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。     

国内外抗除草剂基因专利的分析

抗除草剂基因是培育抗除草剂转基因作物的基础。自1983年第1例抗草甘膦基因报道以来,到目前已经从微生物和植物中发掘出大量的抗性基因,并采用人工改造和基因融合的方法获得了新的抗性基因。本文归纳总结了国内外抗除草剂基因的专利,目的是为我国抗除草剂基因的发掘提供参考。经统计发现,国际上抗除草剂基因专利有52项,发掘的基因对草甘膦、草丁膦、磺酰脲类、溴苯腈、2,4-D、麦草畏、咪唑啉酮类、苯并呋喃类、吡啶甲酸酯类、原卟啉原氧化酶(PPO)抑制剂类、羟苯基丙酮酸加双氧酶(HPPD)抑制剂类、芳氧苯氧丙酸酯类(包括喹禾灵)和环己烯酮类13个种类除草剂有抗性。我国有48项专利,发掘的基因对草甘膦、草丁膦、咪唑啉酮类、磺酰脲类4个种类除草剂有抗性,且40项属于抗草甘膦基因。我国虽在专利数量上与国外相差不大,但在种类上远不及国外。因此,在我国抗除草剂基因的研究与开发方面面临着挑战。     

甜菜田除草剂应用研发进展

本文介绍了甜菜田经常使用的19个除草剂,包括芳氧苯氧羧酸类6个、环己二酮类2个、酰胺类3个、(硫代)氨基甲酸酯类4个、二硝基苯胺类2个、三嗪类1个、苯并呋喃甲磺酸酯类1个。提出了可以在甜菜田筛选的9个除草剂,包括磺酰脲类5个、磺酰胺类4个。简述了甜菜田除草剂的选用策略。     

(E)-O-芳酰基-α-氧代环十二酮肟的合成及除草活性

以环十二酮为原料 ,制得中间体 (E) -α-氧代环十二酮肟 (Ⅳ)后 ,经酰化合成了九个 (E) - O-芳酰基 -α-氧代环十二酮肟 (Ⅴ) ,它们的结构得到元素分析、IR和 1HNMR的确证。生测结果表明 ,部分化合物具有良好的除草活性。对活性较高的 3还通过精密毒力测定 ,求得 IC50 值。中间体 在贝克曼反应条件下发生断裂反应生成 11-氰基十一酸 (Ⅶ) ,证实了 具有 (E) -构型的结构特征。     

α-芳氧丙酸酯的合成及除草活性

以三乙胺为缚酸剂,通过α-芳氧丙酸与α-溴代嚬哪酮反应,合成了19个α-芳氧丙酸-2-氧代-3,3-二甲基丁醇酯类新化合物,其结构均经IR、1H NMR及元素分析确证。用小杯法初步测试了化合物的除草活性,结果表明,在施药剂量为0.225g/m2时,部分化合物具有较好的除草活性,其中化合物Ⅲp、Ⅲq和Ⅲr对苋菜Amaranthus retroflexus、油菜Brassica campestris和苜蓿Medicagosaliva生长的抑制率大多达到100%。     

乙酰辅酶A羧化酶抑制剂类除草剂与杂草的抗药性

乙酰辅酶A羧化酶(ACCase)是芳氧苯氧基丙酸类(AOPP)除草剂和环己烯酮类(CHD)除草剂的作用靶标酶，这类除草剂对禾本科杂草有优异的防除效果，属于超高效型除草剂，使用范围较广，但同时也发现连续使用该类除草剂，杂草容易产生抗药性。本文概述了AOPP和CHD类除草剂的现状、作用机理及抗该类除草剂杂草的分布、危害，并探讨了杂草对该类除草剂的抗性机理、抗性控制等。     

