d0qo01205j] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A series of optically active α-aryloxy functionalized carboxylic acids were obtained via non-covalent interaction assisted highly efficient asymmetric hydrogenation.
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16
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Zhao F, Li H, Cao F, Chen X, Liang Y, Qiu L. Short-term developmental toxicity and potential mechanisms of the herbicide metamifop to zebrafish (Danio rerio) embryos. CHEMOSPHERE 2019; 236:124590. [PMID: 31470984 DOI: 10.1016/j.chemosphere.2019.124590] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Revised: 08/07/2019] [Accepted: 08/13/2019] [Indexed: 06/10/2023]
Abstract
Metamifop is a novel aryloxyphenoxy propionate (AOPP) herbicide that is widely applied in paddy fields, which will inevitably enter aquatic environments and pose a risk to aquatic organisms. However, the potential threat and toxicological mechanisms of metamifop in aquatic organisms are poorly understood. In this study, zebrafish embryos were used to investigate the potential developmental toxicity and mechanisms of metamifop. The results showed that metamifop exhibited high acute toxicity to zebrafish, with 96 h-LC50 values of 0.648 and 0.216 mg/L to embryos and larvae of 72 h post-hatching (hph), respectively. Decreased body lengths, heartbeat number, and hatching rates, and increased malformation rates of embryos were observed after 96 h of exposure to 0.38 mg/L or higher concentration of metamifop. Furthermore, oxidative stress was caused in embryos, with increased contents of reactive oxygen species (ROS) and malondialdehyde (MDA), and altered activities of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx). Metamifop exposure clearly triggered cell apoptosis in embryos, result in the increase of Caspase-3 and Caspase-9 activities and up-regulation of apoptosis-related genes (bax, p53, apaf1, caspase-3, and caspase-9). Additionally, the transcriptions of innate immune-related genes (il-8, il-1b, and ifn) were increased in the groups treated with 0.25 and 0.5 mg/L of metamifop. These results indicate that metamifop induced developmental toxicity in zebrafish, and the potential toxicological mechanisms were related to oxidative stress, cell apoptosis, and the innate immune responses in embryos.
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Affiliation(s)
- Feng Zhao
- Department of Applied Chemistry, College of Science, China Agricultural University, Beijing, 100193, China
| | - Hui Li
- Department of Applied Chemistry, College of Science, China Agricultural University, Beijing, 100193, China
| | - Fangjie Cao
- Department of Applied Chemistry, College of Science, China Agricultural University, Beijing, 100193, China
| | - Xiangguang Chen
- Department of Applied Chemistry, College of Science, China Agricultural University, Beijing, 100193, China
| | - Yong Liang
- Department of Applied Chemistry, College of Science, China Agricultural University, Beijing, 100193, China
| | - Lihong Qiu
- Department of Applied Chemistry, College of Science, China Agricultural University, Beijing, 100193, China.
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17
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Ding F, Li LX, Peng W, Peng YK, Liu BQ. Molecular basis for the resistance of American sloughgrass to aryloxyphenoxypropionic acid pesticides and its environmental relevance: A combined experimental and computational study. CHEMOSPHERE 2019; 235:1030-1040. [PMID: 31561292 DOI: 10.1016/j.chemosphere.2019.07.044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Revised: 07/04/2019] [Accepted: 07/05/2019] [Indexed: 06/10/2023]
Abstract
Organic pesticides are one of the main environmental pollutants, and how to reduce their environmental risks is an important issue. In this contribution, we disclose the molecular basis for the resistance of American sloughgrass to aryloxyphenoxypropionic acid pesticides using site-directed mutagenesis and molecular modeling and then construct an effective screening model. The results indicated that the target-site mutation (Trp-1999-Leu) in acetyl-coenzyme A carboxylase (ACCase) can affect the effectiveness of the pesticides (clodinafop, fenoxaprop, cyhalofop, and metamifop), and the plant resistance to fenoxaprop, clodinafop, cyhalofop, and metamifop was found to be 564, 19.5, 10, and 0.19 times, respectively. The established computational models (i.e. wild-type/mutant ACCase models) could be used for rational screening and evaluation of the resistance to pesticides. The resistance induced by target gene mutation can markedly reduce the bioreactivity of the ACCase-clodinafop/fenoxaprop adducts, and the magnitudes are 10 and 102, respectively. Such event will seriously aggravate environmental pollution. However, the biological issue has no distinct effect on cyhalofop (RI=10), and meanwhile it may markedly increase the bioefficacy of metamifop (RI=0.19). We could selectively adopt the two chemicals so as to decrease the residual pesticides in the environment. Significantly, research findings from the computational screening models were found to be negatively correlated with the resistance level derived from the bioassay testing, suggesting that the screening models can be used to guide the usage of pesticides. Obviously, this story may shed novel insight on the reduction of environmental risks of pesticides and other organic pollutants.
