共查询到19条相似文献，搜索用时 156 毫秒
1.
采用常规的室内生测和生化方法,开展新型除草剂丙酯草醚的作用机理研究.试验结果表明:同时添加5mg/L浓度的三种支链氨基酸即缬氨酸、亮氨酸和异亮氨酸能完全恢复丙酯草醚对高粱茎的生长抑制作用,而添加相同浓度的单一支链氨基酸只能部分消除其抑制作用.离体条件下,丙酯草醚IC50＞100mg/L,而双草醚IC50值为10-5～10-4mg/L,说明丙酯草醚对离体ALS没有抑制作用;活体条件下,丙酯草醚对ALS有一定的抑制作用,且随着处理时间的延长,酶活力降低,对ALS的抑制作用增加.因此,丙酯草醚使植物体内必需的支链氨基酸合成受阻,仍然属于ALS抑制剂,但其作用方式不同于磺酰脲类和嘧啶水杨酸类除草剂等典型的ALS抑制剂,它类似于前体农药,即在植物体内通过代谢活化来发挥作用. 相似文献
2.
八重樱不同器官除草活性研究 总被引：1，自引：0，他引：1
为了明确八重樱不同器官的除草活性,为进一步开展活性化合物的研究提供依据,以生菜、黄瓜、反枝苋、苘麻、小麦和稗草为受体植物,采用琼脂混粉法进行了室内活性测定。结果表明,八重樱的不同器官粉末在10 g/L的添加浓度下对各受体植物幼苗的生长均具有不同程度的抑制作用,且普遍对胚根(或种子根)生长的抑制效果高于对胚轴(或胚芽鞘)生长的抑制。其中,以根、叶和花器官表现出的抑制活性最强,而茎的抑制效果则相对较弱。6种受体植物幼苗的胚根对八重樱各器官所表现出的敏感性以生菜、反枝苋最高,黄瓜和苘麻次之,小麦及稗草相对较低。而它们的胚轴所表现出的敏感性以生菜和苘麻最高,小麦、黄瓜和反枝苋次之,稗草最低。说明八重樱各器官,特别是果实、叶和花中均含有高除草活性物质。 相似文献
3.
用乙酰乳酸合成酶(ALS)活性测定方法研究了双草醚、KIH-15127、苄嘧磺隆3种ALS抑制剂对水稻、稗草和油菜ALS活性的抑制差异性。体外测定结果表明，不同植物ALS对双草醚和KIH-15127的敏感性差异较大，粳稻、稗草和油菜ALS的敏感性强于籼稻，而这些植物ALS对苄嘧磺隆的敏感性差异很小。体内结果显示，双草醚和KIH-15127对稗草和油菜ALS的抑制作用较强，对粳稻ALS的抑制作用可以恢复；苄嘧磺隆对油菜ALS的抑制作用也较强，但对稗草、水稻ALS基本无抑制作用；3种ALS抑制剂对籼稻ALS抑制作用均较弱。结果表明，不同植物对ALS抑制剂的敏感性存在差异。 相似文献
4.
［目的］ 明确牡丹不同器官的除草活性,为进一步开展活性化合物的研究提供依据。［方法］ 以生菜、黄瓜、反枝苋、苘麻、小麦和稗为受试植物,采用琼脂混粉法进行室内活性测定。［结果］ 除茎器官外,牡丹其他各器官的粉末在10 g/L的添加浓度下,对各受体植物幼苗的生长均具有明显的抑制作用,且对胚根（或种子根）的抑制效果明显高于对胚轴（或胚芽鞘）的抑制。各器官中以根和叶的效果最好,花、果实和叶柄次之,茎最低。6种受体植物中,反枝苋幼苗的敏感性最高,而黄瓜最低。［结论］ 牡丹的不同器官粉末在10 g/L的添加浓度下对各受体植物幼苗的生长均具有不同程度的抑制作用。 相似文献
5.
为明确唑嘧磺草胺、丙炔氟草胺与乙草胺混用的联合作用特性及其对大豆田杂草的防除效果,采用温室盆栽法和田间药效试验,分别评价了混配组方的联合作用类型及对大豆田杂草的防除效果。温室盆栽试验结果表明:唑嘧磺草胺、丙炔氟草胺与乙草胺混用对稗草、马唐和苘麻的联合作用类型为相加作用,对反枝苋为相加或增效作用;当唑嘧磺草胺、丙炔氟草胺和乙草胺以质量比2 : 3 : 45混用时,对反枝苋的增效作用最强。田间药效试验结果显示:唑嘧磺草胺、丙炔氟草胺和乙草胺以质量比2 : 3 : 45混用,当用量为有效成分800和1 000 g/hm2时,可有效控制大豆田中杂草的为害,且对大豆安全。 相似文献
6.