磺酰脲类除草剂的使用与杂草抗药性

1970年首次报道了杂草对均三氮苯类除草剂产生抗性,杂草对除草剂的抗性也随着除草剂的使用而不断发展与蔓延。到目前为止,已有100种以上杂草对不同类型除草剂产生了抗性,其中涉及均三氮苯、联吡啶、苯氧羧酸、苯基脲、二硝基苯胺、芳氧苯氧丙酸、环己烯酮、三唑、咪唑啉酮、磺酰脲等,从而使杂草抗性成为除草剂品种开发及化学除草中的重要问题。在杂草对众多类型除草剂产生抗性的事例中,杂草对超高效除草剂磺酰脲类化合物的抗性最引人注目。     

新型芳氧吡啶肟醚类化合物的设计、合成和杀虫活性

以芳氧吡啶乙酮分子插件为基础，设计合成了一系列芳氧吡啶乙酮肟醚类化合物，其结构经核磁共振氢谱、碳谱及高分辨质谱等确证。初步杀虫活性测定结果表明，该系列化合物对棉蚜 Aphis gossypii (Glover) 具有较好的杀虫活性，其中化合物 5a 和 6i 在50 μg/mL下对棉蚜的致死率分别为76.8%和70.1%，具有作为先导化合物进一步研究的价值；但其对小菜蛾的杀虫活性较差，在100 μg/mL下的致死率普遍低于30%。该系列化合物主要体现出了新烟碱类化合物的活性特征，为进一步研究其构效关系提供了新思路。     

新型取代氨基(或芳氧)磺酰基苯氧丙酸酯的合成及其除草活性

由α-苯氧基丙酸酯出发,合成了取代氨基(或芳氧)磺酰基苯氧丙酸酯,并测定了它们的除草活性。所有的化合物均经1H NMR和元素分析确证,初步的生测结果表明上述化合物具有一定的除草活性。     

乙酰辅酶A羧化酶抑制剂的构效关系和抗性研究进展

乙酰辅酶A羧化酶(ACCase)抑制剂是以乙酰辅酶A羧化酶为作用靶标的一类除草剂.这类除草剂通过抑制真核型乙酰辅酶A生成丙二酰辅酶A的羧化反应,进而抑制植物脂肪酸的合成,多用于苗后有选择性地防除一年生禾本科杂草.本文综述了该类除草剂的作用机理、构效关系及在应用中的抗性研究进展.     

Altered acetyl-coenzyme A carboxylase confers resistance to clethodim, fluazifop and sethoxydim in Setaria faberi and Digitaria sanguinalis

Summary Populations of Setaria faberi and Digitaria sanguinalis cross-resistant to sethoxydim and fluazifop-P-butyl were identified in a vegetable cropping system in Wisconsin, USA, in 1991 and 1992 respectively. Experiments were conducted with partially purified acetyl-CoA carboxylase (ACCase) to determine whether resistance to sethoxydim and other ACCase inhibitors in S. faberi and D. sanguinalis resulted from altered enzyme activity. Based on I₅₀ values (the herbicide dose that inhibited ACCase activity by 50% compared with untreated ACCase), ACCase of the resistant accession of S. faberi was 4.8-, 10.6- and 319-fold resistant to clethodim, fluazifop-P acid and sethoxydim, respectively, compared with that of the susceptible accession. Similarly, ACCase of the resistant accession of D. sanguinalis was 5.8-, 10.3- and 66-fold resistant to clethodim, fluazifop-P acid and sethoxydim respectively. These results indicated that resistance to ACCase inhibitors in these accessions of S. faberi and D. sanguinalis resulted from an altered ACCase enzyme that confers a very high level of resistance to sethoxydim.     

