共查询到17条相似文献，搜索用时 250 毫秒
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除草剂安全剂的生理生化作用机制研究进展 总被引：9，自引：0，他引：9
除草剂安全剂是一种化学物质,它可以通过生理或生化的途径降低除草剂对作物的毒性,而不降低除草剂的功效.安全剂影响作物的吸收和传导,诱导作物体内P450酶活性、谷胱甘肽调控及其靶标酶ALS的活性.其生理和生化机制研究,不仅有助于安全剂的开发和优化,同时也是了解和运用除草剂活性和抗性机制的途径.该文综述了近年来国内外安全剂生理生化作用机制的研究进展,并探讨其研究方向. 相似文献
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除草剂安全剂作用机理研究进展 总被引：4，自引：0，他引：4
除草剂安全剂是一类可在不影响除草剂对靶标杂草活性的前提下,有选择性地保护作物免受除草剂伤害的特殊用途化合物,有关安全剂作用机理的研究对新安全剂的开发具有重要意义。目前关于除草剂安全剂的作用机理主要有4种观点:1）影响除草剂在作物体内的吸收和转运;2）与除草剂竞争靶标位点;3）影响靶标酶的活性;4）增强作物对除草剂的代谢。文章对近年来安全剂作用机理及安全剂对杂草的影响等研究进展进行了综述,并分析了当前存在的问题及未来的研究方向,旨在为深入研究安全剂的作用机理及新安全剂开发提供参考。 相似文献
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除草剂药害是除草剂实际使用过程中难以回避的问题，解决除草剂药害问题最为直接且有效的方法是使用除草剂安全剂。除草剂安全剂是一类选择性保护作物免受除草剂药害而不影响除草剂对靶标杂草除草活性的农用化学品。目前已发现一些商品化安全剂在长期使用过程中对农业生态环境存在一定风险。天然产物除草剂安全剂是来源于动植物及微生物体内的内源性化合物，由于其结构新颖且对生态环境相对友好，因此以其为除草剂安全剂有望解决商品化安全剂对环境存在潜在风险的问题。本文综述了以天然产物作为除草剂安全剂在发掘方法、结构与种类、缓解除草剂对作物药害效果等方面的研究进展，归纳了现有天然产物安全剂保护作物免受除草剂药害的作用机理；总结和展望了天然产物安全剂在田间推广应用的局限性以及今后的研究方向，可为该类安全剂在防范除草剂药害的实际应用以及相应产品的研发提供指导。 相似文献
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大多数除草剂都是通过特殊酶的抑制而产生杀草作用的。因此,以靶标进行分子设计,鉴定化合物分子结构中的活性团,开发能有效杀死杂草、而不伤害作物并对动物及环境安全的除草剂品种有着重要意义。本文着重对各种不同类型靶标酶在除草剂的研究与开发过程中的应用加以阐述。 相似文献
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To investigate the selectivity and safening action of the sulfonylurea herbicide pyrazosulfuron‐ethyl (PSE), pyrazosulfuron‐ethyl O‐demethylase (PSEOD) activity involving oxidative metabolism by cytochrome P‐450 was studied in rice (Oryza sativa L cv Nipponbare) and Cyperus serotinus Rottb. Cytochrome P‐450‐dependent activity was demonstrated by the use of the inducers 1,8‐naphthalic anhydride and ethanol, the herbicides PSE, bensulfuron‐methyl, dimepiperate and dymron, or the inhibitor piperonyl butoxide (PBO). Growth inhibition in C serotinus seedlings was more severe than that in rice seedlings. O‐Dealkylation activities of PSE were induced differently in rice and in C serotinus, with distinctly higher activity in rice seedlings. The induced PSEOD activities were slightly inhibited by PBO in rice seedlings, whereas they were strongly inhibited in C serotinus seedlings. Dimepiperate and dymron were effective safeners of rice against PSE treatment. Treatments with herbicide alone resulted in less induction of PSEOD activity compared with combined treatments of the herbicide and safener. PSEOD activity in rice seedlings induced with herbicide alone was strongly inhibited by PBO, whereas it was weakly inhibited in rice seedlings induced with combinations of PSE and two safeners. These results suggest that O‐demethylation by cytochrome P‐450 enzymes may be involved in the metabolism of PSE and may contribute to its selectivity and safening action. Furthermore, these results suggest the existence of a multiple form of cytochrome P‐450 in plants. © 2001 Society of Chemical Industry 相似文献
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Herbicide safeners selectively protect crop plants from herbicide damage without reducing activity in target weed species. This paper provides an outline of the discovery and uses of these compounds, before reviewing literature devoted to defining the biochemical and physiological mechanisms involved in safener activity. Emphasis is placed on the effects of safeners on herbicide metabolism and their interactions with enzyme systems, such as cytochrome P450 mono-oxygenases and glutathione-S-transferases. Attention is drawn to the potential wide-ranging applications of safeners and, in particular, their use as powerful research tools with which to identify and manipulate those mechanisms which contribute to herbicide selectivity and resistance. © 1999 Society of Chemical Industry 相似文献
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C. FEDTKE 《Weed Research》1987,27(3):221-228
