Herbicide resistance in transgenic plants with mammalian P450 monooxygenase genes

Inui, Hideyuki; Ohkawa, Hideo

doi:10.1002/ps.1012

Cited by 62 publications

(23 citation statements)

References 20 publications

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“…In one of the experiments, a fusion protein between the rat CYP1A1 and yeast NADPH:P450 reductase conferred chlortoluron resistance to tobacco (Shiota et al 1994). The human CYP1A1, CYP2B6, CYP2C9 and CYP2C19 cDNAs were used either separately or in combination to transform rice and potato (reviewed in Inui and Ohkawa 2005;Hirose et al 2005;Kawahigashi et al 2005a). Enhanced resistance to a wide range of herbicides including atrazine, acetochlor, metolachlor, chlorsulfuron, imazosulfuron, chlortoluron, methabenzthiazuron, norflurazon, mefenacet and pyributicarb, was shown to be a result of elevated herbicide metabolism.…”

Section: Herbicide Detoxifying P450s Isolated From Nonplant Sourcesmentioning

confidence: 99%

Plant cytochrome P450-mediated herbicide metabolism

2006

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In the last two decades it has become apparent that enzymes of the P450 monooxygenase (P450) superfamily are responsible for the Phase I metabolism of numerous herbicides representing several classes of organic compounds. The majority of experimental evidence for P450 involvement in herbicide metabolism has been derived from in vitro studies in which the catalytic activity of plant microsomes towards herbicidal substrates was measured in the presence of various P450 inhibitors and activators. While the studies with microsomes elicited much appreciation for the pivotal roles of plant P450s in herbicide metabolism, detailed characterization of these enzymes only became possible after the isolation of genes encoding specific isoforms responsible for herbicide conversion. Several lines of evidence suggest that the development of herbicide resistance in weeds by enhanced detoxification is frequently associated with elevated levels of P450 activity. Enhanced detoxification-based herbicide resistance is particularly difficult to control, because it can involve resistance to multiple, chemically unrelated classes of herbicides. Continued research efforts are aimed at elucidating the role of P450s in the metabolic fates of herbicides in plants and the development of herbicide resistance in weeds. Recent advances made in the isolation and genetic manipulation of P450 enzymes have created new opportunities for their application in engineering herbicide tolerance and bioremediation.

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Section: Herbicide Detoxifying P450s Isolated From Nonplant Sourcesmentioning

confidence: 99%

Plant cytochrome P450-mediated herbicide metabolism

2006

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“…Cytochrome P450 monooxygenases are known to play a role in detoxifying xenobiotics and degrading pesticides in plants. Japanese scientists enhanced the degradation of sulfonylurea herbicides in rice plants by incorporating genes that enhanced the production of a P450 monooxygenase (Inui and Ohkawa 2005). Varsano et al (1992) showed that if P450 monooxygenase deliberately was inhibited in maize plants, their susceptibility to triazine herbicides increased (Varsano et al 1992).…”

Section: Introductionmentioning

confidence: 98%

“…The insecticides malathion, endosulfan and chlorpyrifos were chosen due to their occurrence in surface waters (Van Wijngaarden et al 2005;Tauler et al 2001;Pedersen et al 2006;Barlas et al 2006), while the herbicides metsulfuron-methyl, terbuthylazine and bentazone were chosen as representatives for herbicide classes whose metabolism had been shown to be affected by P450 monooxygenases (Varsano et al 1992;Baerg et al 1996;Inui and Ohkawa, 2005;Moreland et al 1993). The experiments were carried out on the two aquatic species Pseudokirchneriella subcapitata and Lemna minor.…”

Section: Introductionmentioning

confidence: 99%

Organophosphorous insecticides as herbicide synergists on the green algae Pseudokirchneriella subcapitata and the aquatic plant Lemna minor

