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Andrä J, Aisenbrey C, Sudheendra US, Prudhon M, Brezesinski G, Zschech C, Willumeit-Römer R, Leippe M, Gutsmann T, Bechinger B. Structural analysis of the NK-lysin-derived peptide NK-2 upon interaction with bacterial membrane mimetics consisting of phosphatidylethanolamine and phosphatidylglycerol. Biochim Biophys Acta Biomembr 2024; 1866:184267. [PMID: 38159877 DOI: 10.1016/j.bbamem.2023.184267] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2023] [Revised: 12/19/2023] [Accepted: 12/20/2023] [Indexed: 01/03/2024]
Abstract
NK-2 is an antimicrobial peptide derived from helices 3 and 4 of the pore-forming protein of natural killer cells, NK-lysin. It has potent activities against Gram-negative and Gram-positive bacteria, fungi and protozoan parasites without being toxic to healthy human cells. In biophysical assays its membrane activities were found to require phosphatidylglycerol (PG) and phosphatidylethanolamine (PE), lipids which dominate the composition of bacterial membranes. Here the structure and activities of NK-2 in binary mixtures of different PE/PG composition were investigated. CD spectroscopy reveals that a threshold concentration of 50 % PG is needed for efficient membrane association of NK-2 concomitant with a random coil - helix transition. Association with PE occurs but is qualitatively different when compared to PG membranes. Oriented solid-state NMR spectroscopy of NK-2 specifically labelled with 15N indicates that the NK-2 helices are oriented parallel to the PG bilayer surface. Upon reduction of the PG content to 20 mol% interactions are weaker and/or an in average more tilted orientation is observed. Fluorescence spectroscopy of differently labelled lipids is in agreement of an interfacial localisation of both helices where the C-terminal end is in a less hydrophobic environment. By inserting into the membrane interface and interacting differently with PE and PG the peptides probably induce high curvature strain which result in membrane openings and rupture.
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Affiliation(s)
- Jörg Andrä
- Department of Biotechnology, Faculty of Life Sciences, Hamburg University of Applied Sciences, Hamburg, Germany.
| | | | - U S Sudheendra
- University of Strasbourg / CNRS, UMR7177, Chemistry Institute, Strasbourg, France
| | - Marc Prudhon
- University of Strasbourg / CNRS, UMR7177, Chemistry Institute, Strasbourg, France
| | - Gerald Brezesinski
- Department of Physics, TU Darmstadt, Darmstadt, Germany; Department of Interfaces, Max Planck Institute of Colloids and Interfaces, Potsdam, Germany
| | - Claudia Zschech
- Department of Interfaces, Max Planck Institute of Colloids and Interfaces, Potsdam, Germany
| | | | - Matthias Leippe
- Comparative Immunobiology, Zoological Institute, Christian-Albrechts-Universität zu Kiel, Kiel, Germany
| | - Thomas Gutsmann
- Research Center Borstel, Leibniz Lung Center, Borstel, Germany; Centre for Structural Systems Biology, Hamburg, Germany
| | - Burkhard Bechinger
- University of Strasbourg / CNRS, UMR7177, Chemistry Institute, Strasbourg, France; Institut Universitaire de France, 75005 Paris, France.
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Qiu D, Ye Y, Ke M, Xu N, Zhang Z, Zhang F, Kang J, Yu Y, Lu T, Qian H. Effects of chiral herbicide dichlorprop on Arabidopsis thaliana metabolic profile and its implications for microbial communities in the phyllosphere. Environ Sci Pollut Res Int 2022; 29:28256-28266. [PMID: 34988791 DOI: 10.1007/s11356-021-17936-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2021] [Accepted: 11/30/2021] [Indexed: 06/14/2023]
Abstract
Dichlorprop (2-(2,4-dichlorophenoxy) propionic acid, DCPP), a commonly used herbicide for weed control, can be residually detected in soil. It is still unclear whether chiral DCPP exerts an enantioselective adverse effect on plant metabolism and the microbial community of the phyllosphere. In this study, we selected Arabidopsis thaliana as a model plant to explore the effects of R- and S-DCPP enantiomers on plant physiological activities, metabolism, and associated changes in the phyllosphere microbial community. Results indicated that the fresh weight of plants decreased by 37.6% after R-DCPP treatment, whereas it increased by 7.6% after S-DCPP treatment. The R-DCPP enantiomer also caused stronger disturbance to leaf morphology, mesophyll cell structure, and leaf metabolites compared with S-DCPP. GC-MS analysis of DCPP-treated Arabidopsis leaves pointed out a differential profile mostly in carbohydrates, organic acids, and fatty acids, between S-DCPP and R-DCPP treatments. The diversity of phyllospheric microorganisms decreased and the stability of microbial community in the phyllosphere increased after R-DCPP treatment, whereas the opposite result was detected after S-DCPP exposure. The correlation analysis revealed that chiral herbicides may affect microbial communities in the phyllosphere by influencing leaf metabolism, while sugars and terpenoids were considered the main factors in reshaping the microbial community structure in the phyllosphere. Our study provides a new perspective for evaluating the effect of residual DCPP enantiomers on plant physiology and corresponding phyllosphere microorganism changes via the regulation of leaf metabolism, and clarifies the ecological risk of DCPP enantiomer application in agriculture.
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Affiliation(s)
- Danyan Qiu
- College of Environment, Zhejiang University of Technology, Hangzhou, 310032, People's Republic of China
| | - Yizhi Ye
- College of Environment, Zhejiang University of Technology, Hangzhou, 310032, People's Republic of China
| | - Mingjing Ke
- College of Environment, Zhejiang University of Technology, Hangzhou, 310032, People's Republic of China
| | - Nuohan Xu
- College of Environment, Zhejiang University of Technology, Hangzhou, 310032, People's Republic of China
| | - Zhenyan Zhang
- College of Environment, Zhejiang University of Technology, Hangzhou, 310032, People's Republic of China
| | - Fan Zhang
- College of Environment, Zhejiang University of Technology, Hangzhou, 310032, People's Republic of China
| | - Jian Kang
- College of Environment, Zhejiang University of Technology, Hangzhou, 310032, People's Republic of China
| | - Yitian Yu
- College of Environment, Zhejiang University of Technology, Hangzhou, 310032, People's Republic of China
| | - Tao Lu
- College of Environment, Zhejiang University of Technology, Hangzhou, 310032, People's Republic of China
| | - Haifeng Qian
- College of Environment, Zhejiang University of Technology, Hangzhou, 310032, People's Republic of China.
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Halder A, Karmakar S. An evidence of pores in phospholipid membrane induced by an antimicrobial peptide NK-2. Biophys Chem 2022; 282:106759. [PMID: 35008010 DOI: 10.1016/j.bpc.2022.106759] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Revised: 11/27/2021] [Accepted: 01/02/2022] [Indexed: 11/19/2022]
Abstract
NK-2, a peptide derived from a cationic core region of NK-lysin, has emerged as a promising candidate for new antibiotics. In contrast to classical antibiotics, antimicrobial peptides target bacterial membranes and disintegrate the membrane by forming the transmembrane pores. However, complete understanding of the precise mechanisms of cellular apoptosis and molecular basis of membrane selectivity is still in dispute. In the present study, we have shown that NK-2 forms trans-membrane pores on negatively charged phospholipid membranes using phase contrast microscopy. As bacteria mimicking membranes, we have chosen large unilamellar vesicles (LUV) and giant unilamellar vesicles (GUV) composed of negatively charged phospholipid, dioleoyl phosphatidyl glycerol (DOPG) and neutral phospholipid, dioleoyl phophatidylcholine (DOPC). Leakage of internal fluid of giant unilamellar vesicles (GUV), leading to decrease in intensity in the halo region of phase contrast micrographs, suggests the formation of transmembrane pores. No such reduction of intensity in the halo region of DOPC was observed, indicating, neutral vesicles does not exhibit pores. Rate constant reckoned from the decaying intensity in the halo region was found to be 0.007 s-1. Further, significant interaction of NK-2 with anionic membranes has been envisaged from zeta potential and dynamic light scattering. Binding free energy and other interaction parameters have been delineated using theoretical ansatz. A proliferation of average Size of anionic LUV on increasing NK-2 concentration indicates membrane-membrane interaction leading to peptide induced large aggregates of vesicles.
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Affiliation(s)
- Animesh Halder
- Soft matter and Biophysics Laboratory, Department of Physics, Jadavpur University, 188, Raja S. C. Mullick Road, Kolkata 700032, India
| | - Sanat Karmakar
- Soft matter and Biophysics Laboratory, Department of Physics, Jadavpur University, 188, Raja S. C. Mullick Road, Kolkata 700032, India.
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4
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Zhang Q, Ye Y, Qu Q, Yu Y, Jin M, Lu T, Qian H. Enantioselective metabolomic modulations in Arabidopsis thaliana leaf induced by the herbicide dichlorprop. Sci Total Environ 2021; 797:149015. [PMID: 34346373 DOI: 10.1016/j.scitotenv.2021.149015] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2021] [Revised: 07/09/2021] [Accepted: 07/09/2021] [Indexed: 06/13/2023]
Abstract
Over 40% of herbicides used today are chiral. Dichlorprop (2, 4-DCPP) is a widely used typical broad-spectrum chiral aryloxyphenoxy propionic acid (AOPP) herbicide. However, the molecular mechanism of the enantioselectivity of DCPP enantiomers (S-DCPP and R-DCPP) and their effects on non-target organisms are remain unclear. In the present study, the model plant Arabidopsis thaliana was treated by DCPP enantiomers to directly reveal the effects of DCPP enantiomers on plant growth, as well as metabolic profile. Results showed that the enantioselectivity embodied in that R-DCPP treatment led to the decrease of shoot weight, the significantly variation on morphology of shoot and root, oxidative damage, et al., while the plant morphology also changes to a certain extent associated oxidative damage after treated by S-DCPP. By using metabolomic analysis, it was found that R-DCPP had significant effects on A. thaliana leaf metabolism, including lactose metabolism, starch and sucrose metabolism, TCA cycle, fatty acid biosynthesis pathway and pentose phosphate pathway, and accumulated a lot of antioxidants in plant leaves, while the amino acids and some terpenoids increased in S-DCPP group. Our study provides a new direction to explore the relationship between chiral herbicides on leaf metabolism, and the effect of this relationship on the plant growth.
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Affiliation(s)
- Qi Zhang
- College of Environment, Zhejiang University of Technology, Hangzhou 310014, PR China
| | - Yizhi Ye
- College of Environment, Zhejiang University of Technology, Hangzhou 310014, PR China
| | - Qian Qu
- College of Environment, Zhejiang University of Technology, Hangzhou 310014, PR China
| | - Yitian Yu
- College of Environment, Zhejiang University of Technology, Hangzhou 310014, PR China
| | - Mingkang Jin
- Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, PR China
| | - Tao Lu
- College of Environment, Zhejiang University of Technology, Hangzhou 310014, PR China.
| | - Haifeng Qian
- College of Environment, Zhejiang University of Technology, Hangzhou 310014, PR China
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Chen H, Qin Y, Pu J, Hu J, Wen Y. Phytotoxicity of the chiral herbicide dichlorprop: Cross-talk between nitric oxide, reactive oxygen species and phytohormones. Sci Total Environ 2021; 788:147866. [PMID: 34134377 DOI: 10.1016/j.scitotenv.2021.147866] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 05/13/2021] [Accepted: 05/14/2021] [Indexed: 06/12/2023]
Abstract
Nitric oxide (NO), reactive oxygen species (ROS), and phytohormones in plants often initiate responses to sources of abiotic stress. However, we have a poor understanding of the cross-talk between NO, ROS, and phytohormones during exogenous chiral auxin-induced phytotoxicity. In this study, the toxicity of the chiral synthetic auxin herbicide dichlorprop (DCPP) to Arabidopsis thaliana, as well as the mutual regulation of NO, hydrogen peroxide (H2O2), superoxide anion (O2.-), and phytohormones at the enantiomeric level was investigated. The ROS production exhibited an enantioselective manner, further, that was positively correlated with the change of the morphological indicators. This confirmed that ROS played an important role in the enantioselective effect of DCPP. The distribution of ROS and NO was partially overlapped, indicating that the production of NO may be affected by ROS, and also related to the degree of plant damage. In terms of phytohormones, the level of salicylic acid (SA), jasmonic acid (JA), and abscisic acid (ABA) in the whole plant increased as the (R)-DCPP concentration applied increased, however, the trend has changed, when the data of leaves and roots was discussed separately. The results revealed that the redistribution of phytohormones may exist between leaves and roots, caused by the joint action of ROS and NO. The differences in the biological activity identified between the two enantiomers in this study enhance our understanding of the toxicity mechanism of exogenous auxin via their effects on phytohormones.
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Affiliation(s)
- Hui Chen
- College of Science and Technology, Ningbo University, Cixi 315302, China
| | - Yongxiang Qin
- College of Science and Technology, Ningbo University, Cixi 315302, China
| | - Jiawei Pu
- College of Science and Technology, Ningbo University, Cixi 315302, China
| | - Jinxing Hu
- College of Science and Technology, Ningbo University, Cixi 315302, China
| | - Yuezhong Wen
- MOE Key Laboratory of Environmental Remediation & Ecosystem Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China.
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Li J, Chen S, Huang J, Chen H, Chen Z, Wen Y. New Target in an Old Enemy: Herbicide ( R)-Dichlorprop Induces Ferroptosis-like Death in Plants. J Agric Food Chem 2021; 69:7554-7564. [PMID: 34196530 DOI: 10.1021/acs.jafc.1c02102] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Iron is an essential microelement in plants that is involved in several growth processes. The use of herbicides may cause the abnormal aggregation of iron in leaves, but the regulatory mechanisms underlying this phenomenon remain unclear. Here, we show that chiral herbicide (R)-dichlorprop ((R)-DCPP) triggers ferroptosis-like death in Arabidopsis thaliana. (R)-DCPP led to reactive oxygen species (ROS) accumulation and iron aggregation, and these processes were iron dependent. Under (R)-DCPP treatment, ROS, lipid hydrogen peroxides, and malondialdehyde were significantly accumulated. In addition, (R)-DCPP induced the depletion of glutathione, ascorbic acid, and glutathione peroxidase as well as the accumulation of toxic lipid peroxides. Thus, oxidation imbalance led to cell death, and this mode of action could be inhibited by the ferroptosis inhibitor ferrostatin-1 or ciclopirox olamine. NADPH oxidases were found to be involved in herbicide-induced ROS accumulation, and lipoxygenase and NADPH cytochrome P450 oxidase were shown to positively regulate (R)-DCPP-induced lipid peroxidation. Overall, these results indicate that the iron- and ROS-dependent signaling cascades were involved in the (R)-DCPP-induced phytotoxicity pathway, which disrupted the structure of plant cell membranes and triggered ferroptosis. Generally, this study provides new insight into the mechanisms of pesticide phytotoxicity and suggests new therapeutic directions to protect nontarget plants.
