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BACKGROUND Paraquat is used widely as one of the bipyridine herbicides, which generates reactive oxygen species to cause cell death. With a growing number of paraquat‐resistant weeds, the mechanism of paraquat‐resistance in plants remains unclear. This research verified the functions of a previously confirmed putative paraquat‐resistant gene, EiKCS, from paraquat‐resistant goosegrass by genetic engineering in a single overexpressing line in rice. RESULTS: Overexpression of EiKCS improved paraquat resistance in transgenic rice (KCSox). Pre‐applied (12 h) exogenous spermidine (1.5 mmol L−1), alleviated the injury of paraquat in rice. Paraquat induced injury in KCSox was 19.57%, which was lower than 32.22% injury it induced in wild‐type (WT) rice. The paraquat‐resistant mechanism was through the increased activity of antioxidant enzymes and the overproduction of endogenous polyamines. The spermine content in KCSox was more than 30 μg mL−1, while that in WT rice was less than 5 μg mL−1. Quantitative proteomics showed that β‐ketoacyl‐coenzyme A (CoA) synthase (51.81 folds) encoded by the transgenic EiKCS gene promoted the synthesis of the proteins involved with the polyamine pathway. The synthesized putrescine was promoted by the arginine decarboxylase (ADC) pathway. The spermidine synthase I (1.10‐fold) and three eceriferum cofactors (CERs) were responsive to the paraquat stress. We validated putrescine (C18H20N2O2) spermidine (C28H31N3O3), and spermine (C38H42N4O4) in this study. CONCLUSION: EiKCS encoding β‐ketoacyl‐CoA synthase from goosegrass has been shown as an ideal candidate gene for engineering genetically modified organism (GMO) crops, as its overexpression does not only bring paraquat‐resistance, but also have potential benefits without decreasing yield and rice grain quality. © 2021 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

A catalyst consisting of phosphotungstic acid (H3PW12O40) combined with activated clay was prepared by the impregnation method, and an experiment was carried out to evaluate the catalytic activity of the H3PW12O40/activated clay for the degradation of methyl orange (MO) in the UV–H2O2 process. The degradation ratio of MO can be affected by H2O2 concentration, reaction time, catalyst dosage, pH and temperature. The reaction temperature should be controlled at less than 70 °C, and the catalyst has a wide applicable pH range in the UV–H2O2 process. Hydroxyl radicals were generated in the UV–H2O2 system under the action of H3PW12O40/activated clay, and MO was degraded by hydroxyl radicals. Compared with traditional catalysts used in UV–H2O2 systems, H3PW12O40/activated clay has certain advantages for its practical application. [ABSTRACT FROM PUBLISHER]

Background: Paraquat is used widely as one of the bipyridine herbicides, which generates reactive oxygen species to cause cell death. With a growing number of paraquat-resistant weeds, the mechanism of paraquat-resistance in plants remains unclear. This research verified the functions of a previously confirmed putative paraquat-resistant gene, EiKCS, from paraquat-resistant goosegrass by genetic engineering in a single overexpressing line in rice., Results: Overexpression of EiKCS improved paraquat resistance in transgenic rice (KCSox). Pre-applied (12 h) exogenous spermidine (1.5 mmol L -1 ), alleviated the injury of paraquat in rice. Paraquat induced injury in KCSox was 19.57%, which was lower than 32.22% injury it induced in wild-type (WT) rice. The paraquat-resistant mechanism was through the increased activity of antioxidant enzymes and the overproduction of endogenous polyamines. The spermine content in KCSox was more than 30 μg mL -1 , while that in WT rice was less than 5 μg mL -1 . Quantitative proteomics showed that β-ketoacyl-coenzyme A (CoA) synthase (51.81 folds) encoded by the transgenic EiKCS gene promoted the synthesis of the proteins involved with the polyamine pathway. The synthesized putrescine was promoted by the arginine decarboxylase (ADC) pathway. The spermidine synthase I (1.10-fold) and three eceriferum cofactors (CERs) were responsive to the paraquat stress. We validated putrescine (C 18 H 20 N 2 O 2 ) spermidine (C 28 H 31 N 3 O 3 ), and spermine (C 38 H 42 N 4 O 4 ) in this study., Conclusion: EiKCS encoding β-ketoacyl-CoA synthase from goosegrass has been shown as an ideal candidate gene for engineering genetically modified organism (GMO) crops, as its overexpression does not only bring paraquat-resistance, but also have potential benefits without decreasing yield and rice grain quality. © 2021 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry., (© 2021 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.)

A catalyst consisting of phosphotungstic acid (H3PW12O40) combined with activated clay was prepared by the impregnation method, and an experiment was carried out to evaluate the catalytic activity of the H3PW12O40/activated clay for the degradation of methyl orange (MO) in the UV-H2O2 process. The degradation ratio of MO can be affected by H2O2 concentration, reaction time, catalyst dosage, pH and temperature. The reaction temperature should be controlled at less than 70 degrees C, and the catalyst has a wide applicable pH range in the UV-H2O2 process. Hydroxyl radicals were generated in the UV-H2O2 system under the action of H3PW12O40/activated clay, and MO was degraded by hydroxyl radicals. Compared with traditional catalysts used in UV-H2O2 systems, H3PW12O40/activated clay has certain advantages for its practical application.