inhibitory activities of existing graminicides on root regeneration from monocotyledonous (oat) and dicotyledonous (soybean) plant cuttings in the light, in the dark and on algal growth were compared with the respective inhibitory activities of the new herbicide 2-(2-benzothiazo-lyl-oxy)-N-methyl-N-phenylacetamide (mefenacet). The mefenacet activity spectrum resembled that of the α-chloroacetamide herbicides. Herbicide groups of other structure-activity can be distinguished by their distinct activity spectrum. The mono-oxygenase inhibitors piperonyl but-oxide (PBO) and 1-aminobenzotriazole (ABT) were found to antagonize the inhibitory activities of herbicides from the thiolcarbamate, α-chloroacetamide, and oxyacetic acid amide structure groups in the oat rooting and leaf growth tests. The critical evaluation of the presently available information on graminicide and safener mode of action suggests the concept that lipid biosynthesis on the physiological level and mono-oxygenase type enzymes on the biochemical level may hold the target sites for many of the graminicides and safeners discussed. 相似文献
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Theodoulou FL Clark IM He XL Pallett KE Cole DJ Hallahan DL 《Pest management science》2003,59(2):202-214
Herbicide safeners are known to protect monocotyledonous crops from herbicide injury by accelerating the metabolism of herbicides. We have investigated the effects of the safener cloquintocetmexyl, which protects small-grain cereals against the graminicidal herbicide, clodinafop-propargyl. Subtractive suppression hybridisation was used to identify wheat genes which are up-regulated by treatment not only with cloquintocet-mexyl but also with phenobarbital, which is known to stimulate xenobiotic metabolism in animals and plants. DNA sequences of five glutathione transferases (GSTs) belonging to three different classes and a multidrug resistance associated protein (MRP) homologue were identified in the screen. The chemical inducibility of these clones was confirmed by Northern analysis. The MRP protein was shown to be induced by treatments with cloquintocet-mexyl and phenobarbital and to be localised to the tonoplast. Since clodinafop-propargyl is not known to be metabolised by glutathionylation, the significance of GST induction is interpreted in terms of a generalised response to chemical stress, particularly the generation of active oxygen species. This work establishes herbicide safeners as useful tools for the identification of genes encoding herbicide-metabolising enzymes. 相似文献
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The ability of the herbicide safeners, BAS-145138 (1-dichloroacetyl-hexahydro-3,3,8a-trimethyl-pyrrolo(1,2a)pyrimidin-6(2H)-one), dichlormid (N,N-diallyl-2,2-dichloroacetamide), flurazole (phenylmethyl ester), and MG-191 (2-dichloromelhyl-2-methyl-1,3-dioxolane) for preventing metazachlor injury to maize (Zea mays L.) and sorghum (Sorghum bicolor L.) seedlings were compared with their effects on 14C-metazachlor metabolism to a glutathione (GSH) conjugate, effects on non-protein thiol contents (mainly GSH) and effects on Glutathione S-transferase (GST) activity in these two species. Sorghum shoot growth was reduced by 41% and maize shoot growth was reduced by 54%, by metazachlor concentrations in vermiculite nutrient culture of 0·6 μM and 7·5μM, respectively. In this system, all four compounds had significant activity as safeners for metazachlor in both sorghum and maize seedlings. BAS-145138 and flurazole were the most effective safeners in maize and sorghum, respectively. In the absence of safeners, the rate of non-enzymatic conjugation of metazachlor and GSH was much greater than the enzymatic rate. However, the rate of enzymatic conjugation of metazachlor with GSH was increased by safener treatment in both maize and sorghum. Safener effectiveness was highly correlated with increases in 14C-metazachlor uptake and metabolism in both species. Safener effectiveness was more highly correlated with safener effects on GST activity in maize or sorghum when 14C-metazachlor was used as the substrate than when the non-specific CDNB (1-chloro-2,4-dinitrobenzene) was used as the substrate. Safener effectiveness was also strongly correlated with safener effects on GSH levels in sorghum, but not in maize, possibly because of the greater importance of non-enzymatic conjugation of metazachlor with GSH in sorghum as compared to maize. 相似文献