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Affiliation(s)
- Jun Li
- MOE Key Laboratory of Environmental Remediation & Ecosystem Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China
| | - Siyu Chen
- MOE Key Laboratory of Environmental Remediation & Ecosystem Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China
| | - Jinye Huang
- MOE Key Laboratory of Environmental Remediation & Ecosystem Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China
| | - Hui Chen
- College of Science and Technology, Ningbo University, Ningbo 315211, China
| | - Zunwei Chen
- Department of Veterinary Integrative Biosciences, Texas A&M University, College Station, Texas 77843, United States
| | - Yuezhong Wen
- MOE Key Laboratory of Environmental Remediation & Ecosystem Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China
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Yu H, Huang S, Chen P, Ji M, Cui H, Chen J, Li X. Different leaf-mediated deposition, absorbed and metabolism behaviors of 2,4-D isooctyl ester between Triticum aestivum and Aegilops tauschii Coss. Pestic Biochem Physiol 2021; 175:104848. [PMID: 33993966 DOI: 10.1016/j.pestbp.2021.104848] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Revised: 03/23/2021] [Accepted: 03/31/2021] [Indexed: 06/12/2023]
Abstract
Tausch's goatgrass (Aegilops tauschii Coss.), is a major weed species, infesting wheat (Triticum aestivum) fields in China. 2,4-D isooctyl ester is widely used for broadleaf weed control and selected as a tool to study the differences between, A. tauschii and T. aestivum. In this study, we measured the growth responses of these species to 2,4-D isooctyl ester and found that T. aestivum was more sensitive to the herbicide than A. tauschii. To clarify the reasons for this difference, we measured the leaf-mediated deposition, absorption and metabolism of 2,4-D isooctyl ester and the expression of auxin receptor transport inhibitor response (TIR1) gene in T. aestivum and A. tauschii. The results indicated that the deposition of 2,4-D isooctyl ester droplets may be lower on A. tauschii than on T. aestivum, because of the increased contact angle and greater density of trichomes on the leaves of the former. A distinct increase in 2,4-D isooctyl ester uptake was detected in T. aestivum during the entire experimental period, and the rate was 2.2-fold greater than that in A. tauschii at 6 h after treatment. Compared with A. tauschii, T. aestivum exhibited a greater accumulation of primary metabolite 2,4-D in plants, which may be responsible for the different responses of the two species. Additionally, the absolute expression level of TIR1 was clearly greater in T. aestivum than that in A. tauschii. These data will be helpful to further understand the differences between T. aestivum and A. tauschii, which may provide a unique perspective for the development and identification of new target compounds that are effective against this weed species.
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Affiliation(s)
- Haiyan Yu
- Key Laboratory of Weed Biology and Management, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, No.2 Yuanmingyuanxilu, Beijing 100193, China
| | - Songtao Huang
- Key Laboratory of Weed Biology and Management, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, No.2 Yuanmingyuanxilu, Beijing 100193, China
| | - Pingping Chen
- Key Laboratory of Weed Biology and Management, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, No.2 Yuanmingyuanxilu, Beijing 100193, China
| | - Meijing Ji
- Key Laboratory of Weed Biology and Management, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, No.2 Yuanmingyuanxilu, Beijing 100193, China
| | - Hailan Cui
- Key Laboratory of Weed Biology and Management, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, No.2 Yuanmingyuanxilu, Beijing 100193, China
| | - Jingchao Chen
- Key Laboratory of Weed Biology and Management, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, No.2 Yuanmingyuanxilu, Beijing 100193, China
| | - Xiangju Li
- Key Laboratory of Weed Biology and Management, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, No.2 Yuanmingyuanxilu, Beijing 100193, China.
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Liu Z, Wang Y, Pu W, Zhu H, Liang J, Wu J, Hong L, Guan P, Hu J. 4-CPA (4-Chlorophenoxyacetic Acid) Induces the Formation and Development of Defective "Fenghou" ( Vitis vinifera × V. labrusca) Grape Seeds. Biomolecules 2021; 11:biom11040515. [PMID: 33808413 PMCID: PMC8067128 DOI: 10.3390/biom11040515] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Revised: 03/19/2021] [Accepted: 03/22/2021] [Indexed: 12/13/2022] Open
Abstract
For some horticultural plants, auxins can not only induce normal fruit setting but also form fake seeds in the induced fruits. This phenomenon is relatively rare, and, so far, the underlying mechanism remains unclear. In this study, “Fenghou” (Vitis vinifera × V. labrusca) grapes were artificially emasculated before flowering and then sprayed with 4-CPA (4-chlorophenoxyacetic acid) to analyze its effect on seed formation. The results show that 4-CPA can induce normal fruit setting in “Fenghou” grapes. Although more seeds were detected in the fruits of the 4-CPA-treated grapevine, most seeds were immature. There was no significant difference in the seed shape; namely, both fruit seeds of the grapevines with and without 4-CPA treatment contained a hard seed coat. However, the immature seeds lacked embryo and endosperm tissue and could not germinate successfully; these were considered defective seeds. Tissue structure observation of defective seeds revealed that a lot of tissue redifferentiation occurred at the top of the ovule, which increased the number of cell layers of the outer integument; some even differentiated into new ovule primordia. The qRT-PCR results demonstrated that 4-CPA application regulated the expression of the genes VvARF2 and VvAP2, which are associated with integument development in “Fenghou” grape ovules. Together, this study evokes the regulatory role of 4-CPA in the division and continuous redifferentiation of integument cells, which eventually develop into defective seeds with thick seed coats in grapes.
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Affiliation(s)
- Zhenhua Liu
- College of Horticulture, China Agricultural University, Beijing 100193, China; (Z.L.); (Y.W.); (W.P.); (H.Z.); (J.L.); (J.W.); (L.H.)
| | - Yan Wang
- College of Horticulture, China Agricultural University, Beijing 100193, China; (Z.L.); (Y.W.); (W.P.); (H.Z.); (J.L.); (J.W.); (L.H.)
| | - Wenjiang Pu
- College of Horticulture, China Agricultural University, Beijing 100193, China; (Z.L.); (Y.W.); (W.P.); (H.Z.); (J.L.); (J.W.); (L.H.)
| | - Haifeng Zhu
- College of Horticulture, China Agricultural University, Beijing 100193, China; (Z.L.); (Y.W.); (W.P.); (H.Z.); (J.L.); (J.W.); (L.H.)
| | - Jinjun Liang
- College of Horticulture, China Agricultural University, Beijing 100193, China; (Z.L.); (Y.W.); (W.P.); (H.Z.); (J.L.); (J.W.); (L.H.)
| | - Jiang Wu
- College of Horticulture, China Agricultural University, Beijing 100193, China; (Z.L.); (Y.W.); (W.P.); (H.Z.); (J.L.); (J.W.); (L.H.)
| | - Liang Hong
- College of Horticulture, China Agricultural University, Beijing 100193, China; (Z.L.); (Y.W.); (W.P.); (H.Z.); (J.L.); (J.W.); (L.H.)
| | - Pingyin Guan
- Molecular Cell Biology, Botanical Institute, Karlsruhe Institute of Technology, 76131 Karlsruhe, Germany;
| | - Jianfang Hu
- College of Horticulture, China Agricultural University, Beijing 100193, China; (Z.L.); (Y.W.); (W.P.); (H.Z.); (J.L.); (J.W.); (L.H.)
- Correspondence: ; Tel.: +86-010-62732488
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Youfeng Z, Dongdong Z, Ling H. Enantioselective biodegradation and enantiomerization of dichlorprop in soils. Chemosphere 2020; 258:127322. [PMID: 32563915 DOI: 10.1016/j.chemosphere.2020.127322] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2019] [Revised: 05/21/2020] [Accepted: 06/02/2020] [Indexed: 06/11/2023]
Abstract
The dissipation of racemic, R-, and S- dichlorprop (DCPP) in four soils were studied in the laboratory. The half-lives of racemic DCPP were from 10.5 to 19.8 days. Preferential degradation of R- or S-DCPP was detected in all soils, even in one soil that the apparent enantiomeric fraction remained constant during incubation. The enantiomerization of DCPP was found to proceed in both directions, except in forest soil that no enantiomerization of S- to R-DCPP was observed. The isomerization equilibrium constant (K = kRS/kSR) in two vegetable soils were 0.54 and 0.53, respectively, favoring herbicidally active R enantiomer, while in paddy soil K was 1.60, favoring an inversion of R into S enantiomer. Real-time PCR showed that the rdpA gene was not detected in all indigenous and DCPP amended microcosms probably because of relative short incubation time and low amendment concentrations. In contrast, the sdpA gene was present in indigenous soils and significantly elevated after DCPP addition with the highest relative abundance around day 10 in all microcosms. Illumina sequencing of the 16S rRNA gene showed that the relative abundance of Proteobacteria significantly increased in all DCPP treated soils. DCPP-degrading related families, Sphingomonadaceae and Comamonadaceae, enhanced in all soils, while Burkholderiaceae elevated only in paddy soil with preferential degradation of S-DCPP and Pseudomonadaceae only in forest soil with R-enantiomer preference. The sdpA gene sequencing revealed that about 92%-99% of bacteria harboring sdpA genes in studied soils belong to Alphaproteobacteria.
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Affiliation(s)
- Zhu Youfeng
- MOE Key Lab of Environmental Remediation and Ecosystem Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, 310058, PR China; Zhejiang Provincial Key Laboratory of Organic Pollution Process and Control, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, 310058, PR China.
| | - Zhang Dongdong
- College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, 310058, PR China
| | - He Ling
- College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, 310058, PR China
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10
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Su Y, Wang S, Zhang N, Cui P, Gao Y, Bao T. Zr-MOF modified cotton fiber for pipette tip solid-phase extraction of four phenoxy herbicides in complex samples. Ecotoxicol Environ Saf 2020; 201:110764. [PMID: 32480162 DOI: 10.1016/j.ecoenv.2020.110764] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2020] [Revised: 05/11/2020] [Accepted: 05/13/2020] [Indexed: 05/19/2023]
Abstract
Phenoxy herbicides are widely applied in agricultural weeding. The determination of herbicides is important in environmental protection, agricultural production, food safety, and public health. In this study, a facile and efficient analytical method was proposed for the trace detection of phenoxy herbicides in soil, cucumber, and tap water samples by coupling pipette tip solid phase extraction (PT-SPE) with high performance liquid chromatography. UiO-66-funtionalized cotton (Cotton@UiO-66) was packed into pipette-tip as sorbent to fabricate extraction device. The modification of UiO-66 on cotton fiber was confirmed using scanning electron microscope, Fourier transform infrared spectroscopy, and X-ray diffraction. The main factors affecting the adsorption of Cotton@UiO-66 for four phenoxy herbicides were evaluated by response surface methodology in detail. Under optimized conditions, Cotton@UiO-66 displayed excellent properties in the extraction of phenoxy herbicides with good peak shape. Linear ranges of 4-chlorophenoxyacetic acid, dicamba, 2,4-dichlorophenoxyacetic acid, and 2-(2,4-dichlorophenoxy) propionic acid were 1.4-72 μg/L, 5.6-280 μg/L, 2.8-140 μg/L and 3.2-160 μg/L (RSDs < 6.3%), respectively. The recoveries were between 83.3 and 106.8% with RSDs <6.7%, with detection limits ranging from 0.1 μg/L to 0.3 μg/L. The results show that Cotton@UiO-66 in PT-SPE is an effective method for monitoring phenoxy herbicides in complex samples.
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Affiliation(s)
- Ying Su
- School of Pharmacy, Health Science Center, Xi'an Jiaotong University, Xi'an, 710061, China; Shaanxi Engineering Research Center of Cardiovascular Drugs Screening & Analysis, Xi'an, 710061, China
| | - Sicen Wang
- School of Pharmacy, Health Science Center, Xi'an Jiaotong University, Xi'an, 710061, China; Shaanxi Engineering Research Center of Cardiovascular Drugs Screening & Analysis, Xi'an, 710061, China
| | - Nan Zhang
- School of Pharmacy, Health Science Center, Xi'an Jiaotong University, Xi'an, 710061, China; Shaanxi Engineering Research Center of Cardiovascular Drugs Screening & Analysis, Xi'an, 710061, China
| | - Ping Cui
- School of Pharmacy, Health Science Center, Xi'an Jiaotong University, Xi'an, 710061, China; Shaanxi Engineering Research Center of Cardiovascular Drugs Screening & Analysis, Xi'an, 710061, China
| | - Yan Gao
- School of Pharmacy, Health Science Center, Xi'an Jiaotong University, Xi'an, 710061, China; Shaanxi Engineering Research Center of Cardiovascular Drugs Screening & Analysis, Xi'an, 710061, China
| | - Tao Bao
- School of Pharmacy, Health Science Center, Xi'an Jiaotong University, Xi'an, 710061, China; Shaanxi Engineering Research Center of Cardiovascular Drugs Screening & Analysis, Xi'an, 710061, China.