石蝉草乙醇提取物除草活性初探 总被引：2，自引：0，他引：2
为探明石蝉草是否具有除草活性,本研究采用小杯法和盆栽试验法测定石蝉草乙醇提取物对13种植物的除草活性。结果表明,石蝉草乙醇提取物对13种植物的根茎生长均有抑制作用,对苘麻和稗草根长的抑制中浓度IC50分别为0.73和0.80mg/mL,对茎长的IC50分别为0.77和0.89mg/mL;盆栽试验表明,5mg/mL浓度对稗草和苘麻7d的防治效果分别为90.73%和82.02%,与对照药剂癸酸无显著性差异。研究结果为研发新型除草剂提供了新思路。 相似文献
7.
新化合物唑嘧氯草胺(ZJ-2725)除草活性评价 总被引：2，自引：2，他引：0
为明确新化合物唑嘧氯草胺的开发应用价值,采用室内生测法评价了新型三唑并嘧啶硫代乙酰胺类化合物唑嘧氯草胺(ZJ-2725)的除草活性、杀草谱及对作物的安全性.结果表明,唑嘧氯草胺对反枝苋等阔叶植物根的IC50为0.6994～10.3130 mg/L;而对禾本科杂草稗草和野燕麦根的IC50分别为20.3234mg/L和32.2657mg/L.唑嘧氯草胺茎叶处理对反枝苋、田旋花等的IC50为33.8708～40.7437 g/h㎡(有效成分,余同),对稗草和香附子等的IC50值为139.4231～277.6613 g/h㎡.与茎叶处理相比,土壤处理的除草效果较低.该化合物对小麦、玉米比较安全,其选择性系数分别为4.876、3.702,对白菜、油菜等双子叶作物敏感. 相似文献
8.
9.
为了明确荆条不同器官的除草活性,为进一步开展活性化合物的研究提供依据,采用琼脂混粉法于室内测定荆条对生菜、黄瓜、反枝苋、苘麻、小麦和稗草6种受体植物的除草活性。结果表明,在10 mg/mL的供试浓度下荆条不同器官粉末对6种植物幼苗均有明显的抑制作用,其中以花活性最高。进一步测定了花乙醇提取物及不同溶剂极性萃取物对6种植物幼苗生长的抑制作用,石油醚层和乙酸乙酯层的抑制活性较高,其中石油醚层对黄瓜幼根和乙酸乙酯层对稗草幼根的EC50分别为0.07、0.03 mg/mL,说明花含有较高的除草活性物质。 相似文献
10.
双草醚是组合化学公司开发的嘧啶水杨酸类除草剂,是高活性的乙酰乳酸合成酶（ALS）抑制剂,通过抑制植株所必需的支链氨基酸的生物合成来阻止细胞分裂,从而使植株停止生长,最终死亡。双草醚可有效防除稻田中的稗草及其他禾本科杂草,兼治大多数阔叶杂草、一些莎草科杂草,对二氯喹啉酸产生抗性的稗草亦有较好的防效。 相似文献
11.