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Affiliation(s)
- Fei Ding
- School of Environmental Science and Engineering, Chang'an University, Xi'an, 710064, China; Key Laboratory of Subsurface Hydrology and Ecological Effect in Arid Region of Ministry of Education, Chang'an University, No. 126 Yanta Road, Yanta District, Xi'an, 710064, China
| | - Ling-Xu Li
- Department of Agricultural Chemistry, Qingdao Agricultural University, Qingdao, 266109, China
| | - Wei Peng
- College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, China; Department of Chemistry, China Agricultural University, Beijing, 100193, China.
| | - Yu-Kui Peng
- Center for Food Quality Supervision, Inspection & Testing, Ministry of Agriculture, Northwest A&F University, Yangling, 712100, China
| | - Bing-Qi Liu
- Department of Agricultural Chemistry, Qingdao Agricultural University, Qingdao, 266109, China
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18
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Affiliation(s)
- Kuntal Chatterjee
- Institut für Optik und Atomare Physik, TU Berlin, Hardenbergstr. 36, 10623 Berlin, Germany
| | - Otto Dopfer
- Institut für Optik und Atomare Physik, TU Berlin, Hardenbergstr. 36, 10623 Berlin, Germany
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Chatterjee K, Dopfer O. Unraveling the protonation site of oxazole and solvation with hydrophobic ligands by infrared photodissociation spectroscopy. Phys Chem Chem Phys 2019; 21:15157-15166. [DOI: 10.1039/c9cp02787d] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Infrared spectroscopy reveals exclusive N-protonation of the oxazole ring and bifurcated or linear hydrogen bonding with hydrophobic N2and Ar ligands.
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Affiliation(s)
| | - Otto Dopfer
- Institut für Optik und Atomare Physik
- TU Berlin
- 10623 Berlin
- Germany
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20
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Barik SR, Ganguly P, Patra S, Dutta SK, Goon A, Bhattacharyya A. Persistence behavior of metamifop and its metabolite in rice ecosystem. CHEMOSPHERE 2018; 193:875-882. [PMID: 29874762 DOI: 10.1016/j.chemosphere.2017.11.101] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2017] [Revised: 11/17/2017] [Accepted: 11/19/2017] [Indexed: 06/08/2023]
Abstract
A field experiment was conducted to determine the persistence of metamifop in transplanted rice crop for two seasons. Metamifop 10% EC was applied at two doses: 100 g a.i. ha-1 and 200 g a.i. ha-1 at 2-3 leaf stage of Echinochloa crusgalli. The residues of metamifop along with its major metabolite, N-(2-fluorophenyl)-2-hydroxy-N-methylpropionamide (HFMPA), were estimated in rice plant, field water and soil using Liquid Chromatography Mass Spectrometry. Limit of detection and limit of quantification of the method for both the compounds were set at 0.003 μg g-1 and 0.010 μg g-1 respectively. Metamifop showed less persistence in field water and rice plant as compared to soil samples. Presence of HFMPA was recorded in rice plant and soil. Both the compounds were found below level of quantification in harvest samples of straw, grains, husk and soil. A safe waiting period of 52 d was suggested for harvesting of rice when metamifop was applied at 100 g a.i. ha-1 (recommended dose).
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Affiliation(s)
- Suhrid Ranjan Barik
- Department of Agricultural Chemicals, Bidhan Chandra Krishi Viswavidyalaya, Mohanpur, Nadia, West Bengal, India
| | - Pritam Ganguly
- Department of Soil Science & Agricultural Chemistry, Bihar Agricultural University, Sabour, Bhagalpur, Bihar, India
| | - Sandip Patra
- Division of Crop Protection, ICAR Research Complex for NEH Region, Shillong, Meghalaya, India.
| | - Swaraj Kumar Dutta
- Department of Agronomy, Bihar Agricultural University, Sabour, Bhagalpur, Bihar, India
| | - Arnab Goon
- Department of Agricultural Chemicals, Bidhan Chandra Krishi Viswavidyalaya, Mohanpur, Nadia, West Bengal, India
| | - Anjan Bhattacharyya
- Department of Agricultural Chemicals, Bidhan Chandra Krishi Viswavidyalaya, Mohanpur, Nadia, West Bengal, India
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21
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Brown AW. Recent Developments in the Chemistry of Pyrazoles. ADVANCES IN HETEROCYCLIC CHEMISTRY 2018. [DOI: 10.1016/bs.aihch.2018.02.001] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
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