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11
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Zhu Y, Guo J. Impact of dichlorprop on soil microbial community structure and diversity during its enantioselective biodegradation in agricultural soils. J Environ Sci Health B 2020; 55:974-982. [PMID: 32757814 DOI: 10.1080/03601234.2020.1802186] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Enantioselective biodegradation of racemic dichlorprop in two soils was investigated in the laboratory. Chiral separation of racemic dichlorprop was achieved by using HPLC with Phenomenex Lux Amylose-2. The first-order kinetic model fitted well the dissipation data of racemic dichlorprop and its pure R- and S-enantiomers. S-dichlorprop was preferentially degraded in both soils and enantioselectivity was affected by soil pH. The half-lives (DT50) of S-dichlorprop were 8.22 days in soil A and 8.06 days in soil D, while R-dichlorprop was more persistent with DT50 of 12.93 days in soil A and 12.38 days in soil D, respectively. Dichlorprop dissipated faster in soil D with lower organic matter content. In sterilized soils, neglected dissipation was observed and enantiomer fraction values remained constant, indicating that the enantioselective degradation was mainly controlled by soil microorganisms. Soil microbial community structure and diversity was assessed by Illumina MiSeq sequencing of 16S rRNA genes from dichlorprop and no dichlorprop contaminated microcosms. Compared with controls, dichlorprop application had no significant effect on microbial community structures at phylum level, but increased bacterial diversity and dichlorprop degradation related taxa in both soils. S-dichlorprop preferential degradation might be attributed to the S-enantiomer preferred degraders in the family of Sphingomonadaceae.
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Affiliation(s)
- Youfeng Zhu
- Key Lab of Environmental Remediation and Ecosystem Health, Ministry of Education, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, P. R. China
| | - Jiarong Guo
- Center for Microbial Ecology, Michigan State University, East Lansing, Michigan, USA
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12
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Zhang L, Hang P, Zhou XY, Qiao WJ, Jiang JD. Enantioselective Catabolism of the Two Enantiomers of the Phenoxyalkanoic Acid Herbicide Dichlorprop by Sphingopyxis sp. DBS4. J Agric Food Chem 2020; 68:6967-6976. [PMID: 32530641 DOI: 10.1021/acs.jafc.0c01066] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Dichlorprop [(RS)-2-(2,4-dichlorophenoxy)propanoic acid; DCPP], an important phenoxyalkanoic acid herbicide (PAAH), is extensively used in the form of racemic mixtures (Rac-DCPP), and the environmental fates of both DCPP enantiomers [(R)-DCPP and (S)-DCPP] mediated by microorganisms are of great concern. In this study, a bacterial strain Sphingopyxis sp. DBS4 was isolated from contaminated soil and was capable of utilizing both (R)-DCPP and (S)-DCPP as the sole carbon source for growth. Strain DBS4 preferentially catabolized (S)-DCPP as compared to (R)-DCPP. The optimal conditions for Rac-DCPP degradation by strain DBS4 were 30 °C and pH 7.0. In addition to Rac-DCPP, other PAAHs such as (RS)-2-(4-chloro-2-methylphenoxy)propanoic acid, 2,4-dichlorophenoxyacetic acid, 4-chloro-2-methylphenoxyacetic acid, and 2,4-dichlorophenoxyacetic acid butyl ester could also be catabolized by strain DBS4. Bioremediation of Rac-DCPP-contaminated soil by inoculation of strain DBS4 exhibited an effective removal of both (R)-DCPP and (S)-DCPP from the soil. Due to its broad substrate spectrum, strain DBS4 showed great potential in the bioremediation of PAAH-contaminated sites.
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Affiliation(s)
- Long Zhang
- Department of Microbiology, Key Lab of Microbiology for Agricultural Environment, Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, 210095 Nanjing, China
- College of Life Sciences, Huaibei Normal University, 235000 Huaibei, China
| | - Ping Hang
- Department of Microbiology, Key Lab of Microbiology for Agricultural Environment, Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, 210095 Nanjing, China
| | - Xi-Yi Zhou
- Department of Microbiology, Key Lab of Microbiology for Agricultural Environment, Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, 210095 Nanjing, China
| | - Wen-Jing Qiao
- Department of Microbiology, Key Lab of Microbiology for Agricultural Environment, Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, 210095 Nanjing, China
| | - Jian-Dong Jiang
- Department of Microbiology, Key Lab of Microbiology for Agricultural Environment, Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, 210095 Nanjing, China
- Jiangsu Provincial Key Lab for Organic Solid Waste Utilization, Nanjing Agricultural University, 210095 Nanjing, China
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13
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Zheng X, Liu C, Hu J. Residues and Dietary Risk Assessments of 2,4-D Isooctyl Ester, Metribuzin, Acetochlor, and 2-Ethyl-6-methylaniline in Corn or Soybean Fields. J Agric Food Chem 2020; 68:4315-4324. [PMID: 32202777 DOI: 10.1021/acs.jafc.0c00193] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Since 2,4-dichlorophenoxy acetic acid (2,4-D) was discovered in the 1940s, 2,4-D and its derivatives remain among most commonly used herbicides in the world. There have been recent increases in using 2,4-D products in a combination with other herbicides such as metribuzin and acetochlor to control noxious weeds. However, accurate analysis of 2,4-D isooctyl ester remains to be improved due to long analysis time and rapid conversion of the ester to acid (i.e., under-reporting residues). In this work, a simple hydrolysis procedure was introduced to provide a quantitative hydrolytic rate of the ester (>95%) and did not affect the other pH-sensitive compounds. Analysis parameters and sample pretreatments were optimized for improved selectivity and accuracy. The hydrolysis-QuEChERS (quick, easy, cheap, effective, rugged, and safe) technique for multidetermination of 2,4-D isooctyl ester, metribuzin, acetochlor, and 2-ethyl-6-methylaniline in corn and soybeans via high performance liquid chromatography-tandem mass spectrometry was established. The method had average recoveries of 74-109% with relative standard deviations ≤13.5% and limits of quantifications (LOQs) of 0.05 mg/kg. The terminal residues of these compounds found in real edible matrixes were less than the corresponding LOQs at harvest time. The risk quotients were far below 100%, indicating a low health risk to consumers.
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Affiliation(s)
- Xutian Zheng
- College of Chemistry and Biological Engineering, University of Science and Technology Beijing, Beijing 100083, People's Republic of China
| | - Chaolun Liu
- Chemistry Department, University of Hawaii at Manoa 2545 The Mall, Honolulu, Hawaii 96822,United States
| | - Jiye Hu
- College of Chemistry and Biological Engineering, University of Science and Technology Beijing, Beijing 100083, People's Republic of China
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14
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Biancolillo A, Maggi MA, Bassi S, Marini F, D’Archivio AA. Retention Modelling of Phenoxy Acid Herbicides in Reversed-Phase HPLC under Gradient Elution. Molecules 2020; 25:molecules25061262. [PMID: 32168813 PMCID: PMC7144001 DOI: 10.3390/molecules25061262] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2020] [Revised: 03/01/2020] [Accepted: 03/11/2020] [Indexed: 12/02/2022] Open
Abstract
Phenoxy acid herbicides are used worldwide and are potential contaminants of drinking water. Reversed phase high-performance liquid chromatography (RP-HPLC) is commonly used to monitor phenoxy acid herbicides in water samples. RP-HPLC retention of phenoxy acids is affected by both mobile phase composition and pH, but the synergic effect of these two factors, which is also dependent on the structure and pKa of solutes, cannot be easily predicted. In this paper, to support the setup of RP-HPLC analysis of phenoxy acids under application of linear mobile phase gradients we modelled the simultaneous effect of the molecular structure and the elution conditions (pH, initial acetonitrile content in the eluent and gradient slope) on the retention of the solutes. In particular, the chromatographic conditions and the molecular descriptors collected on the analyzed compounds were used to estimate the retention factor k by Partial Least Squares (PLS) regression. Eventually, a variable selection approach, Genetic Algorithms, was used to reduce the model complexity and allow an easier interpretation. The PLS model calibrated on the retention data of 15 solutes and successively tested on three external analytes provided satisfying and reliable results.
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Affiliation(s)
- Alessandra Biancolillo
- Dipartimento di Scienze Fisiche e Chimiche, Università degli Studi dell’Aquila, Via Vetoio, Coppito, 67100 L’Aquila (AQ), Italy;
| | - Maria Anna Maggi
- Hortus Novus srl, Via Campo Sportivo 2, Canistro, 67100 L’Aquila, Italy;
| | - Sebastian Bassi
- Dipartimento di Chimica, Università degli Studi di Roma “La Sapienza”, Piazzale Aldo Moro 5, 00185 Roma, Italy; (S.B.); (F.M.)
| | - Federico Marini
- Dipartimento di Chimica, Università degli Studi di Roma “La Sapienza”, Piazzale Aldo Moro 5, 00185 Roma, Italy; (S.B.); (F.M.)
| | - Angelo Antonio D’Archivio
- Dipartimento di Scienze Fisiche e Chimiche, Università degli Studi dell’Aquila, Via Vetoio, Coppito, 67100 L’Aquila (AQ), Italy;
- Correspondence:
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15
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Muszyński P, Brodowska MS, Paszko T. Occurrence and transformation of phenoxy acids in aquatic environment and photochemical methods of their removal: a review. Environ Sci Pollut Res Int 2020; 27:1276-1293. [PMID: 31788729 PMCID: PMC6994553 DOI: 10.1007/s11356-019-06510-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Accepted: 09/10/2019] [Indexed: 05/07/2023]
Abstract
The article presents the behavior of phenoxy acids in water, the levels in aquatic ecosystems, and their transformations in the water environment. Phenoxy acids are highly soluble in water and weakly absorbed in soil. These highly mobile compounds are readily transported to surface and groundwater. Monitoring studies conducted in Europe and in other parts of the world indicate that the predominant phenoxy acids in the aquatic environment are mecoprop, 4-chloro-2-methylphenoxyacetic acid (MCPA), dichlorprop, 2,4-dichlorophenoxyacetic acid (2,4-D), and their metabolites which are chlorophenol derivatives. In water, the concentrations of phenoxy acids are effectively lowered by hydrolysis, biodegradation, and photodegradation, and a key role is played by microbial decomposition. This process is determined by the qualitative and quantitative composition of microorganisms, oxygen levels in water, and the properties and concentrations of phenoxy acids. In shallow and highly insolated waters, phenoxy acids can be decomposed mainly by photodegradation whose efficiency is determined by the form of the degraded compound. Numerous studies are underway on the use of advanced oxidation processes (AOPs) to remove phenoxy acids. The efficiency of phenoxy acid degradation using AOPs varies depending on the choice of oxidizing system and the conditions optimizing the oxidation process. Most often, methods combining UV radiation with other reagents are used to oxidize phenoxy acids. It has been found that this solution is more effective compared with the oxidation process carried out using only UV.
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Affiliation(s)
- Paweł Muszyński
- Department of Chemistry, University of Life Sciences in Lublin, Akademicka Street 15, 20-950, Lublin, Poland
| | - Marzena S Brodowska
- Department of Agricultural and Environmental Chemistry, University of Life Sciences in Lublin, Akademicka Street 15, 20-950, Lublin, Poland.
| | - Tadeusz Paszko
- Department of Chemistry, University of Life Sciences in Lublin, Akademicka Street 15, 20-950, Lublin, Poland
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16
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Chen S, Chen H, Chen Z, Wen Y, Liu W. Enantioselective Phytotoxic Disturbances of Fatty Acids in Arabidopsis thaliana by Dichlorprop. Environ Sci Technol 2019; 53:9252-9259. [PMID: 31290320 DOI: 10.1021/acs.est.9b03744] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Plant fatty acids have indispensable physiological functions and nutritional value. However, the overuse of herbicides may cause phytotoxic disturbances of fatty acids in nontarget plants while spraying for weeds. Evidence has shown that the herbicide dichlorprop can inhibit the activity of acetyl-CoA carboxylase (ACCase), a key enzyme involved in fatty acid synthesis. However, the enantioselective phytotoxic effects of dichlorprop enantiomers ((R)-dichlorprop and (S)-dichlorprop) on fatty acids and their related mechanisms remain unclear. To solve this issue, the enantioselective phytotoxicity of dichlorprop in the model plant species Arabidopsis thaliana (A. thaliana) with a focus on fatty acids was evaluated for the first time. The results indicated a significant difference in enantioselectivity and that exposure to (R)-dichlorprop can cause marked fatty acid disturbances in nontarget plant species. Specifically, (R)-dichlorprop decreased the content of three fatty acids by more than 50% by inhibiting the activity of ACCase. In addition, increased malondialdehyde (MDA) and lipid hydroperoxides (LOOHs) contents and membrane permeability reflected herbicide-induced lipid peroxidation, which decreased the unsaturation of fatty acids in membranes and further influenced membrane composition and function. Moreover, an increased level of glutathione peroxidase (GPX) and cytochrome P450 (CYP450) reflected a plant stress-induced response. To summarize, fatty acids represent a new perspective for evaluating the toxicity of chiral pesticides, contributing to a better understanding of the enantioselective phytotoxicity and mechanisms of dichlorprop, and providing evidence for herbicide security and risk assessments.
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Affiliation(s)
- Siyu Chen
- MOE Key Laboratory of Environmental Remediation & Ecosystem Health, Institute of Environmental Health, College of Environmental and Resource Sciences , Zhejiang University , Hangzhou 310058 , China
| | - Hui Chen
- College of Science and Technology , Ningbo University , Ningbo 315211 , China
| | - Zunwei Chen
- Department of Veterinary Integrative Biosciences , Texas A&M University , College Station , Texas 77843 , United States
| | - Yuezhong Wen
- MOE Key Laboratory of Environmental Remediation & Ecosystem Health, Institute of Environmental Health, College of Environmental and Resource Sciences , Zhejiang University , Hangzhou 310058 , China
| | - Weiping Liu
- MOE Key Laboratory of Environmental Remediation & Ecosystem Health, Institute of Environmental Health, College of Environmental and Resource Sciences , Zhejiang University , Hangzhou 310058 , China
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17
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Chen H, Shen C, Chen Z, Ali BA, Wen Y. Dichlorprop induced structural changes of LHCⅡ chiral macroaggregates associated with enantioselective toxicity to Scnedesmus obliquus. Aquat Toxicol 2019; 206:54-60. [PMID: 30448745 DOI: 10.1016/j.aquatox.2018.11.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2018] [Revised: 11/03/2018] [Accepted: 11/04/2018] [Indexed: 06/09/2023]
Abstract
The enantioselective toxic mechanisms of chiral herbicides in photosynthetic organisms are closely related to the production of reactive oxygen species (ROS) production, however, there are few reports on how the enantioselective production of ROS can be triggered. In suboptimal conditions, photosynthesis is one of the most important processes in the production of ROS, especially in the process of light utilization and electron transfer. In this study, we investigated the interactions between chiral herbicide dichlorprop (DCPP) enantiomers and the chiral macroaggregates of the photosynthetic light-harvesting chlorophyll a/b pigment-protein complexes (LHCII) in Scenedesmus obliquus, which is of great significance in capturing and utilizing sun light, and also in dissipating the excess excitation energy. The results of the circular dichroism indicated that DCPP induced the structural changes of the LHCII chiral macroaggregates in an enantioselective manner and that the (R)-DCPP treated-group showed a bigger change accompanied by a changed enantioselective dissipation of the excitation energy. The excitation energy was excessed in DCPP treated-groups and the degree of excess was enantioselective and the detrimental non-chemical energy triggered the enantioselective production of ROS, that induced the enantioselective toxicity to green algae S. obliquus. Overall, this study has identified that how the enantioselective production of ROS can be triggered in chloroplasts; this can help to reveal the enantioselective mechanisms of chiral herbicides to photosynthetic organisms.
