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New [1,2]dithiolo[3,4-b]pyridine-5-carboxamides were synthesized through the reaction of dithiomalondianilide (N,N′-diphenyldithiomalondiamide) with 3-aryl-2-cyanoacrylamides or via a three-component reaction involving aromatic aldehydes, cyanoacetamide and dithiomalondianilide in the presence of morpholine. The structure of 6-amino-4-(2,4-dichloro- phenyl)-7-phenyl-3-(phenylimino)-4,7-dihydro-3H-[1,2]dithiolo[3,4-b]pyridine-5-carboxamide was confirmed using X-ray crystallography. To understand the reaction mechanism in detail, density functional theory (DFT) calculations were performed with a Grimme B97-3c composite computational scheme. The results revealed that the rate-limiting step is a cyclization process leading to the closure of the 1,4-dihydropyridine ring, with an activation barrier of 28.8 kcal/mol. Some of the dithiolo[3,4-b]pyridines exhibited moderate herbicide safening effects against 2,4-D. Additionally, ADMET (Absorption, Distribution, Metabolism, Excretion, Toxicity) parameters were calculated and molecular docking studies were performed to identify potential protein targets. [ABSTRACT FROM AUTHOR]

Over the last decades, biostimulants have been the center of discussion as a sustainable cultivation practice to promote plant growth and protect crops from abiotic stress. Agrochemical products are abundantly used for this purpose, which has resulted in raised international concern. Biostimulants, when used in combination with herbicides in some cases, could act as safeners, reducing the harmful and stressful effects of herbicides, and as a result, this combination can be considered a relatively new agricultural technique. However, they can also have adverse or non-significant effects, something that is strongly affected by the operating mechanisms of their components. In practice, there is a need to identify plant species-biostimulant-herbicide working systems from all the stakeholders of agricultural production. While research is still in its early stages, several studies have been conducted to evaluate various biostimulant and herbicide combinations to contribute to this goal. In this review, studies of their combination in sequential or mixed tank applications have been gathered to see how and if each specific combination can have a potential use in agricultural practice. The results indicated that there are various effects on crops, some of which were positive and others negative or non-significant. The fact that there is a countless number of possible plant species-biostimulant-herbicide combinations to be evaluated is a challenging task. Nevertheless, this review could serve as a foundation for the upcoming research. The aim of this review is to summarize the knowledge of some successful working examples of these three factors that could facilitate the incorporation of biostimulant and herbicide application, either sequentially or in a tank mixture, as a part of the agricultural practice for field crops. [ABSTRACT FROM AUTHOR]

The purpose of this work was to prepare new isatin- and monothiomalondiamide-based indole derivatives, as well as to study the properties of the new compounds. The four-component reaction of 5-R-isatins (R = H, CH3), malononitrile, monothiomalonamide (3-amino-3-thioxo- propanamide) and triethylamine in hot EtOH yields a mixture of isomeric triethylammonium 6′-amino-3′-(aminocarbonyl)-5′-cyano-2-oxo-1,2-dihydro-1′H- and 6′-amino-3′-(aminocarbonyl)- 5′-cyano-2-oxo-1,2-dihydro-3′H-spiro[indole-3,4′-pyridine]-2′-thiolates. The reactivity and structure of the products was studied. We found that oxidation of spiro[indole-3,4′-pyridine]-2′-thiolates with DMSO-HCl system produced only acidification products, diastereomeric 6′-amino-5′-cyano-5-methyl-2-oxo-2′-thioxo-1,2,2′,3′-tetrahydro-1′H-spiro-[indole-3,4′-pyridine]- 3′-carboxamides, instead of the expected isothiazolopyridines. The alkylation of the prepared spiro[indole-3,4′-pyridine]-2′-thiolates upon treatment with N-aryl α-chloroacetamides and α-bromoacetophenones proceeds in a regioselective way at the sulfur atom. In the case of α-bromoacetophenones, ring-chain tautomerism was observed for the S-alkylation products. According to NMR data, the compounds consist of a mixture of stereoisomers of 2′-amino-6′-[(2-aryl-2-oxoethyl)thio]-3′-cyano-2-oxo-1′H-spiro[indoline-3,4′-pyridine]-5′-carboxamides and 5′-amino-3′-aryl-6′-cyano-3′-hydroxy-2-oxo-2′,3′-dihydrospiro[indoline-3,7′-thiazolo[3,2-a]pyridine]-8′-carboxamides in various ratios. The structure of the synthesized compounds was confirmed by IR spectroscopy, HRMS, 1H and 13C DEPTQ NMR studies and the results of 2D NMR experiments (1H-13C HSQC, 1H-13C HMBC). Molecular docking studies were performed to investigate suitable binding modes of some new compounds with respect to the transcriptional regulator protein PqsR of Pseudomonas aeruginosa. The docking studies revealed that the compounds have affinity for the bacterial regulator protein PqsR of Pseudomonas aeruginosa with a binding energy in the range of −5.8 to −8.2 kcal/mol. In addition, one of the new compounds, 2′-amino-3′-cyano-5-methyl-2-oxo-6′-{[2-oxo-2-(p-tolylamino)ethyl]thio}-1′H-spiro-[indoline-3,4′-pyridine]-5′-carboxamide, showed in vitro moderate antibacterial effect against Pseudomonas aeruginosa and good antioxidant properties in a test with 1,1-diphenyl-2-picrylhydrazyl radical. Finally, three of the new compounds were recognized as moderately active herbicide safeners with respect to herbicide 2,4-D in the laboratory experiments on sunflower seedlings. [ABSTRACT FROM AUTHOR]

Herbicide safeners protect cereal crops from herbicide injury by inducing genes and proteins involved in detoxification reactions, such as glutathione S-transferases (GSTs) and cytochrome P450s (P450s). Only a few studies have characterized gene or protein expression profiles for investigating plant responses to safener treatment in cereal crops, and most transcriptome analyses in response to safener treatments have been conducted in dicot model species that are not protected by safener from herbicide injury. In this study, three different approaches were utilized in grain sorghum (Sorghum bicolor (L.) Moench) to investigate mechanisms involved in safener-regulated signaling pathways. An initial transcriptome analysis was performed to examine global gene expression in etiolated shoot tissues of hybrid grain sorghum following treatment with the sorghum safener, fluxofenim. Most upregulated transcripts encoded detoxification enzymes, including P450s, GSTs, and UDP-dependent glucosyltransferases (UGTs). Interestingly, several of these upregulated transcripts are similar to genes involved with the biosynthesis and recycling/catabolism of dhurrin, an important chemical defense compound, in these seedling tissues. Secondly, 761 diverse sorghum inbred lines were evaluated in a genome-wide association study (GWAS) to determine key molecular-genetic factors governing safener-mediated signaling mechanisms and/or herbicide detoxification. GWAS revealed a significant single nucleotide polymorphism (SNP) associated with safener-induced response on chromosome 9, located within a phi-class SbGST gene and about 15-kb from a different phi-class SbGST. Lastly, the expression of these two candidate SbGSTs was quantified in etiolated shoot tissues of sorghum inbred BTx623 in response to fluxofenim treatment. SbGSTF1 and SbGSTF2 transcripts increased within 12-hr after fluxofenim treatment but the level of safener-induced expression differed between the two genes. In addition to identifying specific GSTs potentially involved in the safener-mediated detoxification pathway, this research elucidates a new direction for studying both constitutive and inducible mechanisms for chemical defense in cereal crop seedlings.