Stephen O. Duke Antonio EvidenteMichele Fiore Agnes M. RimandoFranck E. Dayan Maurizio VurroNicole Christiansen Ralf LooserJohannes Hutzler Klaus Grossmann 《Pesticide biochemistry and physiology》2011,100(1):41-50
Ascaulitoxin and its aglycone (2,4,7-triamino-5-hydroxyoctanoic acid, CAS 212268-55-8) are potent phytotoxins produced by Ascochyta caulina, a plant pathogen being developed for biocontrol of weeds. The mode of action of this non-protein amino acid was studied on Lemna paucicostata. Ascaulitoxin is a potent growth inhibitor, with an I50 for growth of less than 1 μM, almost completely inhibiting growth at about 3 μM. Its action is slow, starting with growth inhibition, followed by darker green fronds, and then chlorosis and death. Most amino acids, including non-toxic non-protein amino acids, reversed the effect of the toxin when supplemented in the same medium. Supplemental sucrose slightly increased the activity. d-Amino acids were equally good inhibitors of ascaulitoxin activity, indicating the amino acid effects may not be due to inhibition of amino acid synthesis. Oxaloacetate, the immediate precursor of aspartate, also reversed the activity. LC-MS did not detect interaction of the compound with lysine, an amino acid that strongly reversed the effect of the phytotoxin. Metabolite profiling revealed that the toxin caused distinct changes in amino acids. Reduction in alanine, paralleled by enhanced levels of the branched chain amino acids valine, leucine and isoleucine and nearly unchanged levels of pyruvate, might indicate that the conversion of pyruvate to alanine is affected by ascaulitoxin aglycone. In addition, reduced levels of glutamate/glutamine and aspartate/asparagine might suggest that synthesis and interconversion reactions of these amino group donors are affected. However, neither alanine aminotransferase nor alanine: glyoxylate aminotransferase were inhibited by the toxin in vitro. Our observations might be explained by three hypotheses: (1) the toxin inhibits one or more aminotransferases not examined, (2) ascaulitoxin aglycone affects amino acid transporters, (3) ascaulitoxin aglycone is a protoxin that is converted in vivo to an aminotransferase inhibitor. 相似文献
12.
Christopher Preston Lynley M. Stone Mary A. Rieger Jeanine Baker 《Pesticide biochemistry and physiology》2006,84(3):227-235
Two populations of Lactuca serriola L. with resistance to acetolactate synthase (ALS)-inhibiting herbicides were discovered in wheat fields at two locations more than 25 km apart in South Australia. Both resistant populations carried a single base change within a highly conserved coding region of the ALS gene that coded for a single amino acid modification within ALS. The modification of proline 197 to threonine resulted in an enzyme that was highly resistant (>200-fold) to inhibition by sulfonylurea herbicides and moderately resistant to triazolopyrimidine and imidazolinone herbicides. The herbicide-resistant ALS was also less sensitive to inhibition by the branched-chain amino acids valine and leucine. In addition, the resistant enzyme had a lower Km for pyruvate. However, extractable ALS activity was similar between resistant and susceptible plants. The substitution of threonine for proline 197 within ALS has multiple impacts on ALS enzyme activity in L. serriola that may influence the frequency of this resistant allele in the environment. 相似文献
13.
Yasushi Tanaka 《Pesticide biochemistry and physiology》2003,77(3):147-153
Properties of acetolactate synthase (EC 4.1.3.18; ALS) from sulfonylurea-resistant (SUR) Scirpus juncoides Roxb. var. ohwianus T. Koyama were studied biochemically and physiologically in comparison with those from sulfonylurea-susceptible weed (SUS). GR50 values for growth inhibition and I50 values for ALS inhibition by imazosulfuron were determined for both SUR and SUS. Imazosulfuron controlled the SUS above 80% at the dosage more than 10 g a.i./ha but did not control the SUR at the even great dosage of 1000 g a.i./ha. The rates required for 50% growth inhibition of the SUR relative to the SUS (R/S ratio) were 271-fold. The I50 value for inhibition of ALS from the SUS was 15 nM, compared to I50 of >3000 nM for inhibition of ALS from the SUR. These results suggest that a resistance may due to an altered ALS that is insensitive to imazosulfuron. The Km (pyruvate) value of ALS from the SUR was similar to the Km for ALS from the SUS, suggesting that a mutation resulting in resistance does not change the affinity of the enzyme for pyruvate. The specific activity of the SUR ALS was similar to that of the SUS ALS, which indicates that resistance is not an over-expression of the enzyme. ALS activity from both biotypes was inhibited by isoleucine, valine, and leucine in this order. However, the SUR ALS was less sensitive to inhibition by valine than the SUS ALS. 相似文献
14.
《Pesticide biochemistry and physiology》2003,75(1-2):39-46
Responses of acetolactate synthase (ALS) from grass and broadleaf weed to sulfonylurea (SU) herbicide were compared in relation to the leaf position in a seedling and seedling age. The responses of Echinochloa crus-galli (L.) P. Beauv. and Eclipta prostrata L., dominant grass and broadleaf weed in paddy fields in Korea, respectively, to azimsulfuron were examined. In this study, in vivo ALS assay was used to verify the responsibility of selected weed species at different leaf stages to SU-herbicides. The data from in vivo ALS assay could be used for discriminating the degree of tolerance between weeds showed different susceptibility. In E. crus-galli and E. prostrata there was no apparent relationship between the chlorophyll concentrations and herbicide concentrations treated on leaves. Both in E. crus-galli and E. prostrata, the free amino acid concentrations, however, were increased as herbicide concentration increased in the younger leaves. The free amino acid concentrations were generally higher in older leaves than young leaves and were significantly increased concomitantly with increasing herbicide concentration. The ALS activity was decreased rapidly with higher azimsulfuron rates in old but not senescent leaves compared to juvenile leaves. Generally, ALS activity was less sensitive at the early leaf stage than late leaf stage. The activity of ALS in E. prostrata was highly responsive to application time and more susceptible to the herbicide as compared to E. crus-galli. The highest levels of acetoin were observed in the uppermost and youngest leaf in all species tested. 相似文献
15.