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Affiliation(s)
- Hui Chen
- College of Science and Technology, Ningbo University, Ningbo, 315211, China
| | - Chensi Shen
- College of Environmental Science and Engineering, Donghua University, Shanghai, 201620, China
| | - Zunwei Chen
- Department of Veterinary Integrative Biosciences, Texas A&M University, College Station, TX, 77843, United States
| | - Babar Aijaz Ali
- College of Environmental Science and Engineering, Donghua University, Shanghai, 201620, China
| | - Yuezhong Wen
- Institute of Environmental Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, 310058, China.
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18
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Nian Q, Ai L, Li D, Chen X, Zhang L, Wang M, Wang X. Rapid monitoring of plant growth regulators in bean sprouts via automated on-line polymeric monolith solid-phase extraction coupled with liquid chromatography tandem mass spectrometry. Anal Bioanal Chem 2018; 410:7239-7247. [PMID: 30151683 DOI: 10.1007/s00216-018-1334-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2018] [Revised: 08/15/2018] [Accepted: 08/17/2018] [Indexed: 12/17/2022]
Abstract
An automated on-line solid-phase extraction (SPE) following liquid chromatography tandem mass spectrometry was established for the fast determination of plant growth regulator residues in soybean sprout and mung bean sprout. The crude extracted specimens were directly purified on a poly (2-(dimethylamino) ethyl methacrylate-co-ethylene dimethacrylate) monolithic column which was well-defined as the on-line SPE adsorbent. Under the optimized conditions, the developed method gave the linear range of 0.3-50 ng/mL for gibberellin and 2,4-dichlorophenoxyacetic acid, 0.2-50 ng/mL for 4-chlorophenoxyacetic acid, and 0.5-50 ng/mL for 1-naphthaleneacetic acid (r ≥ 0.998). The detection limits (S/N = 3) ranged from 1.0 to 2.5 μg/kg and the recoveries for spiked soybean sprout samples were in the range of 75.0-93.3%. Besides, the total time for one analysis was 16 min. The reusability of the monolith was up to 600 extractions. The proposed process facilitated fully automated SPE and accurate determination in one step with rapidity, simplicity, and reliability. Graphical abstract ᅟ.
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Affiliation(s)
- Qixun Nian
- School of Public Health, North China University of Science and Technology, No. 21 Bohai Road, Caofeidian, Tangshan, 063210, Hebei, China
| | - Lianfeng Ai
- Hebei Entry-Exit Inspection and Quarantine Bureau, No. 318, Heping West Road, Shijiazhuang, 050000, Hebei, China
| | - Dongmei Li
- School of Public Health, North China University of Science and Technology, No. 21 Bohai Road, Caofeidian, Tangshan, 063210, Hebei, China
| | - Xuelei Chen
- School of Public Health, North China University of Science and Technology, No. 21 Bohai Road, Caofeidian, Tangshan, 063210, Hebei, China
| | - Lei Zhang
- School of Public Health, North China University of Science and Technology, No. 21 Bohai Road, Caofeidian, Tangshan, 063210, Hebei, China
| | - Manman Wang
- School of Public Health, North China University of Science and Technology, No. 21 Bohai Road, Caofeidian, Tangshan, 063210, Hebei, China.
| | - Xuesheng Wang
- School of Public Health, North China University of Science and Technology, No. 21 Bohai Road, Caofeidian, Tangshan, 063210, Hebei, China
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19
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Pozdnyakov I, Sherin P, Bazhin N, Plyusnin V. [Fe(Ox) 3] 3- complex as a photodegradation agent at neutral pH: Advances and limitations. Chemosphere 2018; 195:839-846. [PMID: 29289912 DOI: 10.1016/j.chemosphere.2017.12.096] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2017] [Revised: 11/24/2017] [Accepted: 12/15/2017] [Indexed: 06/07/2023]
Abstract
In the present work advances and limitations in the application of Fe(III)-oxalate complexes (namely, [Fe(Ox)3]3-) to the photodegradation of a model persistent organic contaminant - 2,4-dichlorophenoxybutanoic acid (2,4-DB) in neutral aqueous solutions were systematically investigated for the first time. It has been shown that the efficiency of [Fe(Ox)3]3- system greatly depends on the initial concentrations of oxalate ion due to the fast consumption of the ligand during photodegradation process leading to the formation of photochemically less active Fe(III) species. Efficiency of Fe(Ox)33- system normalized to UVA absorption at the excitation wavelength is practically independent on [Fe(III)]. Thus, it is highly probable that concentrations of Fe(III) as low as < 10-5 M could be applied in water treatment procedures using reactors with very long optical path. The system also keeps high efficiency at low concentration of pollutant (<10-5 M) though this results in higher relative consumption rate of Fe(III) and oxalate ions.
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Affiliation(s)
- Ivan Pozdnyakov
- V.V. Voevodsky Institute of Chemical Kinetics and Combustion, 3 Institutskaya str., 630090, Novosibirsk, Russian Federation; Novosibirsk State University, 2 Pirogova St., 630090, Novosibirsk, Russian Federation.
| | - Peter Sherin
- Novosibirsk State University, 2 Pirogova St., 630090, Novosibirsk, Russian Federation; International Tomography Center, 3a Institutskaya str., 630090, Novosibirsk, Russian Federation
| | - Nikolai Bazhin
- V.V. Voevodsky Institute of Chemical Kinetics and Combustion, 3 Institutskaya str., 630090, Novosibirsk, Russian Federation
| | - Victor Plyusnin
- V.V. Voevodsky Institute of Chemical Kinetics and Combustion, 3 Institutskaya str., 630090, Novosibirsk, Russian Federation; Novosibirsk State University, 2 Pirogova St., 630090, Novosibirsk, Russian Federation
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20
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Liu WC, Han TT, Yuan HM, Yu ZD, Zhang LY, Zhang BL, Zhai S, Zheng SQ, Lu YT. CATALASE2 functions for seedling postgerminative growth by scavenging H 2 O 2 and stimulating ACX2/3 activity in Arabidopsis. Plant Cell Environ 2017; 40:2720-2728. [PMID: 28722222 DOI: 10.1111/pce.13031] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2017] [Revised: 07/10/2017] [Accepted: 07/10/2017] [Indexed: 05/24/2023]
Abstract
Increased fatty acid β-oxidation is essential for early postgerminative growth in seedlings, but high levels of H2 O2 produced by β-oxidation can induce oxidative stress. Whether and how catalase (CAT) functions in fine-tuning H2 O2 homeostasis during seedling growth remain unclear. Here, we report that CAT2 functions in early seedling growth. Compared to the wild type, the cat2-1 mutant, with elevated H2 O2 levels, exhibited reduced root elongation on sucrose (Suc)-free medium, mimicking soils without exogenous sugar supply. Treatment with the H2 O2 scavenger potassium iodide rescued the mutant phenotype of cat2-1. In contrast to the wild type, the cat2-1 mutant was insensitive to the CAT inhibitor 3-amino-1,2,4-triazole in terms of root elongation when grown on Suc-free medium, suggesting that CAT2 modulates early seedling growth by altering H2 O2 accumulation. Furthermore, like cat2-1, the acyl-CoA oxidase (ACX) double mutant acx2-1 acx3-6 showed repressed root elongation, suggesting that CAT2 functions in early seedling growth by regulating ACX activity, as this activity was inhibited in cat2-1. Indeed, decreased ACX activity and short root of cat2-1 seedlings grown on Suc-free medium were rescued by overexpressing ACX3. Together, these findings suggest that CAT2 functions in early seedling growth by scavenging H2 O2 and stimulating ACX2/3 activity.
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Affiliation(s)
- Wen-Cheng Liu
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan, 430072, China
| | - Tong-Tong Han
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan, 430072, China
| | - Hong-Mei Yuan
- Hainan Key Laboratory for Sustainable Utilization of Tropical Bioresources, College of Agriculture, Hainan University, Haikou, 570228, China
| | - Zhen-Dong Yu
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan, 430072, China
| | - Lin-Yu Zhang
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan, 430072, China
| | - Bing-Lei Zhang
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan, 430072, China
| | - Shuang Zhai
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan, 430072, China
| | - Si-Qiu Zheng
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan, 430072, China
| | - Ying-Tang Lu
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan, 430072, China
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21
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Chen Z, Wang J, Chen H, Wen Y, Liu W. Enantioselective Phytotoxicity of Dichlorprop to Arabidopsis thaliana: The Effect of Cytochrome P450 Enzymes and the Role of Fe. Environ Sci Technol 2017; 51:12007-12015. [PMID: 28906105 DOI: 10.1021/acs.est.7b04252] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The ecotoxicology effects of chiral herbicides have long been recognized and have drawn increasing attention. The toxic mechanisms of herbicides in plants are involved in production of reactive oxygen species (ROS) and cause damage to target enzymes, but the relationship between these two factors in the enantioselectivity of chiral herbicides has rarely been investigated. Furthermore, even though cytochromes P450 enzymes (CYP450s) have been related to the phytotoxicity of herbicides, their roles in the enantioselectivity of chiral herbicides have yet to be explored. To solve this puzzle, the CYP450s suicide inhibitor 1-aminobenzotriazole (ABT) was added to an exposure system made from dichlorprop (DCPP) enantiomers in the model plant Arabidopsis thaliana. The results indicated that different phytotoxicities of DCPP enantiomers by causing oxidative stress and acetyl-CoA carboxylase (ACCase) damage were observed in the presence and the absence of ABT. The addition of ABT decreased the toxicity of (R)-DCPP but was not significantly affected that of (S)-DCPP, resulting in smaller differences between enantiomers. Furthermore, profound differences were also observed in Fe uptake and distribution, exhibiting different distribution patterns in A. thaliana leaves exposed to DCPP and ABT, which helped bridge the relationship between ROS production and target enzyme ACCase damage through the function of CYP450s. These results offer an opportunity for a more-comprehensive understanding of chiral herbicide action mechanism and provide basic evidence for risk assessments of chiral herbicides in the environment.
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Affiliation(s)
- Zunwei Chen
- MOE Key Laboratory of Environmental Remediation & Ecosystem Health, College of Environmental and Resource Sciences, Zhejiang University , Hangzhou 310058, China
- Department of Veterinary Integrative Bioscience, Texas A&M University , College Station, Texas 77843, United States
| | - Jia Wang
- MOE Key Laboratory of Environmental Remediation & Ecosystem Health, College of Environmental and Resource Sciences, Zhejiang University , Hangzhou 310058, China
| | - Hui Chen
- MOE Key Laboratory of Environmental Remediation & Ecosystem Health, College of Environmental and Resource Sciences, Zhejiang University , Hangzhou 310058, China
| | - Yuezhong Wen
- MOE Key Laboratory of Environmental Remediation & Ecosystem Health, College of Environmental and Resource Sciences, Zhejiang University , Hangzhou 310058, China
| | - Weiping Liu
- MOE Key Laboratory of Environmental Remediation & Ecosystem Health, College of Environmental and Resource Sciences, Zhejiang University , Hangzhou 310058, China
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Yuan W, Liu Z, Liu P, Zhao R, Wu G, Fan S, Zhou Y. [Determination of 4 kinds of plant growth regulator in bean sprout by solid phase extraction column coupled with ultra-high performance liquid chromatography]. Wei Sheng Yan Jiu 2017; 46:783-812. [PMID: 29903308] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
OBJECTIVE A method for the determination of 6-benzylaminopurine( 6-BAP), isopentennyladenine( z-IP), 4-fluorophenoxyacetic acid( 4-FPA), 4-chlorophenoxyacetic acid( 4-CPA) in bean sprout was developed using solid phase extraction column with ultra-high performance liquid chromatography. METHODS The sample was extracted by acetonitrile,dehydrated by salt,then centrifugation,and purified by PXC/PWA solid phase extraction column. The chromatographic analysis was carried out on C18 chromatographic column( 100 mm ×2. 1 mm,1. 8 μm),acetonitrile and sodium dihydrogen phosphate for gradient elution,diode array detector for detection,and quantified with external standard method. RESULTS The calibration curves showed good linearity in the range of 0. 25-25 μg/mL( 6-BAP and z-IP) and 0. 50-50 μg/mL( 4-FPA and 4-CPA) with correlation coefficients greater than 0. 999. Three levels spiked recoveries were carried out using blank bean sprout extraction as substrate,the recoveries ranged from70. 0% to 96. 4%,and the relative standard deviations( RSDs) ranged from 2. 84% to12. 10%( n = 6). The qualitative limits of detections were 0. 0082-0. 075 mg/kg and the quantitative limits were 0. 027-0. 25 mg/kg for the 4 PGRs. CONCLUSION The method is simple and easy to operate using solid phase extraction column coupled,simultaneous determination of 4 PGRs by ultra-high performance liquid chromatography,can ensure the corresponding accuracy,sensitivity and precision.