Allelic variation of the ACCase gene and response to ACCase-inhibiting herbicides in pinoxaden-resistant Lolium spp

BACKGROUND: The repeated use of acetyl‐coenzyme A carboxylase (ACCase) inhibiting herbicides to control grass weeds has selected for resistance in Lolium spp. populations in Italy. The efficacy of pinoxaden, a recently marketed phenylpyrazoline herbicide, is of concern where resistance to ACCase inhibitors has already been ascertained. ACCase mutations associated with pinoxaden resistance were investigated, and the cross‐resistance pattern to clodinafop, haloxyfop, sethoxydim, clethodim and pinoxaden was established on homo/heterozygous plants for four mutant ACCase alleles. RESULTS: Seven different mutant ACCase alleles (1781‐Leu, 1999‐Leu, 2041‐Asn, 2041‐Val, 2078‐Gly, 2088‐Arg and 2096‐Ala) and 13 combinations with two types of mutation were detected in the pinoxaden‐resistant plants. The 1781‐Leu allele appears to confer a dominant resistance to pinoxaden, clodinafop, haloxyfop, sethoxydim and clethodim at 60 g AI ha^?1. The 2041‐Asn and 2041‐Val alleles are associated with dominant or partially dominant resistance to FOPs, no substantial resistance to DIMs and a moderate resistance to pinoxaden. The 2088‐Arg allele endows a partially dominant resistance to clodinafop, sethoxydim and most likely to pinoxaden. In addition, non‐target‐site resistance mechanisms seem to be involved in pinoxaden resistance. CONCLUSION: Almost all the ACCase mutations selected in the field by other ACCase inhibitors are likely to confer resistance to pinoxaden. Although pinoxaden is sometimes able to control FOP‐resistant populations, it should not be considered as a sustainable ACCase resistance management tool. The presence of non‐ACCase‐based resistance mechanisms that could confer resistance to herbicides with different modes of action further complicates the resistance management strategies. Copyright © 2011 Society of Chemical Industry     

Cross-resistance patterns to ACCase-inhibiting herbicides conferred by mutant ACCase isoforms in Alopecurus myosuroides Huds. (black-grass), re-examined at the recommended herbicide field rate

BACKGROUND: Target‐site‐based resistance to acetyl‐CoA carboxylase (ACCase) inhibitors in Alopecurus myosuroides Huds. is essentially due to five substitutions (Isoleucine‐1781‐Leucine, Tryptophan‐2027‐Cysteine, Isoleucine‐2041‐Asparagine, Aspartate‐2078‐Glycine, Glycine‐2096‐Alanine). Recent studies suggested that cross‐resistance patterns associated with each mutation using a seed‐based bioassay may not accurately reflect field resistance. The authors aimed to connect the presence of mutant ACCase isoform(s) in A. myosuroides with resistance to five ACCase inhibitors (fenoxaprop, clodinafop, haloxyfop, cycloxydim, clethodim) sprayed at the recommended field rate. RESULTS: Results from spraying experiments and from seed‐based bioassays were consistent for all mutant isoforms except the most widespread, Leucine‐1781. In spraying experiments, Leucine‐1781 ACCase conferred resistance to clodinafop and haloxyfop. Some plants containing Leucine‐1781 or Alanine‐2096 ACCase, but not all, were also resistant to clethodim. CONCLUSION: Leucine‐1781, Cysteine‐2027, Asparagine‐2041 and Alanine‐2096 ACCases confer resistance to fenoxaprop, clodinafop and haloxyfop at field rates. Leucine‐1781 ACCase also confers resistance to cycloxydim at field rate. Glycine‐2078 ACCase confers resistance to all five herbicides at field rates. Only Glycine‐2078 ACCase confers clethodim resistance under optimal application conditions. It may be that Leucine‐1781 and Alanine‐2096 ACCases may also confer resistance to clethodim in the field if the conditions are not optimal for herbicide efficacy, or at reduced clethodim field rates. Copyright © 2008 Society of Chemical Industry     

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。     

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.     

