乙酰辅酶A羧化酶抑制剂的研究进展

乙酰辅酶A羧化酶(ACCase)是除草剂的作用靶标之一，此类除草剂主要有两类：芳氧苯氧丙酸类(APP)和环己烯酮类(环己二酮，环己烯二酮，CHD)。本文就ACCase抑制剂的发展历史、合成方法、结构与活性和除草机制等方面作了概述。     

天然产物除草剂研究进展

本文综述了天然产物除草剂即生物源除草剂的基本概念、特点、分类和研究进展,概括了天然产物除草剂面临的问题及发展方向。主要介绍了植物源除草剂和微生物源除草剂的研究概况,为应用天然产物进行杂草防除提供理论依据,促进天然产物除草剂的研究。     

几种酰胺类选择性除草剂的特性

自盂山都公司于1956年开发成功旱田除草剂二丙烯草胺后,酰胺类除草剂有较大发展,到目前已有53个品种商品化,其中氯代乙酰胺类占主导地位。目前得到市场广泛认同的氯代乙酰胺类除草剂主要包括甲草胺、乙草胺、丙草胺、丁草胺、异丙草胺、异丙甲草胺、精异丙甲草胺等7种,它们是高效、高选择性除草剂,大多数用于防除一年生禾本科杂草。     

杂草对乙酰乳酸合成酶抑制剂抗药性研究进展

乙酰乳酸合成酶(ALS)抑制剂类除草剂已经成为一类广泛使用的除草剂。综述了杂草对ALS抑制剂类除草剂抗药性的产生与发展、抗性机理、抗性基因应用等方面的研究进展。其抗性产生机理主要有杂草对除草剂代谢能力增强、ALS基因突变导致对除草剂敏感性降低和ALS含量提高等。     

氨基酸类(草甘膦)除草剂品种的市场发展前景

氨基酸类除草剂主要有草甘膦、草铵膦、双丙氨膦及草硫膦4个品种。由于它们都含有膦酸结构,也有将它们归为有机磷类除草剂的结构类别。生1996年以来,由于抗除草剂转基因作物的崛起,此类除草剂得以飞速发展,成为18类除草剂中甚至所有农药类别之首。     

原卟啉原氧化酶抑制剂的结构演变

原卟啉原氧化酶抑制剂类除草剂是近年来发展最快的除草剂品系之一。这类除草剂引起植物的典型生理变化主要有生长抑制、叶绿素降解、原卟啉IX积累、膜降解产生短链碳氢化合物。其基本特征是活性氧导致过氧化作用，因此又可称为过氧化除草剂（peroxidizing herbicide）。由于此类除草剂以叶绿素为作用点．确保了动植物之间的选择毒性，具有超高效、低毒的特点，成为新型除草剂的热点。早期的二苯醚类除草剂是这类除草剂的代表，     

吡啶甲酸类除草剂应用研究进展

吡啶甲酸类除草剂属合成激素类, 目前登记使用的有效成分包括氨氯吡啶酸、二氯吡啶酸和氯氨吡啶酸, 分别于1963年、1977年和2005年上市, 主要用于阔叶杂草和灌木的茎叶处理防控, 其中氯氨吡啶酸具有土壤封闭活性。吡啶甲酸类除草剂的作用靶标仍未明确, 有可能来自生长素结合蛋白家族。全世界报道的抗吡啶甲酸类除草剂杂草共涉及7种8个生物型。目前, 我国登记的除草剂品种中共有13个复配剂含氨氯吡啶酸和二氯吡啶酸, 1个含氨氯吡啶酸、氯氨吡啶酸和二氯吡啶酸;国外登记的吡啶甲酸类除草剂复配剂主要为与其他激素型除草剂、ALS(乙酰乳酸合酶)抑制剂、ACCase(乙酰辅酶A羧化酶)抑制剂的组合。该类除草剂仍然具有较好的应用前景, 在主要应用场景下常见杂草对氨氯吡啶酸、二氯吡啶酸、氯氨吡啶酸的敏感性仍需系统研究, 该类除草剂主要靶标杂草种群的抗药性水平也亟须检测。     

超高效除草剂磺酰脲类述评

磺酰脲类化合物是一类超高效除草剂,其生物活性之高、单位面积用药量之低在除草剂品种发展中是空前的。此类除草剂的发现是除草剂开发与化学除草技术发展的重大突破,它将给杂草防治带来深刻的变革。此类除草剂于1975年发现,1977与1979年其中的一些化合物取得专利;1978年LevittG.与1979年Finnerty D.W.报道了N-(1,3,5-三氮苯基氨基羰基)苯磺酰胺的活性,随之     