The reaction between dithiomalondianilide (N,N'-diphenyldithiomalondiamide) and alkyl 3-aryl-2-cyanoacrylates in the presence of morpholine in the air atmosphere leads to the formation of alkyl 6-amino-4-aryl-7-phenyl-3-(phenylimino)-4,7-dihydro-3H-[1,2]dithiolo[3,4-b]- pyridine-5-carboxylates in 37–72% yields. The same compounds were prepared in 23–65% yields by ternary condensation of aromatic aldehydes, ethyl(methyl) cyanoacetate and dithiomalondianilide. The reaction mechanism is discussed. The structure of ethyl 6-amino-4-(4-methoxyphenyl)-7-phenyl-3-(phenylimino)-4,7-dihydro-3H-[1,2]dithiolo[3,4-b]pyridine-5-carboxylate was confirmed by X-ray crystallography. Two of the prepared compounds showed a moderate growth-stimulating effect on sunflower seedlings. Three of the new compounds were recognized as strong herbicide safeners with respect to herbicide 2,4-D in the laboratory and field experiments on sunflower. [ABSTRACT FROM AUTHOR]

Over the last decades, biostimulants have been the center of discussion as a sustainable cultivation practice to promote plant growth and protect crops from abiotic stress. Agrochemical products are abundantly used for this purpose, which has resulted in raised international concern. Biostimulants, when used in combination with herbicides in some cases, could act as safeners, reducing the harmful and stressful effects of herbicides, and as a result, this combination can be considered a relatively new agricultural technique. However, they can also have adverse or non-significant effects, something that is strongly affected by the operating mechanisms of their components. In practice, there is a need to identify plant species-biostimulant-herbicide working systems from all the stakeholders of agricultural production. While research is still in its early stages, several studies have been conducted to evaluate various biostimulant and herbicide combinations to contribute to this goal. In this review, studies of their combination in sequential or mixed tank applications have been gathered to see how and if each specific combination can have a potential use in agricultural practice. The results indicated that there are various effects on crops, some of which were positive and others negative or non-significant. The fact that there is a countless number of possible plant species-biostimulant-herbicide combinations to be evaluated is a challenging task. Nevertheless, this review could serve as a foundation for the upcoming research. The aim of this review is to summarize the knowledge of some successful working examples of these three factors that could facilitate the incorporation of biostimulant and herbicide application, either sequentially or in a tank mixture, as a part of the agricultural practice for field crops.

Background: Numerous pesticides and herbicides used in excess cause oxidative stress in plants. These chemicals protect plants from weeds and pests, but they also have very negative side effects, making them common abiotic stressors. One of the most significant nutritional crops in the world is the wheat plant. Conditions of herbicide stress have a negative impact on the plant's phonological phases and metabolic pathways. Plants primarily make an effort to adjust to the environment and develop oxidative homeostasis, which supports stress tolerance. Methods: When controlling broadleaf weeds that emerge after cereal crop plants have been planted, bromoxynil is frequently used as a selective-contact herbicide. This study looked at the effects of the cyanobacteria Arthrospira platensis and Nostoc muscorum aqueous extracts, tryptophan, and bromoxynil (Bh) alone or in combination on wheat plant growth parameters. Both tryptophan and cyanobacterial extract were used as chemical and natural safeners against Bh application. The antioxidant activity and transcriptome studies using qRT-PCR were assayed after 24, 48, 72, 96 h, and 15 days from Bh application in the vegetation stage of wheat plants (55 days old). Results: In comparison with plants treated with Bh, wheat plants treated with cyanobacteria and tryptophan showed improvements in all growth parameters. Following application of Bh, wheat plants showed reduced glutathione content, as well as reduced antioxidant enzyme activities of superoxide dismutase, catalase, glutathione peroxidase, and glutathione-s-transferase. The combination of different treatments and Bh caused alleviation of the harmful effect induced by Bh on the measured parameters. Additionally, the expression of glutathione synthase and glutathione peroxidase, in addition to those of three genes (Zeta, Tau, and Lambda) of the GST gene family, was significantly upregulated when using Bh alone or in combination with different treatments, particularly after 24 h of treatment. Conclusion: The current study suggests using cyanobacterial extracts, particularly the A. platensis extract, for the development of an antioxidant defense system against herbicide toxicity, which would improve the metabolic response of developed wheat plants. [ABSTRACT FROM AUTHOR]

Increased broccoli production in the eastern United States necessitates the exploration of novel concepts to improve weed management in this region. Currently, there are minimal selective postemergent herbicide options available for broccoli growers in the southeastern United States. Research was conducted to determine if bentazon, an effective nutsedge herbicide, could be used safely for broccoli when tank-mixed with chelated iron in both greenhouse and field settings. Initial greenhouse screens in Charleston, SC, demonstrated that when 224 g.ha-1 active ingredient of chelated iron was tank-mixed with bentazon, a reduction in injury occurred in most of the cultivars that were evaluated. However, based on injury ratings, yield parameters, and broccoli quality observed in the field, it appears that the applications of chelated iron yielded no positive effects. Furthermore, for some of the broccoli cultivars it appeared to exacerbate bentazon injury in the field. [ABSTRACT FROM AUTHOR]

Increased broccoli production in the eastern United States necessitates the exploration of novel concepts to improve weed management in this region. Currently, there are minimal selective postemergent herbicide options available for broccoli growers in the southeastern United States. Research was conducted to determine if bentazon, an effective nutsedge herbicide, could be used safely for broccoli when tank-mixed with chelated iron in both greenhouse and field settings. Initial greenhouse screens in Charleston, SC, demonstrated that when 224 g⋅ha−1 active ingredient of chelated iron was tank-mixed with bentazon, a reduction in injury occurred in most of the cultivars that were evaluated. However, based on injury ratings, yield parameters, and broccoli quality observed in the field, it appears that the applications of chelated iron yielded no positive effects. Furthermore, for some of the broccoli cultivars it appeared to exacerbate bentazon injury in the field.

Benoxacor (BN) is a highly effective antidote of dichloroacetamide herbicides generally used to protect crops from herbicidal damage. As a commonly used agrochemical, this herbicide antidote is continuously discharged in watercourses thus causing toxicity to aquatic organisms, and ultimately leading to contamination of the food chain. To date, its potential toxicity to the cardiac development of aquatic organisms has not been evaluated. In the present study, we have selected the zebrafish as a model to study the impact of BN on embryonic developmental and cardiac toxicity. The zebrafish embryos were exposed in 0.5, 1.0 and 2.0 mg/L BN from 5.5 to 72 h post-fertilization (hpf). The results indicated that the exposure to BN led to increased mortality and diminished heart and hatching rates in the embryos. BN exposure also brought pericardial edema (PE) and linear stretching of heart. Besides, exposure to BN induced an excessive accumulation of reactive oxygen species (ROS) in the zebrafish embryos and abnormal activities of the antioxidant enzymes, including catalase (CAT) and malondialdehyde (MDA). Moreover, exposure to BN caused serious cardiac toxicity of the embryos, accompanied by abnormality of heart development- and apoptosis-related genes. Surprisingly, astaxanthin (ASTA), as a common antioxidant, was found to be able to partially rescue the cardiac toxicity caused by BN, which indicated that ROS are probably the major reason for the resulting cardiotoxicity in zebrafish embryos. Our results suggest the need for a comprehensive safety evaluation of the regular consumption of benoxacor, which provides scientific basis for the development of health standards and assessment of potential risk in aquatic organisms or even human.