Ten accessions of sulfonylurea‐resistant Schoenoplectus juncoides were collected from paddy fields in Japan. In order to characterize acetolactate synthase from sulfonylurea‐resistant S. juncoides, acetolactate synthase amino acid substitutions, whole‐plant growth inhibition and acetolactate synthase enzyme inhibition were examined. Schoenoplectus juncoides has two acetolactate synthase genes (ALS1 and ALS2). The sulfonylurea‐resistant accessions harbored amino acid substitutions at Pro197 or Trp574 in either ALS1 or ALS2 (the amino acid number is standardized to the Arabidopsis thaliana sequence). The whole plants of all the sulfonylurea‐resistant accessions showed resistance to imazosulfuron. The resistance level depended on the altered amino acid residues in acetolactate synthase. The acetolactate synthase enzyme that was partially purified from all the sulfonylurea‐resistant accessions was less sensitive to imazosulfuron, compared to the susceptible accession, suggesting that the resistance is related to the altered acetolactate synthase enzyme. In addition, the concentration–response inhibition of acetolactate synthase activity by imazosulfuron in the sulfonylurea‐resistant accessions was remarkably different with the presence of an amino acid substitution in either ALS1 or ALS2. Furthermore, the concentration–response inhibition of acetolactate synthase activity in the sulfonylurea‐resistant accessions with a P197S, P197T or W574L mutation showed a double‐sigmoid curve. The regression analysis of enzyme inhibition suggested that the abundance ratio of ALS1 to ALS2 enzymes was approximately 70:30%, with a range of ±15%. Taken together, these results suggest that the resistance of sulfonylurea‐resistant accessions of S. juncoides is related to altered acetolactate synthase in either ALS1 or ALS2, although the abundance of the altered acetolactate synthase in the plants is different among the sulfonylurea‐resistant accessions. 相似文献
16.
A bird's eye review was tried in Part 2 of this series, 'Phytotoxic sites of action for molecular design of modern herbicides', in order to select the best selection of known and some novel plant-specific targets for molecular design of modern herbicides, which affect amino acid, lipid and cell wall biosynthesis. Although amino acid biosynthesis pathways, particularly those for aromatic amino acids, ammonia assimilation and branched amino acids, have been confirmed as reasonable herbicidal target domains, the other targets affecting plant growth more markedly than inhibition of 5-enolpyruvylshikimate-3-phosphate synthase, glutamine synthetase and acetolactate synthase are discussed. In three essential enzymes involved in fatty acid biosynthesis in or in the vicinity of chloroplasts, acetyl-CoA carboxylase (ACCase), elongase(s) for very long chain fatty acids (VLCFA) and linolate monogalactosyldiacylglycerol desaturase, ACCase and elongase are more important targets for new herbicides. Although the effect of cellulose biosynthesis inhibitors is restricted to cell wall formation in growing plant cells only, there is a good chance to design the low-use rate herbicides also in this class of inhibitors. Other possible targets for new herbicides are also discussed. 相似文献
17.
Luis Orcaray María Igal Daniel Marino Ana Zabalza Mercedes Royuela 《Pest management science》2010,66(3):262-269
BACKGROUND: The herbicide glyphosate inhibits the biosynthesis of aromatic amino acids by blocking the shikimate pathway. Imazethapyr and chlorsulfuron are two herbicides that act by inhibiting branched‐chain amino acid biosynthesis. These herbicides stimulate secondary metabolism derived from the aromatic amino acids. The aim of this study was to test if they cause any cross‐effect in the amino acid content and if they have similar effects on the shikimate pathway. RESULTS: The herbicides inhibiting two different amino acid biosynthesis pathways showed a common pattern in general content of free amino acids. There was a general increase in total free amino acid content, with a transient decrease in the proportion of amino acids whose pathways were specifically inhibited. Afterwards, an increase in these inhibited amino acids was detected; this was probably related to proteolysis. All herbicides caused quinate accumulation. Exogenous application of quinate arrested growth, decreased net photosynthesis and stomatal conductance and was ultimately lethal, similarly to glyphosate and imazethapyr. CONCLUSIONS: Quinate accumulation was a common effect of the two different classes of herbicide. Moreover, exogenous quinate application had phytotoxic effects, showing that this plant metabolite can trigger the toxic effects of the herbicides. This ability to mimic the herbicide effects suggests a possible link between the mode of action of these herbicides and the potential role of quinate as a natural herbicide. Copyright © 2009 Society of Chemical Industry 相似文献
18.