抗除草剂转基因水稻的研究进展

水稻是我国乃至世界上最重要的粮食作物之一,杂草是影响水稻产量和品质的主要因素。近年来,抗除草剂转基因水稻的研究与应用取得了较大进展。本文概述了稻田的主要杂草及防除方法,简述了稻田常用的几种除草剂及其作用机理,介绍了全球抗除草剂转基因作物的现状,着重阐述了抗除草剂转基因水稻的研发进展、应用及未来发展方向。     

农得时,草克星,莎多伏除草活性及活性机理研究进展

农得时、草克星、莎多伏除草活性及活性机理研究进展陈杰，李扬汉（南京农业大学杂草研究室２１００９５）磺酰脲类除草剂是７０年代中期由杜邦公司Ｇｅｏｒｇｅｌｅｖｉｔｔ博士发现的，目前已成为一类主要的除草剂，是现代农业化学发展史上的一大突破。至１９９３年已商...     

Biochemical mechanisms of cross-resistance to aryloxyphenoxypropionate and cyclohexanedione herbicides in populations of Avena spp.

Aryloxyphenoxypropionate (APP) and cyclohexanedione (CHD) herbicides are used extensively in the UK to control grass weeds, including Avena spp. (wild-oats). Reports of resistance to APP and CHD herbicides are a particular concern for the agricultural community. In this study, the responses of four UK Avena populations were characterized towards the APP herbicides fenoxaprop-P-ethyl and fluazifop-P-butyl, and towards the CHD herbicides cycloxydim and tralkoxydim. An A. sterilis ssp. ludoviciana population (T/41) was found to be highly resistant to fenoxaprop-P-ethyl and fluazifop-P-butyl, but did not show cross-resistance to cycloxydim and tralkoxydim. In contrast, one A. sterilis ssp. ludoviciana (T/11) and one A. fatua population (Dorset) showed partial resistance to both APP herbicides and also showed cross-resistance to the CHD herbicide tralkoxydim, but not to cycloxydim. Before this study, the biochemical mechanisms that confer resistance to the APP and CHD herbicides in UK Avena populations were unknown. Results from the present study show that an enhanced rate of metabolism of fenoxaprop-P-ethyl was found to confer resistance in the two partially resistant Avena populations (T/11 and Dorset), and the presence of an insensitive form of the target enzyme, ACCase, was responsible for target site resistance to fenoxaprop-P-ethyl and fluazifop-P-butyl in the highly resistant population T/41. Cross-resistance to the CHD herbicide tralkoxydim in the T/11 and Dorset populations was not conferred by insensitive ACCase, and was most probably caused by enhanced metabolism. This is the first report that resistance to fenoxaprop-P-ethyl can be conferred by enhanced metabolism in Avena spp.     

稻田除草剂选择智能决策系统APP的构建与思考

当前我国水稻田登记的除草剂活性成分组合共204种,包括55种单剂和149种复配剂.在总结各种稻田除草剂应用技术要素的基础上,提出稻田除草剂选用中具有普遍性的6个关键问题,包括:水稻栽培方式、稻田除草剂施用时期、施用方法、稻田主要禾本科杂草种类、稻田非禾本科主要杂草类型、田间杂草生育期;基于各种除草剂品种对应上述6个问题...     

杂草对芳氧苯氧丙酸类(APPs)除草剂的抗性分子机理研究进展

芳氧苯氧丙酸类（aryloxyphenoxypropionates,APPs）除草剂是一类广泛使用的乙酰辅酶A羧化酶抑制剂,可高效专一抑制禾本科杂草的乙酰辅酶A羧化酶（acetyl-coenzyme A carboxylase,ACCase）。目前已出现大量抗芳氧苯氧丙酸类除草剂的禾本科杂草,其抗性大多由叶绿体乙酰辅酶A羧化酶的羧基转移酶（carboxyltransferase,CT）功能域中的氨基酸突变引起。在所有已发现的氨基酸突变中,最引人关注的是第1 781位（对应大穗看麦娘Alopecurus myosuroides质体ACCase的氨基酸残基位置）异亮氨酸到亮氨酸的单点突变,该特定位置形成亮氨酸会导致某些杂草对APPs类除草剂产生抗性。综述了乙酰辅酶A羧化酶CT功能域的研究进展及杂草对APPs类除草剂的抗性分子机理,探讨了杂草对APPs类除草剂抗性分子机理研究中存在的问题,以期为进一步深入研究APPs类除草剂的抗性机制提供参考。     

First report of target-site resistance to ACCase-inhibiting herbicides in Bromus tectorum L.