The reaction between dithiomalondianilide (N,N’-diphenyldithiomalondiamide) and alkyl 3-aryl-2-cyanoacrylates in the presence of morpholine in the air atmosphere leads to the formation of alkyl 6-amino-4-aryl-7-phenyl-3-(phenylimino)-4,7-dihydro-3H-[1,2]dithiolo[3,4-b]- pyridine-5-carboxylates in 37–72% yields. The same compounds were prepared in 23–65% yields by ternary condensation of aromatic aldehydes, ethyl(methyl) cyanoacetate and dithiomalondianilide. The reaction mechanism is discussed. The structure of ethyl 6-amino-4-(4-methoxyphenyl)-7-phenyl-3-(phenylimino)-4,7-dihydro-3H-[1,2]dithiolo[3,4-b]pyridine-5-carboxylate was confirmed by X-ray crystallography. Two of the prepared compounds showed a moderate growth-stimulating effect on sunflower seedlings. Three of the new compounds were recognized as strong herbicide safeners with respect to herbicide 2,4-D in the laboratory and field experiments on sunflower.

Background: Numerous pesticides and herbicides used in excess cause oxidative stress in plants. These chemicals protect plants from weeds and pests, but they also have very negative side effects, making them common abiotic stressors. One of the most significant nutritional crops in the world is the wheat plant. Conditions of herbicide stress have a negative impact on the plant’s phonological phases and metabolic pathways. Plants primarily make an effort to adjust to the environment and develop oxidative homeostasis, which supports stress tolerance. Methods: When controlling broadleaf weeds that emerge after cereal crop plants have been planted, bromoxynil is frequently used as a selective-contact herbicide. This study looked at the effects of the cyanobacteria Arthrospira platensis and Nostoc muscorum aqueous extracts, tryptophan, and bromoxynil (Bh) alone or in combination on wheat plant growth parameters. Both tryptophan and cyanobacterial extract were used as chemical and natural safeners against Bh application. The antioxidant activity and transcriptome studies using qRT-PCR were assayed after 24, 48, 72, 96 h, and 15 days from Bh application in the vegetation stage of wheat plants (55 days old). Results: In comparison with plants treated with Bh, wheat plants treated with cyanobacteria and tryptophan showed improvements in all growth parameters. Following application of Bh, wheat plants showed reduced glutathione content, as well as reduced antioxidant enzyme activities of superoxide dismutase, catalase, glutathione peroxidase, and glutathione-s-transferase. The combination of different treatments and Bh caused alleviation of the harmful effect induced by Bh on the measured parameters. Additionally, the expression of glutathione synthase and glutathione peroxidase, in addition to those of three genes (Zeta, Tau, and Lambda) of the GST gene family, was significantly upregulated when using Bh alone or in combination with different treatments, particularly after 24 h of treatment. Conclusion: The current study suggests using cyanobacterial extracts, particularly the A. platensis extract, for the development of an antioxidant defense system against herbicide toxicity, which would improve the metabolic response of developed wheat plants.

Herbicide safeners protect cereal crops from herbicide injury by inducing genes and proteins involved in detoxification reactions, such as glutathione S-transferases (GSTs) and cytochrome P450s (P450s). Only a few studies have characterized gene or protein expression profiles for investigating plant responses to safener treatment in cereal crops, and most transcriptome analyses in response to safener treatments have been conducted in dicot model species that are not protected by safener from herbicide injury. In this study, three different approaches were utilized in grain sorghum (Sorghum bicolor (L.) Moench) to investigate mechanisms involved in safener-regulated signaling pathways. An initial transcriptome analysis was performed to examine global gene expression in etiolated shoot tissues of hybrid grain sorghum following treatment with the sorghum safener, fluxofenim. Most upregulated transcripts encoded detoxification enzymes, including P450s, GSTs, and UDP-dependent glucosyltransferases (UGTs). Interestingly, several of these upregulated transcripts are similar to genes involved with the biosynthesis and recycling/catabolism of dhurrin, an important chemical defense compound, in these seedling tissues. Secondly, 761 diverse sorghum inbred lines were evaluated in a genome-wide association study (GWAS) to determine key molecular-genetic factors governing safener-mediated signaling mechanisms and/or herbicide detoxification. GWAS revealed a significant single nucleotide polymorphism (SNP) associated with safener-induced response on chromosome 9, located within a phi-class SbGST gene and about 15-kb from a different phi-class SbGST. Lastly, the expression of these two candidate SbGSTs was quantified in etiolated shoot tissues of sorghum inbred BTx623 in response to fluxofenim treatment. SbGSTF1 and SbGSTF2 transcripts increased within 12-hr after fluxofenim treatment but the level of safener-induced expression differed between the two genes. In addition to identifying specific GSTs potentially involved in the safener-mediated detoxification pathway, this research elucidates a new direction for studying both constitutive and inducible mechanisms for chemical defense in cereal crop seedlings.

Core Ideas: Postemergence herbicide applications can cause injury to soybean crops.The use of insecticide seed treatments has been shown to reduce injury from some herbicides following emergence in some crops.No previous research has been conducted to examine any similar instance in soybean.Results from this research indicate insecticide seed treatments are not likely to reduce injury from the postemergence herbicides evaluated in soybean. Weed control in soybean production plays a vital role in producing a high‐yielding crop. An important component of effective weed control programs for many soybean producers is the use of postemergence (POST) herbicide applications; however, some crop injury can accompany these applications. While uncommon, this injury can result in yield loss depending on the severity and timing of application. Previous research has shown that, in rice, some neonicotinoid insecticide seed treatments can act as herbicide safeners in addition to protecting against early‐season insect pests. Neonicotinoid seed treatments are extensively used in soybean production, but their utility as herbicide safeners has not been examined. As such, field trials were conducted in Marianna, AR in 2015 and 2016, in addition to near Colt, AR in 2016, to determine whether a safening effect could be observed using thiamethoxam and clothianidin in soybean following applications of POST herbicides that commonly cause crop injury. Chlorimuron, fomesafen, and 2,4‐DB were applied 21 d after planting. In Marianna in 2016, injury from chlorimuron and fomesafen was reduced 8 and 7% points, respectively, in thiamethoxam‐treated seed. At the same location and evaluation timing, clothianidin‐treated seed reduced injury from 2,4‐DB by 8% points 1 week after application (WAA). Additionally, a seed treatment main effect was observed at Marianna in 2016 both 2 WAA and 4 WAA, where a thiamethoxam seed treatment reduced injury 5 and 6% points, respectively, averaged across all herbicides. Aside from Marianna in 2016, visible injury was not reduced at any location or evaluation timing. Additionally, yield was not impacted by seed treatment at any location. Based on the results from these experiments, the insecticides clothianidin and thiamethoxam, applied as seed treatments, are unlikely to successfully safen the evaluated POST‐applied herbicides that are often injurious to soybean. [ABSTRACT FROM AUTHOR]