Heinrich Buchenauer 《Pesticide biochemistry and physiology》1977,7(4):309-320
Triadimefon [1-(4-chlorophenoxy)-3,3-dimethyl-(1,2,4-triazol-1-yl)-2-butanone], 1.5–2.0 μ/ml, inhibited the multiplication of sporidia of Ustilago avenae more strongly than it did the increase of dry weight. The treated sporidia appeared swollen, multicellular, and branched. At concentrations of 1.5–100 μg of triadimefon/ml, the oxidation of glucose was not affected. Increase in dry weight and synthesis of protein, RNA, and DNA were inhibited slightly, whereas cell division was acutely arrested. After an incubation period of 9.5 hr, microscopic studies revealed that daughter cells of the treated sporidia also contained one nucleus. In sporidia treated for 6 hr with triadimefon, both the total lipid content and its composition of fatty acids were not appreciably altered. The treated cells, however, differed from control cells by a higher content of free fatty acids. Triadimefon markedly interfered in sterol biosynthesis in Ustilago avenae. Gas chromatographic (glc) analysis and [14C]acetate incorporation studies indicated that ergosterol biosynthesis was almost completely inhibited by triadimefon; on the other hand, sterol compounds representing precursors of ergosterol (probably 4,4-dimethyl and C-4-methyl sterols) accumulated in treated sporidia. As the results indicate, the inhibition of conversion of immediate sterol precursors to ergosterol may be regarded as the primary target for the action of triadimefon in Ustilago avenae. 相似文献
19.
Heinrich Buchenauer 《Pesticide biochemistry and physiology》1978,8(1):15-25
Fluotrimazole [BUE 0620; 1-(3-trifluoromethyltriphenyl) 1,2,4-triazole] (20 μg/ml of nutrient solution) and clotrimazole [Bay b 5097; bisphenyl(2-chlorophenyl)-1-imidazolyl methane] (5 μg/ml) did not inhibit dry weight increase and only slightly reduced multiplication of sporidia of Ustilago avenae during the first doubling period (about 4 hr). After 8 hr, both fluotrimazole and clotrimazole more strongly inhibited sporidia multiplication than dry weight increase. As a consequence of treatment with both fungicides the usually single-celled sporidia appear swollen, multicellular, and branched. Both chemicals at a concentration range of 5–100 μg/ml did not affect oxidation of glucose. The effect of fluotrimazole and clotrimazole on protein, DNA, and RNA synthesis was similar to that on dry weight. Following a 6-hr incubation period total lipid synthesis was quantitatively unaffected by both chemicals. As the analysis of major fatty acids of total lipids revealed fluotrimazole substantially induced the synthesis of 20:4 carbon fatty acids, while in clotrimazole-treated sporidia the pattern of fatty acids did not differ from that of control sporidia. Fluotrimazole and clotrimazole produced a higher quantity of free fatty acids in sporidia of U. avenae. Gas-liquid chromatographic analysis of sterol fractions in treated and control sporidia (6 hr) indicated that both fluotrimazole and clotrimazole seriously inhibited ergosterol biosynthesis and concomitantly caused an accumulation of immediate ergosterol precursors which represent C-4-methyl and 4,4-dimethyl sterols. Incorporation of [14C]acetate for 2 hr into various lipid fractions of sporidia of U. avenae also revealed that radioactivity in C-4-desmethyl sterols in both fluotrimazole- and clotrimazole-treated sporidia was drastically reduced, while the radioactivity of C-4-methyl and 4,4-dimethyl sterols distinctly increased. The data suggest that fluotrimazole and clotrimazole are specific inhibitors of the oxidative demethylation of the C-14-methyl group during ergosterol biosynthesis in U. avenae. 相似文献