2007

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Models proposed for risk assessment of chemical mixtures assume no interactions between the chemicals. There are, however, studies indicating that some organophosporous insecticides can inhibit the detoxification of other chemicals in plants thereby enhancing their effect. The present study investigates whether interactions between selected organophosporous insecticides and herbicides can take place in the aquatic algae Pseudokirchneriella subcapitata and the aquatic macrophyte Lemna minor. For both species binary mixtures of the organophosphate insecticides: malathion, endosulfan and chlorpyrifos were tested together with the herbicides metsulfuron-methyl, terbutylazine and bentazone. For mixtures with malathion on algae, dose-response surfaces were made and the results tested against the model of concentration addition (CA) and independent action (IA). The Lemna minor tests showed no indication of synergy for any of the combinations, on the contrary, significant antagonism was found for several of the mixtures. The response surface analysis showed antagonism in relation to both concentration addition and independent action for mixtures between malathion and metsulfuron-methyl and terbuthylazine, while the mixtures with bentazone could be explained with CA. The study shows no indications of synergistic interactions between the tested pesticides, confirming the applicability of CA as a reference model predicting mixture effects of pesticides for aquatic plants and algae.

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“…All these systems require the co-expression of NADPH-P450 reductase in order to obtain catalytically active P450s. Overexpression of mammalian P450 isozymes in plants, e.g., tobacco, was shown to enhance the oxidative metabolism of, e.g., herbicides [8]. Co-expression of mammalian NADPH-P450 reductase was not necessary, since the foreign P450s were supplied with requisite electrons by endogenous plant reductases.…”

mentioning

confidence: 99%

Comparison of the Biotransformation of the14C-Labelled Insecticide Carbaryl by Non-Transformed and Human CYP1A1-, CYP1A2-, and CYP3A4-Transgenic Cell Cultures ofNicotiana tabacum

Schmidt¹,

Faymonville²,

Gembé³

et al. 2006

C&B

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Transgenic tobacco-cell-suspension cultures expressing separately the human cytochrome P450 monooxygenases CYP1A1, CYP1A2, and CYP3A4 were utilized to study the biotransformation of the 14C-labelled insecticide carbaryl (=naphthalen-1-yl methylcarbamate). The resulting data were compared to similar data from the corresponding non-transformed (NT) tobacco-cell culture and commercially available membrane preparations (Bactosomes) of genetically modified bacteria separately containing the same human P450s. A rapid conversion rate of carbaryl was observed with the CYP1A1 and CYP1A2 cells, where only 49.7 and 0.2% of applied carbaryl (1 mg/l), respectively, remained after 24 h, as compared to 77.7% in the non-transformed culture. Unexpectedly, the corresponding results obtained from the CYP3A4 cultures were not definite. With 25 mg/l of carbaryl and 96 h of incubation, it was proven that the insecticide is also substrate of CYP3A4. This finding was supported by GC/EI-MS analysis of the primary metabolite pattern produced by the isozyme. This consisted of naphthalene-1-ol, N-(hydroxymethyl)carbaryl, 4-hydroxycarbaryl, and 5-hydroxycarbaryl, whereas the main product in non-transformed cells was N-(hydroxymethyl)carbaryl. Data obtained from the CYP1A1, CYP1A2, or CYP3A4 Bactosomes agreed with those of the P450-transgenic tobacco cells. Problems with GC/EI-MS analysis of carbaryl and its metabolites are discussed.

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Herbicide resistance in transgenic plants with mammalian P450 monooxygenase genes

Cited by 62 publications

References 20 publications

Plant cytochrome P450-mediated herbicide metabolism

Plant cytochrome P450-mediated herbicide metabolism

Organophosphorous insecticides as herbicide synergists on the green algae Pseudokirchneriella subcapitata and the aquatic plant Lemna minor

Comparison of the Biotransformation of the14C-Labelled Insecticide Carbaryl by Non-Transformed and Human CYP1A1-, CYP1A2-, and CYP3A4-Transgenic Cell Cultures ofNicotiana tabacum

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