Safening effect of dimepiperate on root-growth inhibition in rice caused by bensulfuron methyl.

Shirakura, Shinichi; Yuyama, Takeshi; Ishizuka, Kôzô

doi:10.3719/weed.33.271

Cited by 8 publications

(11 citation statements)

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“…Bensulfuron-methyl is rapidly detoxified in rice by hydroxylation of one of the two methoxy groups fixed to the pyrimidine heterocycle (Brown, 1990). From several other metabolites isolated and identified, an exhaustive metabolic pathway was proposed (Beyer et al, 1988;Shirakura et at, 1988) which also suggested the breakdown of the urea bridge and hydrolysis of the ester substituent of the molecule.…”

Section: Chlorimuron Ethylmentioning

confidence: 99%

Alcoholysis and chemical hydrolysis of bensulfuron‐methyl

Sabadie

1996

Weed Research

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Summary Alcoholysis (methanol or ethanol) and hydrolysis (pH ≤ 8) of the herbicide bensulfuron‐methyl at 30 or 50^C involve only the breakdown of the urea part of the molecule. A high yield of the pyrimidinamine is always obtained, along with the corresponding carbamate (alcoholysis) or benzylsulfonamide (hydrolysis). The latter compound was easily cyclized (pH ≥ 6). In alkaline solution, the carbomethoxy substituent of the aromatic ring was preferentially hydrolysed. In all cases, the alcoholysis and hydrolysis rates could be described well with first‐order kinetics. Alcoholysis rate constants of bensulfuron‐methyl and bensulfuron ranged from 0.08 to 0.15 d−1 at 30^C. Hydrolysis rate constants of bensulfuron‐methyl, bensulfuron and benzylsulfonamide varied strongly with pH. The hydrolysis rate constant of bensulfuron‐methyl was minimal around pH 8. The hydrolysis rate constant of bensulfuron decreased with increasing pH, whereas that of benzylsulfonamide increased with increasing pH.

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Section: Chlorimuron Ethylmentioning

confidence: 99%

Alcoholysis and chemical hydrolysis of bensulfuron‐methyl

Sabadie

1996

Weed Research

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“…may be dependent on cytochrome P-450 reactions (Shim et al 1990b). Dymron may display safening effects partially by enhancing the metabolism of not only a sulfonylurea herbicide, but also a chloroacetamide herbicide via enhancing cytochrome P-450 activity, as well as dimepiperate (Nishizaka et al 1991;Shirakura et al 1988Shirakura et al , 1996Yun et al 1999). Dymron is also known to reduce the uptake of bensulfuron-methyl by rice seedlings .…”

Section: Concentrationmentioning

confidence: 99%

“…Since the development and use of the first systematic screening program credited to identifying chemical crop safeners for selected herbicides, many safeners today have been discovered and commercialized (Hatzios & Hoagland 1988). Among them (safeners), the chloroacetamide safeners of corn against thiocarbamate and chloroacetamide heribicide injury have been the most successful, and a combined application of a sulfonylurea herbicide and another herbicide such as urea or thiocarbamate herbicide is also effective for safening action in paddy rice (Sweetser 1985; Shirakura et al 1988; Lee et al 1992). Safeners are known to affect several enzyme systems and processes, including GST, glutathione reductases, sulfur assimilation, and cytochrome P‐450 mono‐oxygenases.…”

Section: Introductionmentioning

confidence: 99%

Relationship between safening activity of dymron and fenclorim to pretilachlor and glutathione S‐transferase activity in rice