Herbicide-resistant barnyardgrass (Echinochloa crus-galli) in global rice production

Barnyardgrass (Echinochloa crus-galli (L.) Beauv.), an annual species of the family Poaceae, is a major weed problem in rice-producing countries throughout the globe. Synthetic herbicides can effectively control this grass in rice paddies, but the development of resistant biotypes after the continuous use of the same active ingredients has led to low herbicide efficacy and yield losses. In this review, a summary of resistant-barnyardgrass cases in global rice production is reported based on data from the International Herbicide-Resistant Weed Database. The first case of resistant barnyardgrass in rice paddies was to the photosystem-II inhibitor propanil in the late 1980s. Eighty-five (85) out of 116 cases in the period from 1986 to 2022 refer to resistant barnyardgrass (E. crus-galli var. crus-galli, E. crus-galli var. formosensis and E. crus-galli var. zelayensis) in 16 countries. Barnyardgrass has been found resistant to acetolactate synthase (ALS) inhibitors (34 cases), acetyl-CoA carboxylase (ACCase) inhibitors (23 cases), photosystem-II inhibitors (11 cases), auxin mimics/cellulose biosynthesis inhibitors (9 cases), very long chain fatty acid inhibitors (6 cases), and microtubule assembly inhibitors (1 case). The majority of all resistance cases reported to the active ingredients penoxsulam, bispyribac-sodium, and imazamox (ALS inhibitors), cyhalofop-butyl and fenoxaprop-ethyl (ACCase inhibitors), propanil (photosystem-II inhibitors), and quinclorac (auxin mimics/cellulose biosynthesis inhibitors). Although target-site resistance with specific mutations has been identified, non-target site resistance mainly through herbicide detoxification is also of great concern increasing the chance of multiple herbicide resistance evolution. Rotation of herbicides should be adopted concerning the modes of action used as well as the application methods to mitigate resistance evolution of this weed in rice paddies.     

Phytotoxic sites of action for molecular design of modern herbicides (Part 2): Amino acid, lipid and cell wall biosynthesis, and other targets for future herbicides

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.     

几种除草剂靶酶及其抑制剂的研究进展

根据作用靶标对除草剂进行分类,对于新型除草剂的设计能够起到很大的帮助。迄今为止,人们已发现除草剂的不同作用位点近30种,涉及到50余种不同化学结构的化合物。文中介绍了谷氨酰胺合成酶(GS)、咪唑甘油磷酯脱水酶(IGPD)、乙酰辅酶A羧化酶(ACCace)、八氢番茄红素脱氢酶(PDS)及其各自抑制剂的研究进展。分别从酶的生理功能、酶学特征、抑制剂作用机理、抑制剂的研究、抗性等方面进行了不同程度的阐述。     

First glyphosate‐resistant Lolium spp. biotypes found in a European annual arable cropping system also affected by ACCase and ALS resistance

In Europe, glyphosate‐resistant weeds have so far only been reported in perennial crops. Following farmers' complaints of poor herbicide efficacy, resistance to glyphosate as well as to ACCase and ALS inhibitors was investigated in 11 populations of Lolium spp. collected from annual arable cropping systems in central Italy. Field histories highlighted that farmers had relied heavily on glyphosate, often at low rates, as well as in a non‐registered crop. The research aimed at elucidating the resistance status, including multiple resistance, of Lolium spp. populations through glasshouse screenings and an outdoor dose–response experiment. Target‐site resistance mechanism was also investigated for the substitutions already reported for EPSPs, ALS and ACCase genes. Three different resistant patterns were identified: glyphosate resistant only, multiple resistant to glyphosate and ACCase inhibitors and multiple resistant to glyphosate and ALS inhibitors. Amino acid substitutions were found at position 106 of the EPSPs gene, at position 1781, 2088 and 2096 of the ACCase gene and at position 197 and 574 of the ALS gene. Not all populations displayed amino acid substitutions, suggesting the presence of non‐target‐site‐mediated resistance mechanisms. After 39 years of commercial availability of glyphosate, this is the first report of multiple resistance involving glyphosate selected in annual arable crops in Europe. Management implications and options are discussed.