Background

The prevalent and repeated use of acetyl-coenzyme A carboxylase (ACCase)-inhibiting herbicides for Bromus tectorum L. control in fine fescue (Festuca L. spp) grown for seed has selected ACCase-resistant B. tectorum populations. The objectives of this study were to (1) evaluate the response of nine B. tectorum populations to the ACCase inhibitors clethodim, sethoxydim, fluazifop-P-butyl, and quizalofop-P-ethyl and the acetolactate synthase (ALS) inhibitor sulfosulfuron and (2) characterize the resistance mechanisms.

Results

Bromus tectorum populations were confirmed to be resistant to the ACCase-inhibiting herbicides tested. The levels of resistance varied among the populations for clethodim (resistance ratio, RR = 5.1–14.5), sethoxydim (RR = 18.7–44.7), fluazifop-P-butyl (RR = 3.1–40.3), and quizalofop-P-ethyl (RR = 14.5–36). Molecular investigations revealed that the mutations Ile2041Thr and Gly2096Ala were the molecular basis of resistance to the ACCase-inhibiting herbicides. The Gly2096Ala mutation resulted in cross-resistance to the aryloxyphenoxypropionate (APP) herbicides fluazifop-P-butyl and quizalofop-P-ethyl, and the cyclohexanedione (CHD) herbicides clethodim, and sethoxydim, whereas Ile2041Thr mutation resulted in resistance only to the two APP herbicides. All B. tectorum populations were susceptible to sulfosulfuron (RR = 0.3–1.7).

Conclusions

This is the first report of target-site mutations conferring resistance to ACCase-inhibiting herbicides in B. tectorum. The results of this study suggest multiple evolutionary origins of resistance and contribute to understanding the patterns of cross-resistance to ACCase inhibitors associated with different mutations in B. tectorum. © 2023 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.     

Tolerance to acetolactate synthase and acetyl-coenzyme A carboxylase inhibiting herbicides in Vulpia bromoides is conferred by two co-existing resistance mechanisms

Vulpia bromoides is a grass species naturally tolerant to acetolactate synthase (ALS) and acetyl-coenzyme A carboxylase (ACCase) inhibiting herbicides. The mechanism of tolerance to ALS herbicides was determined as cytochrome P450-monooxygenase mediated metabolic detoxification. The ALS enzyme extract partially purified from V. bromoides shoot tissue was found to be as sensitive as that of herbicide susceptible Lolium rigidum to ALS-inhibiting sulfonylurea (SU), triazolopyrimidine (TP), and imidazolinone (IM) herbicides. Furthermore, phytotoxicity of the wheat-selective SU herbicide chlorsulfuron was significantly enhanced in vivo in the presence of the known P450 inhibitor malathion. In contract, the biochemical basis of tolerance to ACCase inhibiting herbicides was established as an insensitive ACCase. In vitro ACCase inhibition assays showed that, compared to a herbicide susceptible L. rigidum, the V. bromoides ACCase was moderately (4.5- to 9.5-fold) insensitive to the aryloxyphenoxypropionate (APP) herbicides diclofop, fluazifop, and haloxyfop and highly insensitive (20- to >71-fold) to the cyclohexanedione (CHD) herbicides sethoxydim and tralkoxydim. No differential absorption or de-esterification of fluazifop-P-butyl was observed between the two species at 48 h after herbicide application, and furthermore V. bromoides did not detoxify fluazifop acid as rapidly as susceptible L. rigidum. It is concluded that two co-existing resistance mechanisms, i.e., an enhanced metabolism of ALS herbicides and an insensitive target ACCase, endow natural tolerance to ALS and ACCase inhibiting herbicides in V. bromoides.     

Mechanism of resistance to fenoxaprop in Japanese foxtail (Alopecurus japonicus) from China