Graphical abstract Abstract Fragment splicing is a primary strategy in the design and optimization of leading compound toward new skeleton with target bioactivity. Herein a series of novel substituted phenyl oxazole derivatives were designed via fragment analysis and coupling strategy that led to highly potent and bio-selective herbicide safener. The biological tests showed that most of the compounds could enhance the maize growth index, glutathione content and anti-reverse enzyme glutathione S-transferase activity in vivo. The molecular docking model exhibited that the novel compound could compete with chlorsulfuron binding to the herbicide target enzyme, which consequently attained the herbicide detoxification. Especially compound I - f displayed the best activities than commercial safener isoxadifen-ethyl and other compounds. The present work demonstrates that the synthesized compounds could be developed as potential candidates for the discovery of novel herbicide safeners in the future. [ABSTRACT FROM AUTHOR]

Abstract Toxicological testing of plant protection products (PPPs) is a legal requirement in the EU. The whole PPP formulation is tested for acute endpoints in vivo during approval procedure of PPPs. However, alternative methods such as the CLP calculation method (CM) are employed increasingly. In the first part of this study we analysed PPPs for the correlation of GHS classifications resulting mainly from in vivo LD 50 -values with classifications obtained from calculated LD 50 -values using the CM. Accordingly, the CM predicted 80% of the PPPs correctly. However 31% of classified products were not identified revealing a considerable inaccuracy of this method. Based on these results ten PPPs and corresponding ASs were further tested in a cytotoxicity assay employing 3T3 and hFF cells (one PPP and corresponding AS were tested in HepaRG cells). The study outcome revealed that the cytotoxicity data did not reliably reflect differences in toxicity between ASs and PPPs. Especially organic solvent based formulations demonstrated a higher cytotoxicity than water based formulations independently to their toxicity in vivo. Overall, the cytotoxicity test did not provide a more robust method than the CM. However, the database consisting of ten PPPs was small and therefore no robust conclusions can be drawn. Highlights • Reliable alternative methods for the toxicity assessment of formulated PPPs are needed. • An analysis of a broad range of authorized PPPs revealed a significant inaccuracy of the CLP calculation method. • The described cytotoxicity test does not provide a robust method to detect differences in toxicity between ASs and PPPs. • Organic solvent based formulations demonstrate a higher cytotoxicity than water based formulations. • The applicability of HepaRG cells for in vitro testing of PPPs should be further examined. [ABSTRACT FROM AUTHOR]

Salicylic acid (SA) is an endogenous plant hormone that has a wide range of pharmacological effects. Studies have indicated that SA has herbicide safening activity. In this study, the herbicide safening activity of SA and 20 substituted molecules were tested on agar-cultured rice. Biological assay results indicated that SA and substituted SA had a low inhibitory effect on the growth of rice seedlings (Oryza sativa), and partially alleviated the effects of metolachlor toxicity. Moreover, at 0.25 mg L−1, the safening effect of compounds l and u lessened the effects of metolachlor phytotoxicity on plant height and fresh weight when compared to the effects of the control, fenclorim. The effects of metolachlor toxicity were reduced on root length due to the safening effects of compounds l, n, and u; these effects were greater than those of fenclorim. These compounds could facilitate the development of novel herbicide safeners.

Abstract Approximately 242 million kg of herbicides are applied in the United States (US) annually. While herbicides prevent the growth of weeds, they can damage crops resulting in so called “herbicide injury.” To increase herbicidal tolerance of crops, herbicide safeners are commonly added to formulations. Herbicidal safeners are labeled as inert ingredients in herbicide formulations and typically minimal fate and transport information is available. The objective of this study is to experimentally derive the aqueous solubility, octanol-water partition coefficient, and photo-degradation and permanganate oxidation of two dichloroacetamide safeners, benoxacor and furilazole. These results can be used to understand the environmental chemodynamics of these compounds and their degradation via common drinking water treatment systems containing permanganate. The aqueous solubility of benoxacor and furilazole was 22 and 235 mg L−1 respectively while the estimated solubility from EPI Suite was 102.7 and 255 mg L−1 respectively. The log octanol-water partition coefficient of benoxacor and furilazole was 2.23 and 1.96 respectively. The selected safeners were not photodegradable to any great extent. Both benoxacor and furilazole oxidation were found to be second order with respect to initial KMnO 4 concentrations. The results of this study can be used to predict distribution of safeners after application in agricultural fields and aid in the design of treatment systems. Graphical abstract Image 1 Highlights • Herbicide safener solubility and log K ow differs from computational estimates. • Safener K ow estimates suggest low bioaccumulation potential. • Safeners, benoxacor and furilazole, were not photodegradable. • Permanganate oxidation of safeners followed second order kinetics. • Safeners will likely persist in aquatic environments. [ABSTRACT FROM AUTHOR]

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The compound N-(4,6-dichloropyrimidine-2-yl)benzamide (C11H7Cl2N3O) was synthesized and the corresponding structure was confirmed by ¹H NMR, 13C NMR, HRMS, IR, and single-crystal X-ray diffraction. The compound crystallized in a monoclinic system with space group P 21/c, where a = 14.9156(6), b = 16.6291(8), c = 14.4740(6) Å, b = 95.160(2)°, V = 3575.5(3) ų, Z = 12, Dc = 1.494 g·cm-3, F(000) = 1632, m(MoKa) = 3.182 mm-1, final R = 0.0870, and wR = 0.2331 with I > 2σ(I). The crystal structure was found to be stabilized by intermolecular hydrogen bonding interactions N-H···O and C-H···Cl. Furthermore, the results from biological assays indicated that the compound showed a similar protective effect on metolachlor injury in rice seedlings compared to fenclorim at a concentration of 4.0 mg·L-1. Moreover, the compound exhibited an improved antifungal activity compared to pyrimethanil against S. sclerotiorum and F. oxysporum. Potentially, these results lay the foundation for the development of novel herbicide safeners and fungicides. [ABSTRACT FROM AUTHOR]

A series of novel methyl (R)-N-benzoyl/dichloroacetyl-thiazolidine-4-carboxylates were designed by active substructure combination. The title compounds were synthesized using a one-pot route from L-cysteine methyl ester hydrochloride, acyl chloride, and ketones. All compounds were characterized by IR, ¹H NMR, 13C NMR, and HRMS. The structure of 4q was determined by X-ray crystallography. The biological tests showed that the title compounds protected maize from chlorimuron-ethyl injury to some extent. The ALS activity assay showed that the title compounds increased the ALS activity of maize inhibited by chlorimuron-ethyl. Molecular docking modeling demonstrated that Compound 4e competed against chlorimuron-ethyl to combine with the herbicide target enzyme active site, causing the herbicide to be ineffective. [ABSTRACT FROM AUTHOR]

This investigation was undertaken to determine whether active ingredients (AIs) of currently recommended plant protection products (PPPs) could be transferred to beehives from apple and pear trees. A field trial was carried out with apple trees of Ligol and Idared variety, and pear trees of Conference variety. For pest and diseases control of fungal origin, recommended PPPs were applied. Samples of flowers from the above-mentioned varieties of fruit trees, of bees, brood and honey from beehives located in their direct neighborhood were collected regularly and analyzed for the presence of lambdacyhalothrin (an insecticide) and cyprodinil, captan, fluopyram, kresoxim-methyl, penthiopyrad and trifloxystrobin (fungicides). In samples of flowers of Ligol variety, fluopyram residues (on average 0.621 μg single flower-1) were at the highest levels, whereas in samples of pear flowers of Conference variety, and in flowers of Idared variety, captan residues (on average, respectively, 0.705 and 165.7 μg single flower-1). In samples of bees and honey, residues of five AIs were detected, and in brood six AIs, whereby in each case captan residues prevailed, respectively, up to 585.2, 51.52 and 126.5 μg kg-1 bees and honey. In the honey, significantly larger residues of captan were found out than maximum residue level (MRL) for this AI - 103.04% MRL. In the case of any AI, the daily intake did not exceed 0.002% acceptable daily intake (ADI). [ABSTRACT FROM AUTHOR]