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Affiliation(s)
- Wenxin Yuan
- Pinggu District Center for Disease Control and Prevention, Beijing 101200, China
| | - Zhiping Liu
- Pinggu District Center for Disease Control and Prevention, Beijing 101200, China
| | | | - Rong Zhao
- Pinggu District Center for Disease Control and Prevention, Beijing 101200, China
| | - Guohua Wu
- Pinggu District Center for Disease Control and Prevention, Beijing 101200, China
| | - Sai Fan
- Pinggu District Center for Disease Control and Prevention, Beijing 101200, China
| | - Yang Zhou
- Pinggu District Center for Disease Control and Prevention, Beijing 101200, China
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Han Y, Yang C, Zhou Y, Han D, Yan H. Ionic Liquid-Hybrid Molecularly Imprinted Material-Filter Solid-Phase Extraction Coupled with HPLC for Determination of 6-Benzyladenine and 4-Chlorophenoxyacetic Acid in Bean Sprouts. J Agric Food Chem 2017; 65:1750-1757. [PMID: 28147482 DOI: 10.1021/acs.jafc.6b03922] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
A new method involving ionic liquid-hybrid molecularly imprinted material-filter solid-phase extraction coupled to high-performance liquid chromatography (IL-HIM-FSPE-HPLC) was developed for the simultaneous isolation and determination of 6-benzyladenine (6-BA) and 4-chlorophenoxyacetic acid (4-CPA) in bean sprouts. Sample preconcentration was performed using a modified filter, with the new IL-HIM as the adsorbent, which shows double adsorption. The first adsorption involves special recognition of molecular imprinting, and the second involves ion exchange and electrostatic attraction caused by the ionic liquid. This method combines the advantages of ionic liquids, hybrid materials, and molecularly imprinted polymers and was successfully applied to determine 6-BA and 4-CPA in bean sprouts. The adsorption of 6-BA to IL-HIM is based on selective imprinted recognition, whereas the adsorption of 4-CPA is mainly dependent on ion-exchange interactions.
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Affiliation(s)
- Yehong Han
- Key Laboratory of Medicinal Chemistry and Molecular Diagnosis, College of Public Health, and ‡Key Laboratory of Analytical Science and Technology of Hebei Province & College of Chemistry and Environmental Science, Hebei University , Baoding 071002, China
| | - Chunliu Yang
- Key Laboratory of Medicinal Chemistry and Molecular Diagnosis, College of Public Health, and ‡Key Laboratory of Analytical Science and Technology of Hebei Province & College of Chemistry and Environmental Science, Hebei University , Baoding 071002, China
| | - Yang Zhou
- Key Laboratory of Medicinal Chemistry and Molecular Diagnosis, College of Public Health, and ‡Key Laboratory of Analytical Science and Technology of Hebei Province & College of Chemistry and Environmental Science, Hebei University , Baoding 071002, China
| | - Dandan Han
- Key Laboratory of Medicinal Chemistry and Molecular Diagnosis, College of Public Health, and ‡Key Laboratory of Analytical Science and Technology of Hebei Province & College of Chemistry and Environmental Science, Hebei University , Baoding 071002, China
| | - Hongyuan Yan
- Key Laboratory of Medicinal Chemistry and Molecular Diagnosis, College of Public Health, and ‡Key Laboratory of Analytical Science and Technology of Hebei Province & College of Chemistry and Environmental Science, Hebei University , Baoding 071002, China
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Torun M, Şolpan D. Analytical studies on degradation mechanism of herbicide 4-chlorophenoxyacetic acid in water by gamma/H2O2 and gamma/ozone processes. Environ Technol 2016; 37:2494-2507. [PMID: 26878254 DOI: 10.1080/09593330.2016.1153155] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2015] [Accepted: 02/08/2016] [Indexed: 06/05/2023]
Abstract
Radiolytic degradation of 4-chlorophenoxyacetic acid was followed in the presence of hydrogen peroxide and ozone. The synergic effect of ozone is found to be relatively high since the amounts of detected aromatic intermediates are lower as well as the amounts of small aliphatic acids are higher. Chloride ions are one of the most important mineralization products and splitted with a yield of more than 80%. The amounts of small aliphatic acids formed in the last step before mineralization (oxalic, acetic and formic acid) were followed and their formation from 4-chlorophenoxyacetic acid was confirmed. Dissolved oxygen was consumed to form reactive radicals during irradiation. Product analysis and confirmation are followed by gas chromatography/mass spectrometry and ion chromatography. The degradation path of 4-chlorophenoxyacetic acid was suggested with determined intermediates.
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Affiliation(s)
- Murat Torun
- a Department of Chemistry , Hacettepe University , Beytepe-Ankara , Turkey
| | - Dilek Şolpan
- a Department of Chemistry , Hacettepe University , Beytepe-Ankara , Turkey
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Chen Z, Chen H, Zou Y, Wen Y. Stomatal behaviors reflect enantioselective phytotoxicity of chiral herbicide dichlorprop in Arabidopsis thaliana. Sci Total Environ 2016; 562:73-80. [PMID: 27092421 DOI: 10.1016/j.scitotenv.2016.03.205] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2016] [Revised: 03/27/2016] [Accepted: 03/27/2016] [Indexed: 06/05/2023]
Abstract
Stomata in plants play vital roles in water transpiration and gas exchange necessary for photosynthesis, which are critical for the plants growth. Until now, however, the effect of chiral herbicides on the response of stomata was poorly understood. To unveil this puzzle, the enantioselective effect of chiral herbicide dichloroprop (DCPP) on stomata in Arabidopsis thaliana was investigated. It was found that (R)-DCPP preferentially promoted the extent of stomatal opening in Arabidopsis leaves, resulting in 59.84% enhancement at 0.3μmol·L(-1) comparing to the control, where (S)- and (Rac)-DCPP exhibited no significant differences. Enantioselectivity was also observed in the response of stomata to DCPP. To better understand the mechanism involved, the reactive oxygen species (ROS) production and antioxidant system defense were measured. Interestingly, the ROS production in Arabidopsis leaves was also enantioselective. The (R)-DCPP treatments resulted in 6.08-fold enhancement compared with the control, whereas 1.35- and 2.51-fold increases occurred in (S)-DCPP and (Rac)-DCPP treatments, respectively. The promoting of stomatal opening was positively correlated with ROS production. In addition, the antioxidant system response provided evidence of oxidative stress and damage caused by DCPP. This study confirmed that the ROS produced by DCPP promoted stomatal opening and suggested a potential sight to elucidate the phytotoxicity of chiral herbicides.
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Affiliation(s)
- Zunwei Chen
- MOE Key Laboratory of Environmental Remediation & Ecosystem Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China
| | - Hui Chen
- MOE Key Laboratory of Environmental Remediation & Ecosystem Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China
| | - Yuqin Zou
- MOE Key Laboratory of Environmental Remediation & Ecosystem Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China
| | - Yuezhong Wen
- MOE Key Laboratory of Environmental Remediation & Ecosystem Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China.
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Liu P, Fan S, Wu G, Zhao R, Liu W, Zhao X. [Determination of 6 kinds of plant growth regulator in bean sprout by ultra high performance liquid chromatography-tandem mass spectrometry]. Wei Sheng Yan Jiu 2016; 45:483-489. [PMID: 27459816] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
OBJECTIVE A method for the simultaneous determination of 6 plant growth regulator (PGR) residues in bean sprout was developed by ultra high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). 6-Benzylaminopurine, isopentennyladenine, 4-chlorophenoxyacetic acid, 4-fluorophenoxyacetic acid, indole-3- acetic acid and indole-3-butyric acid were concerned. METHODS Bean sprout samples were extracted by acetonitrile and QuEChERS extraction kit, purified by C18 powers. After centrifugation, the sample liquids was diluted 10 times by ultrapure water. The chromatographic analysis was carried out on an waters acquity UPLC BEH C18 column( 100 mm x 2.1 mm, 1.7 microm). The analyzer confirmed and quantified by mass spectrum of triple quadrupole in the multiple reaction monitoring (MRM) mode and quantified by matrix-matched external standard method. RESULTS The calibration curves showed good linearity in each range with correlation coefficients greater than 0.998. 3 levels spiked recoveries were carried out using blank bean sprout extraction as substrate, the recoveries ranged from 84.2% to 107.5%, the relative standard deviations (RSDs) ranged from 3.08% to 12.71%. The qualitative limits of detections (S/N = 3) were 0.03-3.0 microg/kg and the quantitative limits(S/N = 10) were 0.1-10.0 microg/kg for the 6 PGRs. CONSLUSION The method is simple and easy to operate, with less organic reagent, high sensitivity and good stability. It is suitable for the detection of 6 kinds of plant growth regulators in bean sprouts.
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Abstract
Approaches based on the octanol-water partition coefficient are commonly used to describe sorption of neutral organic compounds in environmental systems, but they are not suitable for organic acids, which can dissociate to form anions. We here investigate the applicability of an alternative approach based on the pH-dependent distribution ratio (DOW) to describe sorption of aromatic acids to sorbents representing different degrees of carbonization. Sorption isotherms for four structurally similar acids ((2,4-dichlorophenoxy)acetic acid (2,4-D), 4-chloro-2-15 methylphenoxy)acetic acid (MCPA), 4-(2,4-dichlorophenoxy)butanoic16 acid (2,4-DB), and 5-chloro-2-(2,4-dichlorophenoxy)phenol (triclosan)) were measured for 15 sorbents: fresh and carbonized wood shavings, pig manure, sewage sludge, carbon nanotubes, and activated carbon. Dissociation greatly affected the sorption of all acids. Sorption coefficients measured in the high pH range indicated that sorption of the anions ranged over several orders of magnitude and should not be neglected. Sorption trends for all sorbates and carbonized sorbents could be very well described by a single regression equation that included DOW of the sorbate and the specific surface area of the sorbent (R(2) > 0.89).
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Affiliation(s)
- Gabriel Sigmund
- Department of Environmental Geosciences, University of Vienna , Althanstrasse 14 UZA II, 1090 Vienna, Austria
| | - Huichao Sun
- Department of Environmental Geosciences, University of Vienna , Althanstrasse 14 UZA II, 1090 Vienna, Austria
| | - Thilo Hofmann
- Department of Environmental Geosciences, University of Vienna , Althanstrasse 14 UZA II, 1090 Vienna, Austria
| | - Melanie Kah
- Department of Environmental Geosciences, University of Vienna , Althanstrasse 14 UZA II, 1090 Vienna, Austria
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28
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Pozdnyakov I, Sherin P, Grivin V, Plyusnin V. Degradation of herbicide 2,4-dichlorophenoxybutanoic acid in the photolysis of [FeOH]2+ and [Fe(Ox)3]3- complexes: A mechanistic study. Chemosphere 2016; 146:280-288. [PMID: 26735728 DOI: 10.1016/j.chemosphere.2015.12.041] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2015] [Revised: 12/08/2015] [Accepted: 12/11/2015] [Indexed: 06/05/2023]
Abstract
In the present work the Fe(III)-assisted photodegradation of the herbicide 2,4-dichlorophenoxybutanoic acid (2,4-DB) has been studied by means of stationary (308 nm) and laser flash (355 nm) photolysis. The initial quantum yield of 2,4-DB photodegradation in [FeOH](2+) and [Fe(Ox)3](3-) systems was evaluated to be 0.11 and 0.17 upon 308 nm exposure, respectively. The prolonged photolysis of [FeOH](2+) and [Fe(Ox)3](3-) systems results in the complete degradation of 2,4-DB with almost complete mineralization of herbicide and its aromatic products in the case of [FeOH](2+) photolysis and the accumulation of some persistent aromatic products in the case of [Fe(Ox)3](3-) photolysis. For both systems the main primary products of 2,4-DB photolysis determined by liquid chromatography - mass spectrometry are products of the hydroxylation, the substitution of chlorine atom to OH group, the loss of aliphatic tail and the opening of benzene ring. The obtained results indicate ROS species (mainly OH radical) to be responsible for the herbicide photodegradation.
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Affiliation(s)
- Ivan Pozdnyakov
- V.V. Voevodsky Institute of Chemical Kinetics and Combustion, 3 Institutskaya str., 630090, Novosibirsk, Russian Federation; Novosibirsk State University, 2 Pirogova St., 630090, Novosibirsk, Russian Federation.
| | - Peter Sherin
- Novosibirsk State University, 2 Pirogova St., 630090, Novosibirsk, Russian Federation; International Tomography Center, 3a Institutskaya str., 630090, Novosibirsk, Russian Federation
| | - Vjacheslav Grivin
- V.V. Voevodsky Institute of Chemical Kinetics and Combustion, 3 Institutskaya str., 630090, Novosibirsk, Russian Federation
| | - Victor Plyusnin
- V.V. Voevodsky Institute of Chemical Kinetics and Combustion, 3 Institutskaya str., 630090, Novosibirsk, Russian Federation; Novosibirsk State University, 2 Pirogova St., 630090, Novosibirsk, Russian Federation
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Feld L, Nielsen TK, Hansen LH, Aamand J, Albers CN. Establishment of Bacterial Herbicide Degraders in a Rapid Sand Filter for Bioremediation of Phenoxypropionate-Polluted Groundwater. Appl Environ Microbiol 2016; 82:878-887. [PMID: 26590282 DOI: 10.1128/aem.02600-15.editor] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2015] [Accepted: 11/16/2015] [Indexed: 05/24/2023] Open
Abstract
In this study, we investigated the establishment of natural bacterial degraders in a sand filter treating groundwater contaminated with the phenoxypropionate herbicides (RS)-2-(4-chloro-2-methylphenoxy)propanoic acid (MCPP) and (RS)-2-(2,4-dichlorophenoxy)propanoic acid (DCPP) and the associated impurity/catabolite 4-chlorophenoxypropanoic acid (4-CPP). A pilot facility was set up in a contaminated landfill site. Anaerobic groundwater was pumped up and passed through an aeration basin and subsequently through a rapid sand filter, which is characterized by a short residence time of the water in the filter. For 3 months, the degradation of DCPP, MCPP, and 4-CPP in the sand filter increased to 15 to 30% of the inlet concentration. A significant selection for natural bacterial herbicide degraders also occurred in the sand filter. Using a most-probable-number (MPN) method, we found a steady increase in the number of culturable phenoxypropionate degraders, reaching approximately 5 × 10(5) degraders per g sand by the end of the study. Using a quantitative PCR targeting the two phenoxypropionate degradation genes, rdpA and sdpA, encoding stereospecific dioxygenases, a parallel increase was observed, but with the gene copy numbers being about 2 to 3 log units higher than the MPN. In general, the sdpA gene was more abundant than the rdpA gene, and the establishment of a significant population of bacteria harboring sdpA occurred faster than the establishment of an rdpA gene-carrying population. The identities of the specific herbicide degraders in the sand filter were assessed by Illumina MiSeq sequencing of 16S rRNA genes from sand filter samples and from selected MPN plate wells. We propose a list of potential degrader bacteria involved in herbicide degradation, including representatives belonging to the Comamonadaceae and Sphingomonadales.
