Studies of clomazone mode of action

Ferhatoglu, Yurdagul; Barrett, Michael

doi:10.1016/j.pestbp.2005.10.002

Cited by 105 publications

(100 citation statements)

References 44 publications

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“…In addition, Ferhatoglu and Barrett demonstrated that 20 mM ketoclomazone inhibited 47% of DXP synthase activity in crude extracts from E. coli expressing a plant Catharanthus roseus DXP synthase gene. 23 These reports have suggested that clomazone may be converted into ketoclomazone in plants to inhibit DXP synthase. However, a mechanism of inhibition by ketoclomazone of DXP synthase has not been elucidated, although clomazone and ketoclomazone have been used as chemical tools to suppress the MEP pathway in plants.…”

Section: Introductionmentioning

confidence: 99%

The herbicide ketoclomazone inhibits 1-deoxy-D-xylulose 5-phosphate synthase in the 2-C-methyl-D-erythritol 4-phosphate pathway and shows antibacterial activity against Haemophilus influenzae

et al. 2010

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Two distinct metabolic pathways have been elucidated for the formation of isopentenyl diphosphate and dimethylallyl diphosphate, essential metabolic precursors for isoprenoid biosynthesis: the mevalonate pathway, found ubiquitously in mammals, and the 2-C-methyl-D-erythritol 4-phosphate (MEP) pathway, found in most bacteria. As the MEP pathway is absent from mammals, all MEP pathway enzymes represent effective targets for the development of antibacterial drugs. In this study, we found that a herbicide, ketoclomazone, exhibited antibacterial activity against a pathogenic bacterium, Haemophilus influenzae, with an MIC value of 12.5 lg ml À1 and that antibacterial activity was suppressed by adding 1-deoxyxylulose, a free alcohol of 1-deoxy-D-xylulose 5-phosphate (DXP). DXP is an MEP pathway intermediate synthesized from pyruvate and D-glyceraldehyde 3-phosphate (D-GAP) by the action of DXP synthase. Thus, we investigated the enzyme kinetics of DXP synthase of H. influenzae (HiDXS) to elucidate an inhibitory mechanism of ketoclomazone on HiDXS. The dxs gene was cloned from H. influenzae and overexpressed in Escherichia coli, and the enzyme was purified to homogeneity. The purified HiDXS was a soluble dimeric 70-kDa protein. Steady-state kinetic constants for HiDXS were calculated, and Lineweaver-Burk plots were consistent with a ping-pong bi bi mechanism. The kinetics of inhibition by ketoclomazone suggested that ketoclomazone binds to an unidentified inhibitor-binding site that differs from both the pyruvate-binding site and the D-GAP-binding site on DXP synthase. These data reveal the inhibitory mechanism of ketoclomazone on DXP synthase.

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Section: Introductionmentioning

confidence: 99%

The herbicide ketoclomazone inhibits 1-deoxy-D-xylulose 5-phosphate synthase in the 2-C-methyl-D-erythritol 4-phosphate pathway and shows antibacterial activity against Haemophilus influenzae

et al. 2010

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“…The pre-herbicide clomazone needs to be converted in the active metabolite 5-cetoclomazone (Dayan and Watson, 2011) to then inhibit 1-deoxy-D-xylulose-5-phosphate synthase (Ferhatoglu and Barrett, 2006), at methylerithritol phosphate pathway (MEP) of production of isoprenoids, synthesized in chloroplasts (Eisenreich et al, 2004), resulting in the reduction of carotene and phytol levels and, consequently, chlorophyll levels (Timossi and Alves, 2001). Since the carotenoids also have a protecting role in the photosystems, by dissipating the excess of chlorophyll energy in the excited state, the herbicide action needs to equally have a flow of electrons in the photosystems.…”

Section: Resultsmentioning

confidence: 99%

Electrolyte Leakage and the Protective Effect of Nitric Oxide on Leaves of Flooded Rice Exposed to Herbicides

Silva¹,

Urban²,

Balbinot³

et al. 2016

Planta daninha

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-The nitric oxide acts on the antioxidant system of plants and can discontinue the damage of herbicides elicitors of oxidative stress that cause the disruption of membranes and leakage of cellular contents. In order to evaluate the protective effect of nitric oxide in electrolytes leakage, leaf segments of the Puita INTA CL rice cultivar were incubated with 0, 5, 50, 500 and 5,000 μM clomazone (360 g a.i. L -1 ), oxadiazon (250 g a.i. L -1 ), oxyfluorfen (240 g a.i. L -1 ) and the formulated mixture of paraquat (200 g a.i. L -1 ) + diuron (100 g a.i. L -1 ) to obtain the maximum potential conductivity of 50% (MPC 50 ). Subsequently, leaf segments were pre-treated with 0, 200 and 2,000 μM of sodium nitroprusside (SNP) for four hours and further incubated for 48 hours with 0, 0.5, 1, 2 and 4 times the concentration of the herbicide that caused the CMP 50 , and the protective effect was reassessed in the presence of nitric oxide scavenger, cPTIO. The MPC 50 was caused by exposure to 188.9, 273.4, 410.2 + 205.1 and 917.0 μM of Oxadiazon, Oxyfluorfen, Paraquat + Diuron and Clomazone. Pretreatment with 200 μM of SNP reduced electrolyte leakage in leaf segments exposed to 2 and 4 times the MPC 50 to oxadiazon and paraquat + diuron, while 2,000 μM reduced the damage caused by oxyfluorfen, at the same concentrations. Also, 200 and 2,000 μM of SNP were efficient for clomazone, and the protection was confirmed by cPTIO in all cases.Keywords: Oryza sativa, sodium nitroprusside, clomazone, oxadiazon, oxyfluorfen, paraquat + diuron. 188,9; 273,4; 410,2 + 205,1; e 917,0 RESUMO -O óxido nítrico atua no sistema antioxidante das plantas e pode conter o dano de herbicidas