Summary: Plants contain large numbers of family 1 UDP‐glucose‐dependent glycosyltransferases (UGTs), including members that conjugate xenobiotics. Arabidopsis contains 107 UGT genes with 99 family members successfully expressed as glutathione transferase (GST)‐fusion proteins in E. coli. A high‐throughput catalytic screen was developed based on quantification of the fusion by measuring GST activity. UGT activity using UDP‐glucose as donor was then determined using 11 synthetic acceptors bearing hydroxyl, amino and thiol groups that had been shown to undergo conjugation in plant extracts. In total, 44 UGTs, largely members of the D and E groups, were active towards xenobiotics, glucosylating phenol and thiol acceptors. In contrast, N‐glucosyltransferase (NGT) activity was almost exclusively restricted to a single enzyme, UGT72B1. Using DNA microarrays, the induction of UGT transcripts following treatment with the herbicide safener fenclorim was compared in Arabidopsis and rice. D and L group members were the most safener‐inducible UGTs in both species. The respective Arabidopsis enzymes showed low conjugating activity towards xenobiotics. Using Genevestigator, a small group of safened D and L UGTs were consistently induced in response to biotic and abiotic stress suggestive of protective activities beyond xenobiotic detoxification in both species. The induction of other detoxifying gene families following treatment with fenclorim, namely cytochromes P450 and glutathione transferases, further confirmed the selective enhancement of related subfamily members in the two species giving new insight into the safening response in cereals, where herbicide tolerance is enhanced compared with dicots, which are unresponsive to these treatments. [ABSTRACT FROM AUTHOR]

In the last decades, many anthropogenic activities have resulted in heavy metal contamination of freshwaters and surrounding environments. This poses serious threats to human health. Phytoremediation is a cost-effective technology which is useful for remediating polluted soils and water. Recently, the use of aquatic free-floating plants has been proposed to remediate polluted water. In this context, a study on the capacity of two aquatic plants, Lemna minor (duckweed) and Salvinia auriculata (salvinia), to remediate Cu + 2 (Cu) polluted water was carried out. Initially, the species were exposed to different copper concentrations (1, 5, 10, 20 and 50 μmol L − 1 ) in order to assess Cu + 2 toxicity to the plants. In addition, plants were treated with two safeners (benoxacor and dichlormid), with the aim of pointing out any safening effect of these compounds on the aquatic species. Toxicity tests showed that safened plants had a greater Cu resistance, especially at the higher Cu doses. Finally, unsafened and safened plants were tested in the decontamination of water polluted by copper (1.2 mg L − 1 ). In general, duckweed removed higher amounts of Cu from polluted water than salvinia, and, surprisingly, for both the species the safeners significantly increased the plants' capacity to remove the metal from the polluted waters. Lastly, an HPLC-based method was developed and standardized to monitor the residual amounts of the two safeners in the water. While dichlormid was completely absorbed by duckweed within few days after the treatments, some residual amounts of both safeners were found in salvinia vegetated water after two weeks. In conclusion, the results of this research show that the use of aquatic species in combination with safeners is an attractive and reliable tool to make plants more effective in phytoremediation of water polluted with metals (or other toxic compounds). [ABSTRACT FROM AUTHOR]

The environmental effects of safeners, agrochemicals that protect crops from herbicide toxicity, are largely unknown, perhaps because they are classified as inert ingredients. We assessed the toxicity to larvae of Chironomus riparius of 1) the dichloroacetamide safener benoxacor; 2) its degradation product, monochloro-benoxacor; 3) the herbicide with which benoxacor is paired, S-metolachlor; and 4) a mixture of S-metolachlor + benoxacor. Under iron-reducing conditions, benoxacor can undergo reductive dechlorination, producing monochloro-benoxacor. To simulate iron-reducing conditions, we prepared benthic microcosms containing an iron-rich silt-clay sediment amended with cellulose. Larval C. riparius were exposed to single chemicals via spiked sediment at nominal concentrations ranging from 0.01 to 100 mg/kg. Concentrations of a 1:1 mixture of safener and herbicide ranged from 0.02 to 200 mg/kg. Kinetic modeling of microcosm aqueous-phase concentrations indicated that benoxacor transformed with a half-life of 12 d. Cox proportional hazard models of time to emergence during 28-d experiments showed that females had a lowest-observed-effect concentration (LOEC) for benoxacor at 1 mg/kg, whereas their LOEC for monochloro-benoxacor was 0.1 mg/kg. For males, the LOEC for all treatments was 100 mg/kg (200 mg/kg for the mixture). Synergistic effects of the mixture were observed only in females, with a LOEC of 0.2 mg/kg. These results suggest that benoxacor presents a low toxicity risk to C. riparius in environmental systems; however, the possibility of synergistic effects between benoxacor and S-metolachlor merits further investigation. Environ Toxicol Chem 2017;36:2660-2670. © 2017 SETAC [ABSTRACT FROM AUTHOR]

In a genome context, sugarcane is a classic orphan crop, in that no genome and only very few genes have been assembled. We have devised a novel exome assembly methodology that has allowed us to assemble and characterize 49 genes that serve as herbicide targets, safener interacting proteins, and members of herbicide detoxification pathways within the sugarcane genome. We have structurally modelled the products of each of these genes, as well as determining allelic, genomic, and RNA-Seq based polymorphisms for each gene. This study provides the largest collection of sugarcane structures modelled to date. We demonstrate that sugarcane genes are highly polymorphic, revealing that each genotype is evolving both uniquely and independently. In addition, we present an exome assembly system for orphan crops that can be executed on commodity infrastructure, making exome assembly practical for any group. In terms of knowledge about herbicide modes of action and detoxification, we have advanced sugarcane from a crop where no information about any herbicide-associated gene was available to the situation where sugarcane is now a species with the single largest collection of known and annotated herbicide-associated genes. [ABSTRACT FROM AUTHOR]

Predators can decrease herbivore damage to plants, and this is often assumed to be beneficial to plant growth/reproduction without actual quantification. Moreover, previous studies have been biased towards strict carnivores and neglected the role of omnivorous predators in prey-suppression. Here, we examined the costs (reduction in growth) and benefits (increase in growth) of enemy-mediated plant protection via the omnivorous (prey and plant-feeding) Orthotylus marginalis, relative to herbivory by a detrimental insect pest of Salix spp. plantations, the beetle Phratora vulgatissima. In a first experiment, we compared the cost of adult beetle versus omnivore nymph plant-feeding, and assessed the (non-) additive effects of the two types of damage. In a second experiment, we quantified the reduction in plant damage resulting from beetle-egg feeding by omnivorous nymphs and subsequent benefits to plants. We found that plant-feeding by omnivores negatively affected plant growth and this effect was similar to the cost imposed by beetle herbivory. Furthermore, simultaneous damage effects were additive and more detrimental than individual effects. While egg-predation by omnivore nymphs completely prevented beetle damage to plants, there was no difference in plant growth relative to only herbivore-damaged plants and growth was still reduced compared to control plants. Thus, despite herbivore suppression, there was no benefit to plant growth of omnivore-mediated plant protection and the negative effects of omnivore plant-feeding remained. These results are a first for an omnivorous enemy, and provide novel and timely insights on the underlying assumptions of tri-trophic associations and their use for biocontrol of insect pests. [ABSTRACT FROM AUTHOR]