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Affiliation(s)
- Louise Feld
- Department of Geochemistry, Geological Survey of Denmark & Greenland, Copenhagen, Denmark
| | | | | | - Jens Aamand
- Department of Geochemistry, Geological Survey of Denmark & Greenland, Copenhagen, Denmark
| | - Christian Nyrop Albers
- Department of Geochemistry, Geological Survey of Denmark & Greenland, Copenhagen, Denmark
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Kerchev P, Mühlenbock P, Denecker J, Morreel K, Hoeberichts FA, Van Der Kelen K, Vandorpe M, Nguyen L, Audenaert D, Van Breusegem F. Activation of auxin signalling counteracts photorespiratory H2O2-dependent cell death. Plant Cell Environ 2015; 38:253-265. [PMID: 26317137 DOI: 10.1111/pce.12250] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The high metabolic flux through photorespiration constitutes a significant part of the carbon cycle. Although the major enzymatic steps of the photorespiratory pathway are well characterized, little information is available on the functional significance of photorespiration beyond carbon recycling. Particularly important in this respect is the peroxisomal catalase activity which removes photorespiratory H2O2 generated during the oxidation of glycolate to glyoxylate, thus maintaining the cellular redox homeostasis governing the perception, integration and execution of stress responses. By performing a chemical screen, we identified 34 small molecules that alleviate the negative effects of photorespiration in Arabidopsis thaliana mutants lacking photorespiratory catalase (cat2). The chlorophyll fluorescence parameter photosystem II maximum efficiency (Fv′/Fm′) was used as a high-throughput readout. The most potent chemical that could rescue the photorespiratory phenotype of cat2 is a pro-auxin that contains a synthetic auxin-like substructure belonging to the phenoxy herbicide family, which can be released in planta. The naturally occurring indole-3-acetic acid (IAA) and other chemically distinct synthetic auxins also inhibited the photorespiratory-dependent cell death in cat2 mutants, implying a role for auxin signalling in stress tolerance.
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Sannino F, Pernice P, Minieri L, Camandona GA, Aronne A, Pirozzi D. Oxidative degradation of different chlorinated phenoxyalkanoic acid herbicides by a hybrid ZrO2 gel-derived catalyst without light irradiation. ACS Appl Mater Interfaces 2015; 7:256-263. [PMID: 25479367 DOI: 10.1021/am506031e] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The oxidative degradation of 2-methyl-4-chlorophenoxyacetic acid (MCPA), 4-(4-chloro-2-methylphenoxy)butanoic acid (MCPB), 4-chlorophenoxyacetic acid (4-CPA) and 2,4-dichlorophenoxyacetic acid (2,4 D) by ZrO2-acetylacetonate hybrid catalyst (HSGZ) without light irradiation was assessed. The thermal stability of the catalyst was investigated by thermogravimetry, differential thermal analysis, and Fourier transform infrared spectroscopy. For each herbicide, a virtually complete removal in about 3 days without light irradiation at room temperature was achieved. The removal kinetics of the herbicides has been satisfactorily characterized by a double-stage physico-mathematical model, in the hypothesis that a first-order adsorption on HSGZ surface is followed by the herbicide degradation, catalytically driven by HSGZ surface groups. The long-term use of the HSGZ catalyst was assessed by repeated-batch tests. The specific cost for unit-volume removal of herbicide was evaluated by a detailed cost analysis showing that it is comparable with those pertaining to alternative methods.
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Affiliation(s)
- Filomena Sannino
- Dipartimento di Agraria and §Centro Interdipartimentale di Ricerca sulla Risonanza Magnetica Nucleare per l'Ambiente, l'Agro-Alimentare ed i Nuovi Materiali (CERMANU) Università di Napoli Federico II , Via Università 100, 80055 Portici (Napoli), Italy
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Cassin-Ross G, Hu J. Systematic phenotypic screen of Arabidopsis peroxisomal mutants identifies proteins involved in β-oxidation. Plant Physiol 2014; 166:1546-59. [PMID: 25253886 PMCID: PMC4226370 DOI: 10.1104/pp.114.250183] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Peroxisomes are highly dynamic and multifunctional organelles essential to development. Plant peroxisomes accommodate a multitude of metabolic reactions, many of which are related to the β-oxidation of fatty acids or fatty acid-related metabolites. Recently, several dozens of novel peroxisomal proteins have been identified from Arabidopsis (Arabidopsis thaliana) through in silico and experimental proteomic analyses followed by in vivo protein targeting validations. To determine the functions of these proteins, we interrogated their transfer DNA insertion mutants with a series of physiological, cytological, and biochemical assays to reveal peroxisomal deficiencies. Sugar dependence and 2,4-dichlorophenoxybutyric acid and 12-oxo-phytodienoic acid response assays uncovered statistically significant phenotypes in β-oxidation-related processes in mutants for 20 of 27 genes tested. Additional investigations uncovered a subset of these mutants with abnormal seed germination, accumulation of oil bodies, and delayed degradation of long-chain fatty acids during early seedling development. Mutants for seven genes exhibited deficiencies in multiple assays, strongly suggesting the involvement of their gene products in peroxisomal β-oxidation and initial seedling growth. Proteins identified included isoforms of enzymes related to β-oxidation, such as acyl-CoA thioesterase2, acyl-activating enzyme isoform1, and acyl-activating enzyme isoform5, and proteins with functions previously unknown to be associated with β-oxidation, such as Indigoidine synthase A, Senescence-associated protein/B12D-related protein1, Betaine aldehyde dehydrogenase, and Unknown protein5. This multipronged phenotypic screen allowed us to reveal β-oxidation proteins that have not been discovered by single assay-based mutant screens and enabled the functional dissection of different isoforms of multigene families involved in β-oxidation.
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Affiliation(s)
- Gaëlle Cassin-Ross
- Michigan State University-Department of Energy Plant Research Laboratory (G.C.-R., J.H.) andPlant Biology Department (J.H.), Michigan State University, East Lansing, Michigan 48824
| | - Jianping Hu
- Michigan State University-Department of Energy Plant Research Laboratory (G.C.-R., J.H.) andPlant Biology Department (J.H.), Michigan State University, East Lansing, Michigan 48824
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Gowdra VS, Mudgal J, Bansal P, Nayak PG, Manohara Reddy SA, Shenoy GG, Valiathan M, Chamallamudi MR, Nampurath GK. Synthesis, characterization, and preclinical evaluation of new thiazolidin-4-ones substituted with p-chlorophenoxy acetic acid and clofibric acid against insulin resistance and metabolic disorder. Biomed Res Int 2014; 2014:620434. [PMID: 24995315 PMCID: PMC4065710 DOI: 10.1155/2014/620434] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/28/2014] [Revised: 05/03/2014] [Accepted: 05/06/2014] [Indexed: 11/18/2022]
Abstract
We synthesized twenty thiazolidin-4-one derivatives, which were then characterized by standard chromatographic and spectroscopic methods. From the in vitro glucose uptake assay, two compounds behaved as insulin sensitizers, where they enhanced glucose uptake in isolated rat diaphragm. In high-carbohydrate diet-induced insulin resistant mice, these two thiazolidin-4-ones attenuated hyperglycemia, hyperinsulinemia, hypertriglyceridemia, hypercholesterolemia, and glucose intolerance. They raised the plasma leptin but did not reverse the diabetes-induced hypoadiponectinemia. Additionally, compound 3a reduced adiposity. The test compounds were also able to reverse the disturbed liver antioxidant milieu. To conclude, these two novel thiazolidin-4-ones modulated multiple mechanisms involved in metabolic disorders, reversing insulin resistance and thus preventing the development of type-2 diabetes.
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Affiliation(s)
- Vasantharaju S. Gowdra
- Department of Pharmaceutical Quality Assurance, Manipal College of Pharmaceutical Sciences, Manipal University, Manipal, Karnataka 576104, India
| | - Jayesh Mudgal
- Department of Pharmacology, Manipal College of Pharmaceutical Sciences, Manipal University, Manipal, Karnataka 576104, India
| | - Punit Bansal
- Department of Pharmacology, Manipal College of Pharmaceutical Sciences, Manipal University, Manipal, Karnataka 576104, India
| | - Pawan G. Nayak
- Department of Pharmacology, Manipal College of Pharmaceutical Sciences, Manipal University, Manipal, Karnataka 576104, India
| | - Seethappa A. Manohara Reddy
- Department of Pharmacology, Manipal College of Pharmaceutical Sciences, Manipal University, Manipal, Karnataka 576104, India
| | - Gautham G. Shenoy
- Department of Pharmaceutical Chemistry, Manipal College of Pharmaceutical Sciences, Manipal University, Manipal, Karnataka 576104, India
| | - Manna Valiathan
- Department of Pathology, Kasturba Medical College, Manipal University, Manipal, Karnataka 576104, India
| | - Mallikarjuna R. Chamallamudi
- Department of Pharmacology, Manipal College of Pharmaceutical Sciences, Manipal University, Manipal, Karnataka 576104, India
| | - Gopalan K. Nampurath
- Department of Pharmacology, Manipal College of Pharmaceutical Sciences, Manipal University, Manipal, Karnataka 576104, India
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Tunç S, Duman O, Soylu I, Kancı Bozoğlan B. Study on the bindings of dichlorprop and diquat dibromide herbicides to human serum albumin by spectroscopic methods. J Hazard Mater 2014; 273:36-43. [PMID: 24709480 DOI: 10.1016/j.jhazmat.2014.03.022] [Citation(s) in RCA: 82] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/27/2013] [Revised: 03/10/2014] [Accepted: 03/11/2014] [Indexed: 06/03/2023]
Abstract
The interactions of dichlorprop (DCP) and diquat dibromide (DQ) herbicides with human serum albumin (HSA) protein were studied by UV absorption, fluorescence, synchronous fluorescence and circular dichroism (CD) spectroscopy. Both DCP and DQ quenched the fluorescence emission spectrum of HSA through the static quenching mechanism. The Stern-Volmer quenching constant, binding constant, the number of binding sites and thermodynamic parameters were determined at 288K, 298K, 310K and 318K. In HSA-DCP and HSA-DQ systems, an increase in temperature led to a decrease in the Stern-Volmer quenching constant and binding constant. One binding site was obtained for DCP and DQ on HSA. It was found that DCP can bind to HSA with higher affinity than DQ. Negative ΔH and positive ΔS values were obtained for the binding processes between protein and herbicide molecules. This result displayed that electrostatic interactions play a major role in the formation of HSA-DCP and HSA-DQ complexes. The binding processes were exothermic reactions and spontaneous. In addition, synchronous fluorescence and CD spectra of HSA revealed that the binding of DCP to HSA did not cause a significant conformational change in protein, but the interaction of DQ with HSA led to an alteration in the protein structure.
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Affiliation(s)
- Sibel Tunç
- Akdeniz University, Faculty of Science, Department of Chemistry, 07058 Antalya, Turkey.
| | - Osman Duman
- Akdeniz University, Faculty of Science, Department of Chemistry, 07058 Antalya, Turkey.
| | - Inanç Soylu
- Akdeniz University, Faculty of Science, Department of Chemistry, 07058 Antalya, Turkey
| | - Bahar Kancı Bozoğlan
- Akdeniz University, Faculty of Science, Department of Chemistry, 07058 Antalya, Turkey
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Levi S, Hybel AM, Bjerg PL, Albrechtsen HJ. Stimulation of aerobic degradation of bentazone, mecoprop and dichlorprop by oxygen addition to aquifer sediment. Sci Total Environ 2014; 473-474:667-75. [PMID: 24412734 DOI: 10.1016/j.scitotenv.2013.12.061] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2013] [Revised: 12/12/2013] [Accepted: 12/12/2013] [Indexed: 05/23/2023]
Abstract
In order to investigate aerobic degradation potential for the herbicides bentazone, mecoprop and dichlorprop, anaerobic groundwater samples from two monitoring and three drinking water wells near a drinking water abstraction field in Nybølle, Denmark, were screened for their degradation potential for the herbicides. In the presence of oxygen (14)C-labelled bentazone and mecoprop were removed significantly from the two monitoring wells' groundwater samples. Oxygen was added to microcosms in order to investigate whether different oxygen concentrations stimulate the biodegradation of the three herbicides in microcosms using groundwater and sandy aquifer materials. To maintain a certain oxygen concentration this level was measured from the outside of the bottles with a fibre oxygen meter using oxygen-sensitive luminescent sensor foil mounted inside the microcosm, to which supplementary oxygen was added. The highest oxygen concentrations (corresponding to 4-11 mg L(-1)) stimulated degradation (a 14-27% increase for mecoprop, 3-9% for dichlorprop and 15-20% for bentazone) over an experimental period of 200 days. Oxygen was required to biodegrade the herbicides, since no degradation was observed under anaerobic conditions. This is the first time bentazone degradation has been observed in aquifer material at low oxygen concentrations (2 mg L(-1)). The sediment had substantial oxygen consumption (0.92-1.45O2 g(-1)dw over 200 days) and oxygen was depleted rapidly in most incubations soon after its addition, which might be due to the oxidation of organic matter and other reduced species such as Fe(2+), S(2-) and Mn in sediment before the biodegradation of herbicides takes place. This study suggests that oxygen enhancement around a drinking water abstraction field could stimulate the bioremediation of diffuse source contamination.