Japanese foxtail is one of the most common and troublesome weeds infesting cereal and oilseed rape fields in China. Repeated use during the last three decades of the ACCase-inhibiting herbicide fenoxaprop-P-ethyl to control this weed has resulted in the occurrence of resistance. Dose–response tests established that a population (AHFD-1) from eastern China had evolved high-level resistance to fenoxaprop-P-ethyl. Based on the resistance index, this resistant population of A. japonicus is 60.31-fold resistant to fenoxaprop-P-ethyl. Subsequently, only a tryptophan to cysteine substitution was identified to confer resistance to fenoxaprop-P-ethyl in this resistant population. ACCase activity tests further confirmed this substitution was linked to resistance. This is the first report of the occurrence of Trp-2027-Cys substitution of ACCase in A. japonicus. From whole-plant pot dose–response tests, we confirmed that this population conferred resistance to other APP herbicides, including clodinafop-propargyl, fluazifop-P-butyl, quizalofop-P-ethyl, haloxyfop-R-methyl, cyhalofop-butyl, metamifop, DEN herbicide pinoxaden, but not to CHD herbicides clethodim, sethoxydim. There was also no resistance observed to ALS-inhibiting herbicides sulfosulfuron, mesosulfuron-methyl, flucarbazone-sodium, pyroxsulam, Triazine herbicide prometryne and glyphosate. However, this resistant population was likely to confer slightly (or no) resistant to Urea herbicides chlortoluron and isoproturon.     

A pollen test to detect ACCase target‐site resistance within Alopecurus myosuroides populations

This study was conducted to determine a suitable medium for in vitro germination of Alopecurus myosuroides pollen and to develop a reliable test for the rapid screening of ACCase target site‐resistant plants within populations. The assay is based upon germination of pollen in a medium supplemented with ACCase inhibitors. A 0.25% agar medium, containing 200 mg L^–1 CaNO₃, 100 mg L^–1 H₃BO₃, 200 g L^–1 sucrose, was selected as a suitable medium for in vitro pollen germination. At 25 °C, this medium supported a mean germination rate of 85% within two hours. Plants highly resistant (Rh) to aryloxyphenoxypropionate (APP), owing to the expression of an insensitive ACCase, were found to express this resistance in their pollen. In contrast, plants moderately resistant (Rm) to APP herbicides, owing to an enhanced capacity to detoxify herbicides, did not exhibit this resistance in their pollen. Concentrations of 120 μM fenoxaprop and 1000 μM clodinafop were selected as the best for reliable discrimination of the target‐site‐resistant biotypes. At these concentrations there was more than 50% germination of the Rh pollen grains whereas less than 10% of the S and Rm pollen grains germinated. This test, using haploid material, may also permit distinction between homozygous‐ and heterozygous‐resistant individuals.     

A rapid reliable test for screening aryloxyphenoxy- propionic acid resistance within Alopecurus myosuroides and Lolium spp. populations

A reliable seedling bioassay was developed and tested for the rapid screening for resistance to aryloxyphenoxypropionic (APP) herbicides in Alopecurus myosuroides and Lolium spp. populations. It is based upon the difference in coleoptile length of resistant and susceptible A. myosuroides and Lolium seedlings, respectively, exposed to fenoxaprop-P acid and diclofop acid solution for 6 days in a plastic box. A 6 mg L⁻¹ fenoxaprop-P acid solution was selected as the best concentration for a reliable screening of resistant biotypes within A. myosuroides populations. At this concentration, coleoptile lengths of susceptible and resistant seedlings were shorter and longer than 10 mm respectively. Similarly, resistant seedlings within Lolium populations were easily detected at 10 mg L⁻¹ diclofop acid. At this concentration, coleoptile lengths of susceptible and resistant seedlings were shorter and longer than 20 mm respectively. For both populations, the coleoptile length distributions appear to discriminate between two kinds of APP-resistant biotypes (highly and slightly resistant).     

A Diclofop-methyl-Resistant Avena sterilis Biotype with a Herbicide-Resistant Acetyl-coenzyme A Carboxylase and Enhanced Metabolism of Diclofop-methyl

An Avena sterilis biotype was found to be highly resistant to aryloxyphenoxypropionate (APP) herbicides, especially diclofop-methyl. At the enzyme level, this biotype contained a modified acetyl-coenzyme A carboxylase (ACCase) with six-fold resistance to diclofop acid. Absorption and translocation of [¹⁴C]diclofop-methyl applied to the leaf axil of the two-leaf stage plants were similar in both susceptible and resistant biotypes. However, the rate of metabolism of [¹⁴C]diclofop was increased 1·5-fold in this resistant biotype compared to the susceptible. Experiments with tetcyclacis, a cytochrome P450 monooxygenase inhibitor, indicated that inhibition of this enhanced diclofop metabolism increased diclofop-methyl phytotoxicity in this biotype. Studies with ten individual families of the resistant biotype indicated that both mechanisms of resistance, an altered target site and enhanced metabolism, are present in each individual of the population. Hence, it is likely that these two mechanisms of resistance both contribute to resistance in this biotype. © 1997 SCI.