The compound N-(4,6-dichloropyrimidine-2-yl)benzamide (C11H7Cl2N3O) was synthesized and the corresponding structure was confirmed by 1H NMR, 13C NMR, HRMS, IR, and single-crystal X-ray diffraction. The compound crystallized in a monoclinic system with space group P 21/c, where a = 14.9156(6), b = 16.6291(8), c = 14.4740(6) Å, β = 95.160(2)°, V = 3575.5(3) Å3, Z = 12, Dc = 1.494 g∙cm−3, F(000) = 1632, μ(MoKa) = 3.182 mm−1, final R = 0.0870, and wR = 0.2331 with I > 2σ(I). The crystal structure was found to be stabilized by intermolecular hydrogen bonding interactions N–H···O and C–H···Cl. Furthermore, the results from biological assays indicated that the compound showed a similar protective effect on metolachlor injury in rice seedlings compared to fenclorim at a concentration of 4.0 mg∙L−1. Moreover, the compound exhibited an improved antifungal activity compared to pyrimethanil against S. sclerotiorum and F. oxysporum. Potentially, these results lay the foundation for the development of novel herbicide safeners and fungicides.

BACKGROUND Safeners are agrochemicals used in agriculture to protect crops from herbicide injuries. They act by stimulating herbicide metabolism. As graminaceous plants, to cope with iron (Fe) deficiency, activate sulfur (S) metabolism and release huge amounts of Fe-chelating compounds, or phytosiderophores ( PSs), we investigated, in barley plants ( Hordeum vulgare, L.) grown in Fe deficiency, the effects of three safeners on two enzymes of S assimilation, cysteine (Cys) and glutathione ( GSH), and PS release. Finally, we monitored the root Fe content in plants treated with the most effective safener. RESULTS Generally, all the safeners activated S metabolism and increased Cys and GSH contents. In addition, the safened plants excreted higher levels of PSs. Given that mefenpyr-diethyl (Mef) was the most effective in causing these effects, we assessed the Fe concentration in Mef-treated barley and found higher Fe levels than those in untreated plants. CONCLUSION The three safeners, in different ways but specifically, activated S reductive metabolism and regulated Cys and GSH contents, PS release rate and Fe content (Mef-treated barley). The results of this research provide new indications of the biochemical and physiological mechanisms involved in the safening action. © 2016 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

In this study, the effects of Ligusticum chuanxiong extract as herbicide safeners were determined on glutathione-S-transferase (GST) activity of rice crop. Two main extract compounds, Z-ligustilide and senkyunolide A, were identified by high performance liquid chromatography and liquid chromatography-mass spectrometry. In both bioassays conducted in agar and soil, the whole L. chuanxiong extract, as well as two active components individually were effective in safening the growth of rice seedlings against S-metolachlor toxicity. Z-Ligustilide was a better safener than senkyunolide A, and both compounds were more protective of shoots than roots. After herbicide-inhibited rice seedlings were treated with Z-ligustilide, GST activity significantly increased, suggesting the safening effect of this L. chuanxiong extract component involves GST. [ABSTRACT FROM AUTHOR]

Safeners are an important tool used to ensure the safe using of herbicide. The objective of this paper was to investigate the protective effect of four 3-dichloroacetyl oxazolidine safeners (3-dichloroacetyl-2,2-dimethyl-1,3-oxazolidine [R-28725], racemate of 3-dichloroacetyl-2,2-dimethyl-4- ethyl-1,3-oxazolidine, and its two chiral stereoisomers) in reducing the injury caused by imazethapyr. Physiological and biochemical tests were conducted under laboratory condition, by using seed treatment with safeners and soil treatment with imazethapyr, respectively. The interaction of two safeners (R-28725 and R-stereoisomer) and imazethapyr reduced the injury of maize significantly, and also increased glutathione content, activity of glutathione S-transferases, and activity of acetolactate synthase in maize. When induced by R-stereoisomer, the GSH content in root and in shoot increased 100.7% and 73.6%, respectively. When induced by R-28725, the GST activity in vivo increased threefold and the GST activity in vitro more than doubled. The kinetic parameter Vmax of GST in the maize treated with R-28725 and R-stereoisomer increased by 102.2% and 81.9%, respectively, compared with the control. The results also showed that R-28725 and R-stereoisomer induced glutathione S-transferases affinity for the substrate of conjugation reaction significantly. [ABSTRACT FROM AUTHOR]

Agriculture is facing an enormous challenge: it must ensure that enough high-quality food is available to meet the needs of a continually growing population. Current and future agronomic production of food, feed, fuel and fibre requires innovative solutions for existing and future challenges, such as climate change, resistance to pests, increased regulatory demands, renewable raw materials or requirements resulting from food chain partnerships. Modern agricultural chemistry has to support farmers to manage these tasks. Today, the so-called 'side effects' of agrochemicals regarding yield and quality are gaining more importance. Agrochemical companies with a strong research and development focus will have the opportunity to shape the future of agriculture by delivering innovative integrated solutions. This review gives a comprehensive overview of the innovative products launched over the past 10 years and describes the progress of modern agricultural chemistry and its future prospects. © 2015 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Acanthotomicus sp. has become a lethal pest of American sweetgum (Liquidambar slyracijlua), causing the death of a large number of trees in Jiangsu and Shanghai. The damage characters, morphological characteristics and living habits of Acanthotomicus sp. are briefly described, and various prevention and control methods are proposed. [ABSTRACT FROM AUTHOR]

Herbicide safener, a diverse group of chemicals, is an important tool used to protect plants from herbicidal injury. With the aim of decreasing drift injury of haloxyfop-P-methyl to sensitive plants, the protective effect of four safeners (R-28725, 3-dichloroacetyl oxazolidine and its two optical isomers) was evaluated. Physiological and biochemical tests were conducted under laboratory conditions in Northeast Agricultural University, China, by using seed treatment with safener and soil treatment with haloxyfop-P-methyl, respectively. The maize seeds treated with these safeners were safe from haloxyfop-P-methyl treatment. A positive correlation between growth level and endogenous glutathione (GSH) content, glutathione S-transferases (GST) activity was observed in this research. Enhancement of GSH content, GST activity and affinity of GST to 1-chloro-2,4-dinitrobenzene (CDNB) in maize treated by R-28725 was maximum. However, the detoxification of herbicide was not accompanied by the increase of acetyl-CoA-carboxylase (ACC) activity in maize. [ABSTRACT FROM AUTHOR]