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Affiliation(s)
- S Levi
- Technical University of Denmark, DTU Environment, Department of Environmental Engineering, Miljoevej 113, 2800 Kongens Lyngby, Denmark
| | - A-M Hybel
- Technical University of Denmark, DTU Environment, Department of Environmental Engineering, Miljoevej 113, 2800 Kongens Lyngby, Denmark
| | - P L Bjerg
- Technical University of Denmark, DTU Environment, Department of Environmental Engineering, Miljoevej 113, 2800 Kongens Lyngby, Denmark
| | - H-J Albrechtsen
- Technical University of Denmark, DTU Environment, Department of Environmental Engineering, Miljoevej 113, 2800 Kongens Lyngby, Denmark.
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36
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Liu W, Li H, Tao F, Li S, Tian Z, Xie H. Formation and contamination of PCDD/Fs, PCBs, PeCBz, HxCBz and polychlorophenols in the production of 2,4-D products. Chemosphere 2013; 92:304-308. [PMID: 23601123 DOI: 10.1016/j.chemosphere.2013.03.031] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2012] [Revised: 03/05/2013] [Accepted: 03/16/2013] [Indexed: 06/02/2023]
Abstract
The concentrations and profiles of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), polychlorinated biphenyls (PCBs), pentachlorobenzene (PeCBz), hexachlorobenzene (HxCBz) and polychlorophenols in 2,4-D were investigated in this study. Two 2,4-D acid and three 2,4-D butyl ester enterprises were selected as typical 2,4-D producers. The total concentrations of 2,3,7,8-PCDD/Fs in the 2,4-D samples ranged from 355 to 35080ngkg(-1) and the corresponding TEQ values were in the range of 13.4 and 694.6ng WHO-TEQkg(-1). The concentrations of total PCBs in the 2,4-D were in the range of 16.1 and 8023ngkg(-1), and the WHO-TEQ values of the PCBs were between 0.057 and 108.3ng WHO-TEQkg(-1), while total PCBs were between 1486 and 47342ngkg(-1). The average emission factors were 414.4μg WHO-TEQt(-1) for PCDD/Fs and 21.9μg WHO-TEQt(-1) for PCBs. The polychlorobenzenes and polychlorophenols impurities may play a key role in the PCBs and PCDD/Fs formation. The impurities of PCDD/Fs and PCBs in 2,4-D may increase the risk for the human and environmental health.
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Affiliation(s)
- Wenbin Liu
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, Beijing 100085, China.
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37
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Milosevic N, Qiu S, Elsner M, Einsiedl F, Maier MP, Bensch HKV, Albrechtsen HJ, Bjerg PL. Combined isotope and enantiomer analysis to assess the fate of phenoxy acids in a heterogeneous geologic setting at an old landfill. Water Res 2013; 47:637-649. [PMID: 23168311 DOI: 10.1016/j.watres.2012.10.029] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2012] [Revised: 09/20/2012] [Accepted: 10/14/2012] [Indexed: 06/01/2023]
Abstract
Phenoxy acid herbicides and their potential metabolites represent industrial or agricultural waste that impacts groundwater and surface waters through leaching from old landfills throughout the world. Fate assessment of dichlorprop and its putative metabolite 4-CPP (2-(4-chlorophenoxy)propionic acid) is frequently obstructed by inconclusive evidence from redox conditions, heterogeneous geologic settings (e.g. clay till) and ambiguous parent-daughter relationships (i.e. 4-CPP may be daughter product or impurity of dichlorprop). For the first time, a combination of four methods was tested to assess transformation of phenoxy acids at a contaminated landfill (Risby site): analysis of (i) parent and daughter compound concentrations, (ii) enantiomer ratios (iii) compound-specific isotope analysis and (iv) enantiomer-specific isotope analysis. Additionally, water isotopes and chloride were used as conservative tracers to delineate two distinct groundwater flow paths in the clay till. Metabolite concentrations and isotope ratios of chlorinated ethenes demonstrated dechlorination activity in the area with highest leachate concentrations (hotspot) indicating favorable conditions also for dechlorination of dichlorprop to 4-CPP and further to phenoxypropionic acid. Combined evidence from concentrations, enantiomer ratios and isotope ratios of dichlorprop and 4-CPP confirmed their dechlorination in the hotspot and gave evidence for further degradation of 4-CPP downgradient of the hotspot. A combination of 4-CPP enantiomer and isotope analysis indicated different enantioselectivity and isotope fractionation, i.e. different modes of 4-CPP degradation, at different locations. This combined information was beyond the reach of any of the methods applied alone demonstrating the power of the new combined approach.
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Affiliation(s)
- N Milosevic
- Department of Environmental Engineering, Technical University of Denmark, Miljoevej, Building 113, DK-2800 Kgs. Lyngby, Denmark.
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38
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Bokán K, Syberg K, Jensen K, Rank J. Genotoxic potential of two herbicides and their active ingredients assessed with comet assay on a fish cell line, epithelioma papillosum cyprini (EPC). J Toxicol Environ Health A 2013; 76:1129-1137. [PMID: 24279814 DOI: 10.1080/15287394.2013.843068] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
The aim of this study was to optimize the epithelioma papillosum cyprini (EPC) cell line handling procedure for the comet assay to investigate the genotoxic potential of widely used pesticides. The effects of various media and handling of the EPC cell line were examined. Results indicated that avoiding trypsin to detach cells led to lower level of DNA damage in the negative control. Further, two commonly used herbicides (Dezormon and Optica trio) and their four active ingredients (4-chloro-o-tolyloxyacetic acid, 2,4-dichlorophenoxyacetic acid, 2-(4-chloro-2-methylphenoxy)propionic acid, 2-(2,4-dichlorophenoxy)propionic acid) individually and in a ternary mixture were examined with the comet assay. Data showed that among the active ingredients only 2,4-D and MCPA induced DNA damage, while both herbicides were genotoxic at high concentrations.
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Affiliation(s)
- Katalin Bokán
- a Department of Environmental, Social and Spatial Change (ENSPAC) , Roskilde University , Roskilde , Denmark
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Zhang L, Wang M, Wang C, Hu X, Wang G. Label-free impedimetric immunosensor for sensitive detection of 2,4-dichlorophenoxybutyric acid (2,4-DB) in soybean. Talanta 2012; 101:226-32. [PMID: 23158316 DOI: 10.1016/j.talanta.2012.09.011] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2012] [Revised: 08/31/2012] [Accepted: 09/08/2012] [Indexed: 11/27/2022]
Abstract
Electrochemical impedance immunosensor, with its high sensitivity from electrochemical impedance analysis and ideal specificity from the immunoassay, is increasingly used in the detection of a kind of phenoxy acid herbicides which is 2,4-Dichlorophenoxybutyric acid (2,4-DB). In this experiment, synthetic 2,4-DB antibodies were immobilized on the electrode by the crosslinking of L-Cysteine/glutaraldehyde, and 2,4-DB were measured by the increase of electron-transfer resistance when the immune reaction occurred, with Fe(CN)(6)(3-)/Fe(CN)(6)(4-) as the probe. Under optimal conditions, the change of resistance is in a linear relationship with the logarithm of the concentration in the range of 1.0×10(-7)-1.0×10(-3) g/L (R=0.994) with the detection limit of 1.0×10(-7) g/L (0.1 ppb). This method bears such merits as simplicity in operation, high sensitivity, wide linear range, specificity, reproducibility and good stability. The actual soybean samples were analyzed with the recovery of 82.8%-102.3%.
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Affiliation(s)
- Li Zhang
- College of Chemistry and Chemical Engineering, Jiangsu Key Laboratory of environmental engineering and monitoring, Yangzhou University, 180 Si-Wang-Ting Road, Yangzhou 225002, China
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40
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Ma Y, Jiang J, Xu C, Lu X. Enantioselective inhibition of dichlorprop on catalase. Bull Environ Contam Toxicol 2012; 89:945-949. [PMID: 22961377 DOI: 10.1007/s00128-012-0815-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/2009] [Accepted: 08/30/2012] [Indexed: 06/01/2023]
Abstract
The enantioselectivity interaction of 2,4-dichlorprop (DCPP) and catalase were studied, and it was further evaluated with the presence of humus. Both of rac-DCPP and R-DCPP can inhibit the activity of catalase with the concentrations of 0.05-80 mg L(-1), the inhibitory type of rac-DCPP was uncompetitive, and of R-DCPP was complex. The presence of humic acid has changed the inhibitory ability of DCPP on catalase, the inhibition of rac-DCPP disappeared and the inhibition type of R-DCPP mainly became uncompetitive. These results suggest that inhibition of chiral DCPP on catalase is enantioselective.
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Affiliation(s)
- Yun Ma
- Research Center of Environmental Science, Zhejiang University of Technology, Hangzhou 310032, People's Republic of China.
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41
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Hoppe-Jones C, Dickenson ERV, Drewes JE. The role of microbial adaptation and biodegradable dissolved organic carbon on the attenuation of trace organic chemicals during groundwater recharge. Sci Total Environ 2012; 437:137-144. [PMID: 22940041 DOI: 10.1016/j.scitotenv.2012.08.009] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2012] [Revised: 08/01/2012] [Accepted: 08/02/2012] [Indexed: 06/01/2023]
Abstract
It is widely recognized that efficient biological attenuation of bulk organic matter and trace organic chemicals (TOrC) can occur in managed aquifer recharge (MAR) systems receiving reclaimed water. The heterotrophic microbial activity in these subsurface systems is a function of the availability of biodegradable dissolved organic carbon (BDOC) present in reclaimed water. This study examined the influence of environmental factors, such as BDOC-rich (>1.6 mg/L) and BDOC-starving (<1mg/L) conditions and microbial adaptation, on the attenuation of TOrC, including clofibric acid, dichlorprop, gemfibrozil, ibuprofen, ketoprofen, mecoprop, and naproxen, within soil-columns mimicking groundwater recharge. Under conditions that were characterized by a lack of BDOC and a biocommunity that was not yet adapted to these conditions, attenuation of biodegradable TOrC was less than 15%. After a three-month adaptation period, biotransformation increased to more than 80% for the biodegradable TOrC. This suggests that adaptation likely initiates enzyme expressions that eventually results in TOrC transformations even under seemingly less favorable conditions (i.e., lack of biodegradable carbon). For both non-adapted (stressed) and adapted conditions in the presence of higher concentrations of BDOC and travel times of 7 days, the degree of biotransformation was variable across compounds but generally exceeded 25%. This suggests that BDOC above a minimum level (>1.6 mg/L) can provide favorable microbial conditions resulting in TOrC removal, even for non-adapted systems. However, it is noteworthy that adapted MAR systems that were fed with low BDOC levels performed similarly or better with respect to TOrC biotransformation than systems that received BDOC levels above 1.6 mg/L. These findings are important for field-scale applications. They suggest that MAR facilities that are microbiologically active and are fed with highly treated water with effluent concentrations of less than 1 mg/L (i.e., nanofiltration permeate) can still attenuate biodegradable TOrC.
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Affiliation(s)
- Christiane Hoppe-Jones
- Advanced Water Technology Center (AQWATEC), Department of Civil and Environmental Engineering, Colorado School of Mines, Golden, CO 80401-1887, USA
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42
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Chen H, Chen J, Guo Y, Wen Y, Liu J, Liu W. Evaluation of the role of the glutathione redox cycle in Cu(II) toxicity to green algae by a chiral perturbation approach. Aquat Toxicol 2012; 120-121:19-26. [PMID: 22609738 DOI: 10.1016/j.aquatox.2012.04.011] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/17/2012] [Revised: 04/18/2012] [Accepted: 04/19/2012] [Indexed: 06/01/2023]
Abstract
The effect of heavy metal toxicity on the environment is usually linked to changes in the glutathione redox cycle and oxidative damage as causative events. However, it is unknown whether changes in the glutathione redox cycle are a cause or result of Cu(II) toxicity. Herein, a new chiral perturbation strategy involving a chiral herbicide, dichlorprop (DCPP), as a perturbation factor was used. According to the dose-response fitting curve of DCPP and the combination with Cu(II), 40 μM (R)-DCPP and (S)-DCPP, whose toxicities were low enough to not significantly perturb the Cu(II) toxicity, were selected as the chiral perturbation factor. When Scenedesmus obliquus was incubated with the chiral perturbation factor and 10 μM Cu(II), chiral perturbation was observed in the chlorophyll content and the PAM chlorophyll fluorescence. Then, the role of the glutathione redox cycle in the toxicity of Cu(II) was evaluated with the chiral perturbation approach. The results revealed that the GSH differences in algae cells exposed to (R)-DCPP or (S)-DCPP were well correlated with the differences in the production of reactive oxygen species (ROS) after exposure to the two enantiomers. When (R)-DCPP or (S)-DCPP was added with Cu(II) to the algae culture, treatment with (R)-DCPP-Cu resulted in a decrease in the GSH content in algae cells compared to the control, whereas treatment with (S)-DCPP-Cu resulted in an increase in the GSH. The GSH/GSSG ratio and GR activity also showed similar enantioselectivities. The enantioselectivities would not exist if the changes of in glutathione redox cycle were the cause. Therefore, these data provide indirect evidence that ROS induced cell toxicity of Cu is a causative event, which results in the response of the glutathione redox cycle. These results also provided an implication that before sustainable detoxification strategies for heavy metal pollutants were proposed, it is better that the roles of ROS production and glutathione redox cycle are elucidated. In this case, the chiral perturbation strategy may be a good choice.
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Affiliation(s)
- Hui Chen
- Institute of Environmental Science, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China
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43
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Liu C, Li L, Wang S, You X, Jiang S, Liu F. Dissipation and residue of 2,4-D isooctyl ester in wheat and soil. Environ Monit Assess 2012; 184:4247-4251. [PMID: 21814720 DOI: 10.1007/s10661-011-2259-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/26/2010] [Accepted: 07/15/2011] [Indexed: 05/31/2023]
Abstract
A simple analytical method was developed to determine the 2,4-D isooctyl ester residue in wheat and soil by gas chromatography coupled with electron capture detector. Using the method, the dissipation and residue of 2,4-D isooctyl ester in wheat field was investigated. The average recoveries of 2,4-D isooctyl ester ranged from 80.1% to 110.0% with relative standard deviations of 2.4% to 16.1%. The pesticide showed a rapid dissipation rate either in wheat seedling or soil, with the half-lives of 1.0 to 3.0 days. The terminal residue results in wheat grain were much lower than the codex MRL (2.0 mg/kg). It could be considered safe to food and environment when using this herbicide for controlling weeds in wheat field.