Deng

Yamada

Usui

2001

Weed Biology and Management

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Dymron [1‐(α,α‐dimethybenzyl)‐3‐(p‐tolyl)urea] and fenclorim (4,6‐dichloro‐2‐phenylpyrimidine) were found to exhibit a safening activity on the growth of rice (Oryza sativa L.) seedlings against pretilachlor [2‐chloro‐2′,6′diethyl‐N‐(2‐propoxyethyl)acetanilide] injury. By pretilachlor treatment at 10–6 and 10–5 mol L–1, the elongation of the third leaves of rice seedlings was reduced by approximately 20 and 40%, and that of the fourth leaves was reduced by approximately 40 and 80%, respectively. Upon the treatment of dymron at 3 × 10–6 and 10–5 mol L–1 in combination with pretilachlor, the growth inhibition was half alleviated in the third leaves, and the length of the fourth leaves was almost recovered from 10–6 mol L‐1 pretilachlor injury, and was 20–25% recovered from 10–5 mol L–1 pretilachlor injury. Upon the treatment of fenclorim at 3 × 10–6 and 10–5 mol L–1 in combination with pretilachlor, the growth inhibition of rice seedlings was almost alleviated in both the third and the fourth leaves. This result indicated that dymron and fenclorim showed almost the same safening effect on the fourth leaf growth against 10–6 mol L‐1 pretilachlor injury, although fenclorim showed higher effects at higher concentrations of pretilachlor. Glutathione S‐transferase (GST) activities in rice seedlings were investigated after being treated with a herbicide and safener. By pretilachlor treatment at 10–6 and 10–5 mol L–1, the GST activity was approximately 32 and 72% increased in roots, respectively, and a little increased (7–13%) in shoots of two‐leaf‐stage rice seedlings. By dymron treatment at 3 × 10–6−10–5 mol L–1, the GST activity was 2–30% increased in roots, but was not increased in shoots. By their combination treatment, the GST activity was almost the same or less than that by treatment with pretilachlor alone. In contrast, by fenclorim treatment alone, the GST activity was 43–52 and 33–45% increased in roots and shoots of rice seedlings, respectively. By the combination treatment of pretilachlor and fenclorim, the GST activity was increased 73–126% in shoots and 101–139% in roots, and was much more increased in both shoots and roots compared with treatment of pretilachlor or fenclorim alone. It was found that dymron showed less effect in increasing the GST activity than fenclorim. It is also suggested that dymron did not increase the GST activity in shoots but did increase it slightly in roots, and showed almost no effect on GST increase by pretilachlor in shoots, or rather reduced the increase in roots. From the above results, fenclorim and dymron may have different mechanisms of safening effects on the protection of rice seedlings against pretilachlor injury.

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“…Bensulfuron‐methyl is rapidly detoxified in rice by hydroxylation of one of the two methoxy groups substituted in the pyrimidine heterocycle 6. Several other metabolites have been isolated and identified, and an exhaustive metabolic pathway was proposed which also suggested the breakdown of the urea bridge and hydrolysis of the ester substituent of the molecule 2, 7…”

Section: Introductionmentioning

confidence: 99%

Photodegradation of bensulfuron‐methyl on soil surface

Yue

Huai-man

et al. 2003

Pest Management Science

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Photolysis of bensulfuron-methyl on soil surface was studied under sunlight and UV light. Seven photoproducts were isolated and characterised by spectroscopic methods. The major processes in the photolysis of bensulfuron-methyl in soil are cleavage of the sulfonylurea bridge, scission of the SO2NH bond and contraction of the sulfuronylurea bridge. The rates of photodegradation of bensulfuron-methyl on different soils followed first-order rate kinetics with half lives of 21.9, 28.4, 36.9, 59.2 and 47.2 h (UV) and 23.1, 27.5, 29.1, 38.9 and 33.8 days (sunlight) for vertisol, alluvial, alfisol, red and laterite soils, respectively. The differences in rates of photodegradation were dependent upon the soil texture and organic matter content.

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Safening effect of dimepiperate on root-growth inhibition in rice caused by bensulfuron methyl.

Cited by 8 publications

References 0 publications

Alcoholysis and chemical hydrolysis of bensulfuron‐methyl

Alcoholysis and chemical hydrolysis of bensulfuron‐methyl

Relationship between safening activity of dymron and fenclorim to pretilachlor and glutathione S‐transferase activity in rice

Photodegradation of bensulfuron‐methyl on soil surface

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