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The excessive use of plant protection products (PPPs) has given rise to issues of public and environmental health because of their toxicity. Reducing the use of toxic PPPs and replacing them with products that are less toxic for human health and the environment have become socially, environmentally and economically indispensable. In this article, we assess the plant protection practices of a small group of winegrowers practicing 'integrated agriculture' in the south of France, in order to measure the benefit of using toxicity risk indicators as a decision-support tool for different players in land management. An analysis of plant protection practices using indicators of the risk to operator health and the environment (IRSA, IRTE), together with a frequency-of-treatment indicator (TFI), enabled us to (i) show the variability of these indicators depending on the production system and farmers' pesticide use strategies and (ii) calculate correlations between these indicators. This analysis of plant protection practices at different scales (farm, field), carried out in collaboration with the growers, enabled us to perform an initial validation of decision-support tools for determining risk management strategies regarding the use of pesticides. [ABSTRACT FROM AUTHOR]

Study of safeners has been seldom reported in literature. In this work, a series of novel acylsulfamoylbenzamide analogues was designed and synthesized with newly developed safener cyprosulfamide ( CSA ) as the leading compound. The activity assay against the herbicide thiencarbazone-methyl ( TCM ) on maize revealed that fifteen compounds showed better protective effect than CSA on the fresh weight of aerial parts, twelve compounds exhibited better activity on the dry weight of aerial parts. Remarkably, two compounds ( 6Ih , 7II ) had protective effect on the four aspects of TCM treated maize. Further antifungal assay showed their excellent activity against Physollospora piricola . The structure–activity relationships of CSA analogues as safeners and fungicides were discussed and it might be valuable for further molecular modification of new CSA analogues. [ABSTRACT FROM AUTHOR]

The protective effect of herbicide safener R-28725 and chiral 3-dichloroacetyl oxazolidine safeners in reducing the phytotoxicity of chlorsulfuron to maize were studied by physiological and biochemical tests. The results showed that R-28725 and compound A [(R)-3-dichloroacetyl-2,2-dimethyl-4-ethyl-1,3-oxazolidine] could improve the GSH content, GST activity (in vivo and in vitro), ALS activity and GST affinity for the CDNB substrate in maize and the maize could be restored from the injury by chlorsulfuron. © 2015 Friends Science Publishers [ABSTRACT FROM AUTHOR]

India has recently enacted Distinctiveness, Uniformity and Stability (DUS) characterization for rice. This paper focuses on DUS characterization using morphological descriptors for 21 rice varieties planted in a randomized block design during two kharif seasons (2007 and 2008). Data were recorded for 60 DUS descriptors (46 qualitative and 14 quantitative) folloiving guidelines from the International Union for the Protection of New Varieties of Plants (UPOV) and the Protection of Plant Varieties and Farmer's Rights Authority (PPV & FRA). Data on quantitative traits were subjected to Combined Over Years Distinctness (COYD) and Combined Over Years Uniformity (COYU) analyses. The descriptors offering the most discrimination were time to 50% heading, decorticated grain shape, and the colour of lemma and palea. The cultivar Sathi, an improved landrace entry, was observed to be the most distinct, with the rarest morphological features. Eight of the 21 qualitative and 8 of the 14 quantitative traits exhibited uniformity as determined by UPOV-recommended levels. Tivelve of the quantitative traits were relatively stable as judged by seasonal variation in Phenotypic Coefficient of Variation (PCV) and Genotypic Coefficient of Variation (GCV) values. Finally, the varieties were clustered following the eight grouping characteristics recommended by PPV & FRA. All the approaches clustered the improved landrace entities separately from the conventionally bred varieties. [ABSTRACT FROM AUTHOR]

The present study was carried out to evaluate 28 medicinal plants of Pakistan having folklore claims to neutralize coagulopathy induced by Naja naja karachiensis bite in comparison with standard antidote. Venom was tested on citrated human plasma to determine its effect on prothrombin time (PT), activated partial thromboplastin time (aPTT) and thrombin time (TT). Snake venom (200 µg/ml) was found to delay PT (13 ± 0.57 to 23 ± 0.57 sec), aPTT (35 ± 1.52 to 48 ± 2.0 sec) and TT (13 ± 0.57 to 33 ± 0.57 sec) within 4.5% coefficient of variance. Prolongation of PT and TT suggested the presence of thrombin-like or plasminogen activating enzymes. Methanolic plant extracts (5 µg/ml) were considered as effective standard antidote. Enicostemma hyssopifolium (Willd.) Verdoorn (PT = 22 ± 0.57 sec, aPTT = 36 ± 1.00 sec, TT = 19 ± 0.57 sec) and Stenolobium stans (L) D. Don (PT = 16 ± 0.57 sec, aPTT = 36 ± 0.57 sec, TT = 29 ± 0.57 sec) were considered the most protective (≽70%, but ≼ 92%) from the rest of the listed medicinal plants. Nevertheless, further studies are required for identification and segregation of bioactive constituent(s) as an alternate and cheap source to treat anticoagulation. [ABSTRACT FROM AUTHOR]

Highlights: [•] Chloroacetamides cause changes in human erythrocyte integrity and lipid peroxidation. [•] DEA and MEA do not cause any harmful effect on human erythrocytes. [•] Safeners do not produce any damage to erythrocytes. [•] Combination of safener with herbicide do not attenuate hemolysis of erythrocytes. [•] Safeners reduced lipid peroxidation induced by herbicides. [ABSTRACT FROM AUTHOR]

Plants adapt to abiotic stress by undergoing diverse biochemical and physiological changes that involve hormone-dependent signaling pathways. The effects of plant hormones can be mimicked by exogenous chemical regulators such as herbicide safeners, which not only enhance stress tolerance but also confer hormetic benefits such as increased vigor and yield. In this study, rice plants growing in normal and saline soils were exposed to abscisic acid (ABA), the safener cyprosulfamide or both compounds together. We found that cyprosulfamide, either alone or in combination with ABA, protected the plants from salinity stress and induced vigorous growth, including the formation of new tillers and early flowering. Proteomic analysis identified several proteins that were induced by stress and/or the chemical treatments, including the late embryogenesis abundant protein OsLEA3, a putative mitochondrial translocase and a putative fumarylacetoacetate hydrolase. The corresponding genes were induced by stress and/or the individual chemical treatments, but expression dropped back when the stress was removed. However, the combination of ABA and cyprosulfamide prolonged the expression of all three genes beyond the stress period, and allowed the plants to maintain their enhanced growth characteristics. These data support a model involving cooperation between the cyprosulfamide and ABA signaling pathways. Accordingly, it was found that cyprosulfamide induces ABA synthesis more robustly than salinity stress, allowing the two regulators to converge on certain downstream target genes. We discuss the impact of our results on current models for the hormonal regulation of stress response pathways in rice and other plants. [ABSTRACT FROM AUTHOR]

Abstract: Safeners are agrochemicals which enhance tolerance to herbicides in cereals including wheat (Triticum aestivum L.) by elevating the expression of xenobiotic detoxifying enzymes, such as glutathione transferases (GSTs). When wheat plants were spray-treated with three safener chemistries, namely cloquintocet mexyl, mefenpyr diethyl and fenchlorazole ethyl, an apparently identical subset of GSTs derived from the tau, phi and lambda classes accumulated in the foliage. Treatment with the closely related mefenpyr diethyl and fenchlorazole ethyl enhanced seedling shoot growth, but this effect was not determined with the chemically unrelated cloquintocet mexyl. Focussing on cloquintocet mexyl, treatments were found to only give a transient induction of GSTs, with the period of elevation being dose dependent. Examining the role of safener metabolism in controlling these responses, it was determined that cloquintocet mexyl was rapidly hydrolysed to the respective carboxylic acid. Studies with cloquintocet showed that the acid was equally effective at inducing GSTs as the ester and appeared to be the active safener. Studies on the tissue induction of GSTs showed that whilst phi and tau class enzymes were induced in all tissues, the induction of the lambda enzymes was restricted to the meristems. To test the potential protective effects of cloquintocet mexyl in wheat on chemicals other than herbicides, seeds were pre-soaked in safeners prior to sowing on soil containing oil and a range of heavy metals. Whilst untreated seeds were unable to germinate on the contaminated soil, safener treatments resulted in seedlings briefly growing before succumbing to the pollutants. Our results show that safeners exert a range of protective and growth promoting activities in wheat that extend beyond enhancing tolerance to herbicides. [Copyright &y& Elsevier]