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Affiliation(s)
- Congyun Liu
- College of Science, China Agricultural University, Beijing, 100193, People's Republic of China
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Bernhardt K, Wilkinson S, Weber APM, Linka N. A peroxisomal carrier delivers NAD⁺ and contributes to optimal fatty acid degradation during storage oil mobilization. Plant J 2012; 69:1-13. [PMID: 21895810 DOI: 10.1111/j.1365-313x.2011.04775.x] [Citation(s) in RCA: 75] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
The existence of a transport protein that imports cytosolic NAD(+) into peroxisomes has been controversially discussed for decades. Nevertheless, the biosynthesis of NAD(+) in the cytosol necessitates the import of NAD(+) into peroxisomes for numerous reduction/oxidation (redox) reactions. However, a gene encoding such a transport system has not yet been identified in any eukaryotic organism. Here, we describe the peroxisomal NAD(+) carrier in Arabidopsis. Our candidate gene At2g39970 encodes for a member of the mitochondrial carrier family. We confirmed its peroxisomal localization using fluorescence microscopy. For a long time At2g39970 was assumed to represent the peroxisomal ATP transporter. In this study, we could show that the recombinant protein mediated the transport of NAD(+) . Hence, At2g39970 was named PXN for peroxisomal NAD(+) carrier. The loss of PXN in Arabidopsis causes defects in NAD(+) -dependent β-oxidation during seedling establishment. The breakdown of fatty acid released from storage oil was delayed, which led to the retention of oil bodies in pxn mutant seedlings. Based on our results, we propose that PXN delivers NAD(+) for optimal fatty acid degradation during storage oil mobilization.
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Affiliation(s)
- Kristin Bernhardt
- Institut für Biochemie der Pflanzen, Heinrich-Heine Universität Düsseldorf, 40225 Düsseldorf, Germany
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45
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Peng X, Pang J, Deng A. [Determination of seven phenoxyacid herbicides in environmental water by high performance liquid chromatography coupled with three phase hollow fiber liquid phase microextraction]. Se Pu 2011; 29:1199-1204. [PMID: 22500447] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2023] Open
Abstract
A novel method for the simultaneous determination of seven phenoxyacid herbicides such as dicamba, fluroxypyr, 4-chlorophenoxyacetic acid (4-CPA), 2-methyl-4-chlorophenoxyacetic acid (MCPA), 2, 4-dichlorophenoxyacetic acid (2,4-D), 2,4-dichlorophenoxybutyric acid (2,4-DB) and 4-(2-methyl-4-chlorophenoxy) butyric acid (MCPB) in environmental water by three phase hollow fiber liquid phase microextraction (HF-LPME) coupled with high performance liquid chromatography (HPLC) was developed. In order to optimize the experimental conditions, the orthogonal test has been used. The effects of extraction solvent, pH of the donor phase and acceptor phase, extraction time, stirring speed and salt concentration on the detection were investigated. The optimal experimental conditions were as follows: octanol as organic solvent, pH 3 of donor phase, pH 12 of acceptor phase, extraction time of 30 min, stirring speed of 400 r/min. The results showed that the proposed method provided a wide linear range for 7 phenoxyacid herbicides with correlation coefficients of 0.995 3 - 0.998 8. The detection limits ranged from 0.2 to 1.0 microg/L. The enrichment factors were in the range of 76.7 - 121. The recoveries were in the range of 68% - 104% and the relative standard deviations (RSDs) were less than 8.1% for the environmental water samples. The method has the advantages of sensitivity, simplicity, fastness and the use of very small amounts of organic solvent. The method can meet the requirements of the determination of trace phenoxyacid herbicides in the environmental water samples, and the study provided a useful method for the analysis of trace substances in water samples.
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Affiliation(s)
- Xiaojun Peng
- Xinhui Entry-Exit Inspection and Quarantine Bureau, Jiangmen 529100, China.
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Kim EY, Seo YS, Kim WT. AtDSEL, an Arabidopsis cytosolic DAD1-like acylhydrolase, is involved in negative regulation of storage oil mobilization during seedling establishment. J Plant Physiol 2011; 168:1705-9. [PMID: 21477884 DOI: 10.1016/j.jplph.2011.03.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2011] [Revised: 03/03/2011] [Accepted: 03/03/2011] [Indexed: 05/12/2023]
Abstract
Mobilization of seed storage reserves is essential for seed germination and seedling establishment. Here, we report that AtDSEL, an Arabidopsis thalianaDAD1-like Seedling Establishment-related Lipase, is involved in the mobilization of storage oils for early seedling establishment. AtDSEL is a cytosolic member of the DAD1-like acylhydrolase family encoded by At4g18550. Bacterially expressed AtDSEL preferentially hydrolyzed 1,3-diacylglycerol and 1-monoacylglycerol, suggesting that AtDSEL is an sn-1-specific lipase. AtDSEL-overexpressing transgenic Arabidopsis plants (35S:AtDSEL) were defective in post-germinative seedling growth in medium without an exogenous carbon source. This phenotype was rescued by the addition of sucrose to the growth medium. In contrast, loss-of-function mutant plants (atdsel-1 and atdsel-2) had a mildly fast-growing phenotype regardless of the presence of an exogenous carbon source. Electron microscopy revealed that 5-day-old 35S:AtDSEL cotyledons retained numerous peroxisomes and oil bodies, which were exhausted in wild-type and mutant cotyledons. The impaired seedling establishment of 35S:AtDSEL was not rescued by the addition of an exogenous fatty acid source, and 35S:AtDSEL seedling growth was insensitive to 2,4-dichlorophenoxybutyric acid, indicating that β-oxidation was blocked in AtDSEL-overexpressers. These results suggest that AtDSEL is involved in the negative regulation of seedling establishment by inhibiting the breakdown of storage oils.
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Affiliation(s)
- Eun Yu Kim
- Department of Systems Biology, College of Life Science and Biotechnology, Yonsei University, Seoul 120-749, Republic of Korea
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47
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Degenhardt D, Cessna AJ, Raina R, Farenhorst A, Pennock DJ. Dissipation of six acid herbicides in water and sediment of two Canadian prairie wetlands. Environ Toxicol Chem 2011; 30:1982-1989. [PMID: 21688306 DOI: 10.1002/etc.598] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2010] [Revised: 02/07/2011] [Accepted: 05/13/2011] [Indexed: 05/30/2023]
Abstract
In the present study, an ephemeral (E) and a semipermanent (SP) wetland were divided into halves using a polyvinyl curtain and one-half of each wetland was treated with dicamba (3,6-dichloro-o-anisic acid), bromoxynil (3,5-dibromo-4-hydroxy-benzonitrile), MCPA [(4-chloro-2-methylphenoxy)acetic acid], 2,4-D [(2,4-dichlorophenoxy)acetic acid], mecoprop-P (R)-2-(4-chloro-o-tolyloxy)propionic acid], and dichlorprop [(RS)-2-(2,4-dichlorophenoxy)propionic acid] such that concentrations in the water simulated an overspraying event, thus representing a worst-case scenario for wetland contamination. Water and sediment samples were taken over the 77-d study period to monitor herbicide concentrations. The dissipation of all six herbicides could be described by first-order reaction kinetics. In water, the field half-life (DT50) values ranged from 2.3 d (bromoxynil) to 31 d (dichlorprop). All six herbicides were detected in sediment samples from both wetlands. Overall, the phenoxypropionic acids (mecoprop-P and dichlorprop) were more persistent than the phenoxyacetic acids (2,4-D and MCPA) in both sediment and water. Use of bromide ion as a conservative tracer indicated that infiltration through sediment was an important route of water loss in both wetlands, especially in wetland E. Because strong correlations were found between the mass of each herbicide and bromide ion mass in wetland SP (r(2) = 0.59-0.76) and wetland E (r(2) = 0.80-0.95), it is likely that herbicide dissipation was due, in part, to mass lost by way of infiltration through sediment.
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Affiliation(s)
- Dani Degenhardt
- Agriculture and Agri-Food Canada, Saskatoon, Saskatchewan, Canada.
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Li XX, Kobayashi F, Ikeura H, Hayata Y. Chlorophenoxyacetic acid and chloropyridylphenylurea accelerate translocation of photoassimilates to parthenocarpic and seeded fruits of muskmelon (Cucumis melo). J Plant Physiol 2011; 168:920-926. [PMID: 21168241 DOI: 10.1016/j.jplph.2010.11.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2010] [Revised: 11/24/2010] [Accepted: 11/25/2010] [Indexed: 05/30/2023]
Abstract
We compared the effect of p-chlorophenoxyacetic acid (p-CPA) and 1-(2-chloro-4-pyridyl)-3-phenylurea (CPPU) on parthenocarpic and seeded muskmelon (Cucumis melo) fruits in regards to fruit development and the transport of photoassimilates from leaves exposed to ¹⁴CO₂ to the developing fruits. Ten days after anthesis (DAA), the fresh weight, total ¹⁴C-radioactivity and contents of ¹⁴C-sucrose and ¹⁴C-fructose were higher in the CPPU-induced parthenocarpic fruits than in seeded fruits. However, at 35 DAA, fresh weight and sucrose content in mesocarp, placenta and empty seeds of the parthenocarpic fruits were lower than in seeded fruits. Also, total ¹⁴C-radioactivity and ¹⁴C-sugar content of the parthenocarpic fruits were lower as well as the translocation rate of ¹⁴C-photoassimilates into these fruits. Application of p-CPA to the parthenocarpic fruits at 10 and 25 DAA increased fresh weight and sugar content. Moreover, these treatments elevated the total ¹⁴C-radioactivity, ¹⁴C-sucrose content and the translocation rate of ¹⁴C-photoassimilates. The ¹⁴C-radioactivity along the translocation pathway from leaf to petiole, stem, lateral shoot and peduncle showed a declining pattern but dramatically increased again in the fruits. These results suggest that the fruit's sink strength was regulated by the seed and enhanced by the application of p-CPA.
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Affiliation(s)
- Xin-Xian Li
- Fruit Processing Research Center, AOHATA Corporation, Takehara, Hiroshima 729-2392, Japan
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Wen Y, Chen H, Shen C, Zhao M, Liu W. Enantioselectivity tuning of chiral herbicide dichlorprop by copper: roles of reactive oxygen species. Environ Sci Technol 2011; 45:4778-4784. [PMID: 21545138 DOI: 10.1021/es2003793] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Reactive oxygen species (ROS) are considered to be the key players in cell toxicity. However, cross talk between the enantioselective toxicity of pesticides, heavy metals, and ROS is poorly understood. To decipher the puzzle, the effects of copper (Cu) on the enantioselective ecotoxicity of the chiral pesticide dichlorprop (DCPP) to Scenedesmus obliquus were investigated. The results showed that the presence of DCPP and Cu, both individually and in combination, caused a sudden increase of ROS. This in turn stimulated the response of antioxidant defenses, impaired subcellular structure and physiological function, and finally resulted in cell growth inhibition. In the absence of Cu, ROS production after exposure to the herbicidally active (R)-enantiomer was higher than that of the (S)-enantiomer, suggesting a preference for an (R)-enantiomer-induced production of ROS. When DCPP and Cu were both added to algae simultaneously, (R)-DCPP preferentially induced production of ROS was observed. However, the enantioselective induced production of ROS was reversed when DCPP was mixed with Cu for 24 h prior to addition to the algae solution. It was also found that the generation of ROS, antioxidant response, and growth inhibition rate in Scenedesmus obliquus were all (R)-enantiomer preferentially induced. These findings implied that ROS play a primary role in chemical contaminant toxicity, and interactions between contaminants can tune the enantioselectivity of chiral herbicides, which should be considered in future risk assessment.
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Affiliation(s)
- Yuezhong Wen
- Institute of Environmental Sciences, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China
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Jena P, Mishra B, Leippe M, Hasilik A, Griffiths G, Sonawane A. Membrane-active antimicrobial peptides and human placental lysosomal extracts are highly active against mycobacteria. Peptides 2011; 32:881-7. [PMID: 21396418 DOI: 10.1016/j.peptides.2011.03.002] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/16/2011] [Revised: 03/02/2011] [Accepted: 03/02/2011] [Indexed: 11/25/2022]
Abstract
Mycobacterium tuberculosis (Mtb), the causative agent of tuberculosis, manifests discreet strategies to subvert host immune responses, which enable the pathogen to survive and multiply inside the macrophages. This problem is further worsened by the emergence of multidrug resistant mycobacterial strains, which make most of the anti-tuberculous drugs ineffective. It is thus imperative to search for and design better therapeutic strategies, including employment of new antibiotics. Recently, naturally produced antimicrobial molecules such as enzymes, peptides and their synthetic analogs have emerged as compounds with potentially significant therapeutical applications. Although, many antimicrobial peptides have been identified only very few of them have been tested against mycobacteria. A major limitation in using peptides as therapeutics is their sensitivity to enzymatic degradation or inactivity under certain physiological conditions such as relatively high salt concentration. Here, we show that NK-2, a peptide representing the cationic core region of the lymphocytic effector protein NK-lysin, and Ci-MAM-A24, a synthetic salt-tolerant peptide derived from immune cells of Ciona intestinalis, efficiently kill Mycobacterium smegmatis and Mycobacterium bovis-BCG. In addition, NK-2 and Ci-MAM-A24 showed a synergistic killing effect against M. smegmatis, no cytotoxic effect on mouse macrophages at bactericidal concentrations, and were even found to kill mycobacteria residing inside the macrophages. We also show that human placental lysosomal contents exert potent killing effect against mycobacteria under acidic and reducing growth conditions. Electron microscopic studies demonstrate that the lysosomal extract disintegrate bacterial cell membrane resulting in killing of mycobacteria.
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Affiliation(s)
- Prajna Jena
- School of Biotechnology, KIIT University, Bhubaneswar 751024, Orissa, India
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