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“…Essa seletividade é alcançada pela inibição de uma enzima específica da citocromo P-450 mono-oxigenase, enzima esta responsável pela oxidação do clomazone, e não ocorre conversão do clomazone em 5-cetoclomazone, o qual confere Efeito do protetor dietholate na seletividade de clomazone ... ação herbicida às plantas suscetíveis (Ferhatoglu et al, 2006).…”

Section: Resultsunclassified

“…Com sua ação, as folhas das plantas sensíveis tornam-se brancas, sendo sintoma característico desse grupo de herbicidas (Senseman, 2007). Sua ação específica envolve a inibição da enzima deoxixilulose fosfato sintase (DXP sintase), responsável pela síntese de isoterpenoides, precursores básicos dos carotenoides, numa rota alternativa, denominada rota metilerithritol 4-fosfato (MEP), que ocorre no cloroplasto (Ferhatoglu et al, 2006). Devido às suas características físico-químicas, sua seletividade ao arroz irrigado é limitada em função da dose aplicada, do cultivar semeado (Sherder et al, 2004), do tipo de solo e do potencial de água no solo (Lee et al, 2004).…”

Section: Introductionunclassified

Efeito do protetor dietholate na seletividade de clomazone em cultivares de arroz irrigado

et al. 2010

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RESUMO -No arroz irrigado, o herbicida clomazone tem sua seletividade variável de acordo com o cultivar, o tipo de solo e a dose aplicada. O uso do protetor dietholate permite seletividade em diferentes ambientes, sendo necessário o estudo da relação entre esses fatores. Em vista do exposto, objetivou-se com este experimento quantificar a seletividade do herbicida clomazone em função de cultivares de arroz irrigado, tipos de solos, doses de clomazone e tratamento de sementes com dietholate. O experimento foi conduzido em casa de vegetação, em delineamento de blocos ao acaso, em esquema fatorial com quatro repetições. O fator A foi composto por tipos de solo (arenoso e argiloso); o fator B, por cultivares de arroz irrigado (IRGA 409 e IRGA 417); o fator C, pela ausência do protetor dietholate; e o fator D, por doses de clomazone (0, 156, 312, 625, 1.250, 2.500, 5.000 e 10.000 g ha -1 ) aplicadas em pré-emergência do arroz irrigado. Dezoito dias após a semeadura do arroz, foram avaliados a fitotoxicidade e o percentual de redução de massa fresca e seca da parte aérea das plantas de arroz. Os cultivares de arroz toleram maiores doses de clomazone quando tratados com dietholate e semeados em solos com maior teor de argila e matéria orgânica. Em solo arenoso, a toxicidade do herbicida nas plantas de arroz foi maior, na ordem de 50%, quando se comparou com a mesma dose em solo argiloso.Palavras-chave: IRGA 409, IRGA 417, Oryza sativa, protetor de plantas, tipos de solo.ABSTRACT -The selectivity of the herbicide Clomazone varies according to cultivar, soil type and rate applied, while the crop safener dietholate allows selectivity to occur under different conditions, making it necessary to study the relation between these factors. Thus, an experiment was conducted aiming to quantify Clomazone selectivity to rice cultivar, in two types of soil and with seeds treated and untreated with dietholate. The experiment was conducted under greenhouse conditions, and arranged in a randomized block design with four replications in a factorial scheme. Factor A included two rice cultivars, Factor B included seeds treated and untreated with dietholate, Factor C included two types of soil, and Factor D, eight rates of Clomazone (0, 156, 312, 625, 1,250, 2,500, 5,000 and 10,000 g ha -1 ). Plant injury and reduction percentage of fresh and dry mass weight of the aerial part of the rice plants were evaluated 18 days after sowing. The data were submitted to variance analysis. A difference (P d"0.05) was observed between the two types of soil and between the seeds treated with and without dietholate. The rice cultivars tolerate higher clomazone rates when treated with dietholate and sown in soil with higher clay and organic matter contents. In sandy soil, herbicide injury to the rice plants was 50% higher than in the clayey soil, when the same doses were compared.

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Studies of clomazone mode of action

Cited by 105 publications

References 44 publications

The herbicide ketoclomazone inhibits 1-deoxy-D-xylulose 5-phosphate synthase in the 2-C-methyl-D-erythritol 4-phosphate pathway and shows antibacterial activity against Haemophilus influenzae

The herbicide ketoclomazone inhibits 1-deoxy-D-xylulose 5-phosphate synthase in the 2-C-methyl-D-erythritol 4-phosphate pathway and shows antibacterial activity against Haemophilus influenzae

Electrolyte Leakage and the Protective Effect of Nitric Oxide on Leaves of Flooded Rice Exposed to Herbicides

Efeito do protetor dietholate na seletividade de clomazone em cultivares de arroz irrigado

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