Background Currently, the commercial formulations of the herbicide paraquat are highly toxic to humans, and no effective antidote is available for paraquat poisoning. The aim of the present study was to develop a safe formulation, combining paraquat and the known antidote lysine acetylsalicylate. The toxicity of a mixture of Gramoxone® (20% paraquat) and lysine acetylsalicylate in adult Wistar male rats and the herbicidal efficacy against grass lawn (50% of Poa pratensis and 50% of Festuca arundinacea) were evaluated. This new formulation was administered to Wistar rats by gavage at 125 mg kg−1 of paraquat ion and lysine acetylsalicylate at 79, 158 or 316 mg kg−1 body weight, and the survival rate was observed for 30 days. Results The survival rate of the paraquat group was only 40%, while lysine acetylsalicylate provided effective protection, with full survival observed in the groups that received 125 mg kg−1 of paraquat ion and 316 mg kg−1 of lysine acetylsalicylate. Both formulations of paraquat, either in the absence or in the presence of lysine acetylsalicylate, provided the same herbicidal activity against the tested herbal species. Conclusions The present formulation of paraquat containing lysine acetylsalicylate, significantly decreases mammalian toxicity while maintaining effective herbicidal activity. © 2012 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Herbal medicines are being used with greater frequency by practitioners of natural medicine in the United States. Many categories of herbs are used, primarily angiotensin antagonists, nonspecific nephroprotective, and immunomodulating/adaptogenic herbs. The most common herbs in each category are discussed both from a historical and scientific perspective. For the first time, a case series of the use of the proposed herbal angiotensin antagonist herb indigenous to the United States, Lespedeza capitata, is reported based on the author's clinical practice. [ABSTRACT FROM AUTHOR]

Safeners are so-called "inert" constituents of herbicide formulations added to protect crops from the toxic effects of herbicides. We examined the reactivity of three dichloroacetamide safeners and 12 structural analogues [all neutral compounds of the form Cl2CXC(═O)NRR'; X = H, Cl; R-groups include alkyl, branched alkyl, n-allyl, and cyclic moieties] in one homogeneous and two heterogeneous reductant systems: solutions of Cr(H2O)62+, suspensions of FeII-amended goethite, and suspensions of FeII-amended hematite. Analyses of reaction products indicate each safener can undergo stepwise hydrogenolysis (replacement of chlorine by hydrogen) in each system at near-neutral pH. The first hydrogenolysis step generates compounds similar (in one case, identical) to herbicide active ingredients. Rates of product formation and (when reactions were sufficiently fast) parent loss were quantified; reaction rates in heterogeneous systems spanned 2 orders of magnitude and were strongly influenced by R-group structure. The length of n-alkyl R-groups exerted opposite effects on hydrogenolysis rates in homogeneous versus heterogeneous systems: as R-group size increased, reduction rates in heterogeneous systems increased, whereas reduction rates in the homogeneous system decreased. Branched alkyl R-groups decreased hydrogenolysis rates relative to their straight-chain homologues in both homogeneous and heterogeneous systems. Reaction rates in heterogeneous systems can be described via polyparameter linear free energy relationships employing molecular parameters likely to influence dichloroacetamide adsorption. The propensity of dichloroacetamide safeners to undergo reductive transformations into herbicide-like products challenges their classification as "inert" agrochemical ingredients. [ABSTRACT FROM AUTHOR]

L'utilisation de pesticides et l'introduction de variétés résistantes à certains bioagresseurs (insectes, champignons, virus, bactéries) en agriculture exercent une pression de sélection sur ces populations de bioagresseurs. Au cours du temps, l'efficacité de ces technologies peut diminuer si des résistances (aux pesticides ou aux variétés résistantes) se développent. La durabilité des pesticides et des variétés résistantes est donc en grande partie tributaire de leur utilisation. Plus une technologie est utilisée de façon systématique et intensive, plus la pression sélective est forte, plus vite le gène de résistance dans la population de bioagresseurs est sélectionné, et plus rapidement la technologie devient obsolète. La gestion durable des résistances requiert une utilisation parcimonieuse des moyens de prévention qui n'est pas nécessairement compatible avec les intérêts économiques à court terme des utilisateurs. D'un point de vue économique, la sensibilité des bioagresseurs aux pesticides (ou aux résistances variétales) est une ressource naturelle. Les stratégies de gestion durable des résistances ont pour but de l'extraire de manière optimale au cours du temps, c'est-à-dire de retarder le développement de l'adaptation de ces populations de bioagresseurs.1 Afin de contrôler le développement de la résistance aux pesticides, le « régulateur » a à sa disposition différents instruments de politique environnementale. Notre étude permet de mieux appréhender les déterminants de l'arbitrage entre deux de ces instruments, la zone refuge obligatoire et la taxe sur les pesticides ou sur les semences des variétés résistantes. Un modèle bio-économique spatialement et temporellement explicite est utilisé pour comparer la performance des deux instruments selon diverses hypothèses sur la mobilité des insectes ravageurs. Cette analyse se situe dans le prolongement d'un exercice antérieur pluridisciplinaire de simulations bio-économiques sur l'exemple de la pyrale du maïs (Vacher et al., 2007). [ABSTRACT FROM AUTHOR]

ABSTRACT Safeners enhance herbicide tolerance in crop plants but not in target weeds, thus improving herbicide selectivity. The safeners isoxadifen-ethyl and mefenpyr-diethyl protect cereal crops from sulfonyl urea herbicides in postemergence application. The two safeners were shown here to induce the cellular xenobiotic detoxification machinery in Arabidopsis thaliana when applied to leaves in a way mimicking field application. Gene expression profiling revealed the induction of 446 genes potentially involved in the detoxification process. Transgenic Arabidopsis plants expressing a reporter gene under control of a safener-responsive maize promoter were used as a model system to study the safener signalling pathway. Reporter gene analysis in the tga2/3/5/6, sid2-2 and npr1 mutants as compared with the wild-type background showed that safener inducibility required TGA transcription factors and salicylic acid (SA) in a NON-EXPRESSOR of PR-1 (NPR1)-independent pathway converging on two as-1 promoter elements. For the majority of the safener-responsive Arabidopsis genes, a similar dependence on TGA transcription factors and/or SA was shown by gene expression profiling in wild-type plants as compared with the tga2/3/5/6 and sid2-2 mutants. Thirty-eight percent of the genes, however, were induced by safeners in a TGA/SA-independent manner. These genes are likely to be controlled by WRKY transcription factors and cognate W-boxes in their promoters. [ABSTRACT FROM AUTHOR]