scholarly journals A high diversity of mechanisms endows ALS-inhibiting herbicide resistance in the invasive common ragweed (Ambrosia artemisiifolia L.)

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ingvild Loubet ◽  
Laëtitia Caddoux ◽  
Séverine Fontaine ◽  
Séverine Michel ◽  
Fanny Pernin ◽  
...  
Keyword(s):  
Resistance Mechanism ◽  
Resistance Management ◽  
Genotyping By Sequencing ◽  
Ambrosia Artemisiifolia ◽  
Target Site ◽  
Major Type ◽  
Common Ragweed ◽  
Resistance Evolution ◽  
Arable Weed ◽  
Target Site Resistance

AbstractAmbrosia artemisiifolia L. (common ragweed) is a globally invasive, allergenic, troublesome arable weed. ALS-inhibiting herbicides are broadly used in Europe to control ragweed in agricultural fields. Recently, ineffective treatments were reported in France. Target site resistance (TSR), the only resistance mechanism described so far for ragweed, was sought using high-throughput genotyping-by-sequencing in 213 field populations randomly sampled based on ragweed presence. Additionally, non-target site resistance (NTSR) was sought and its prevalence compared with that of TSR in 43 additional field populations where ALS inhibitor failure was reported, using herbicide sensitivity bioassay coupled with ALS gene Sanger sequencing. Resistance was identified in 46 populations and multiple, independent resistance evolution demonstrated across France. We revealed an unsuspected diversity of ALS alleles underlying resistance (9 amino-acid substitutions involved in TSR detected across 24 populations). Remarkably, NTSR was ragweed major type of resistance to ALS inhibitors. NTSR was present in 70.5% of the resistant plants and 74.1% of the fields harbouring resistance. A variety of NTSR mechanisms endowing different resistance patterns evolved across populations. Our study provides novel data on ragweed resistance to herbicides, and emphasises that local resistance management is as important as mitigating gene flow from populations where resistance has arisen.

Confirmation and Resistance Mechanisms in Glyphosate-Resistant Common Ragweed (Ambrosia artemisiifolia) in Arkansas

Weed Science ◽  
2009 ◽  
Vol 57 (6) ◽  
pp. 567-573 ◽  
Author(s):  
Chad E. Brewer ◽  
Lawrence R. Oliver
Keyword(s):  
Resistance Mechanism ◽  
Population Data ◽  
Glyphosate Resistance ◽  
Population Based ◽  
Resistance Mechanisms ◽  
Ambrosia Artemisiifolia ◽  
Target Site ◽  
Susceptible Population ◽  
Common Ragweed

Greenhouse studies were established in Fayetteville, AR, to investigate glyphosate resistance in Arkansas common ragweed populations. Common ragweed seed were collected from plants in Pope and Jackson counties in Arkansas. Plants grown from seed were sprayed with one of seven glyphosate rates. Populations in Pope and Jackson counties were 21-fold and 10-fold more tolerant to glyphosate, respectively, than a known susceptible population. Based on14C-glyphosate absorption and translocation studies, reduced glyphosate absorption or translocation was not the resistance mechanism in Arkansas glyphosate-resistant common ragweed. Shikimate accumulation did not differ among the known susceptible and the two resistant populations at 3 d after treatment (DAT). However, by 5 DAT, shikimate accumulation in the two resistant populations was lower than the known susceptible population. Data indicate that glyphosate-resistant common ragweed is present in at least two locations in Arkansas, and the resistance mechanism is not an insensitive target site or reduced glyphosate absorption or translocation.

Evolution of target and non-target based multiple herbicide resistance in a single Palmer amaranth (Amaranthus palmeri) population from Kansas

2020 ◽  
Vol 34 (3) ◽  
pp. 447-453
Author(s):  
Sushila Chaudhari ◽  
Vijay K. Varanasi ◽  
Sridevi Nakka ◽  
Prasanta C. Bhowmik ◽  
Curtis R. Thompson ◽  
...  
Keyword(s):  
Resistance Mechanism ◽  
Acetolactate Synthase ◽  
Palmer Amaranth ◽  
Target Site ◽  
Epsp Synthase ◽  
High Incidence ◽  
Evolution Of Resistance ◽  
Target Site Resistance ◽  
Herbicide Atrazine ◽  
Sites Of Action

AbstractThe evolution of resistance to multiple herbicides in Palmer amaranth is a major challenge for its management. In this study, a Palmer amaranth population from Hutchinson, Kansas (HMR), was characterized for resistance to inhibitors of photosystem II (PSII) (e.g., atrazine), acetolactate synthase (ALS) (e.g., chlorsulfuron), and EPSP synthase (EPSPS) (e.g., glyphosate), and this resistance was investigated. About 100 HMR plants were treated with field-recommended doses (1×) of atrazine, chlorsulfuron, and glyphosate, separately along with Hutchinson multiple-herbicide (atrazine, chlorsulfuron, and glyphosate)–susceptible (HMS) Palmer amaranth as control. The mechanism of resistance to these herbicides was investigated by sequencing or amplifying the psbA, ALS, and EPSPS genes, the molecular targets of atrazine, chlorsulfuron, and glyphosate, respectively. Fifty-two percent of plants survived a 1× (2,240 g ai ha−1) atrazine application with no known psbA gene mutation, indicating the predominance of a non–target site resistance mechanism to this herbicide. Forty-two percent of plants survived a 1× (18 g ai ha−1) dose of chlorsulfuron with proline197serine, proline197threonine, proline197alanine, and proline197asparagine, or tryptophan574leucine mutations in the ALS gene. About 40% of the plants survived a 1× (840 g ae ha−1) dose of glyphosate with no known mutations in the EPSPS gene. Quantitative PCR results revealed increased EPSPS copy number (50 to 140) as the mechanism of glyphosate resistance in the survivors. The most important finding of this study was the evolution of resistance to at least two sites of action (SOAs) (~50% of plants) and to all three herbicides due to target site as well as non–target site mechanisms. The high incidence of individual plants with resistance to multiple SOAs poses a challenge for effective management of this weed.

scholarly journals Point Mutations as Main Resistance Mechanism Together With P450-Based Metabolism Confer Broad Resistance to Different ALS-Inhibiting Herbicides in Glebionis coronaria From Tunisia

2021 ◽  
Vol 12 ◽  
Author(s):  
Zeineb Hada ◽  
Yosra Menchari ◽  
Antonia M. Rojano-Delgado ◽  
Joel Torra ◽  
Julio Menéndez ◽  
...  
Keyword(s):  
Enzyme Activity ◽  
Dose Response ◽  
Resistance Mechanism ◽  
Point Mutations ◽  
Acetolactate Synthase ◽  
Target Site ◽  
Cross Resistance ◽  
P450 Monooxygenase ◽  
Target Site Resistance ◽  
Sites Of Action

Resistance to acetolactate synthase (ALS) inhibiting herbicides has recently been reported in Glebionis coronaria from wheat fields in northern Tunisia, where the weed is widespread. However, potential resistance mechanisms conferring resistance in these populations are unknown. The aim of this research was to study target-site resistance (TSR) and non-target-site resistance (NTSR) mechanisms present in two putative resistant (R) populations. Dose–response experiments, ALS enzyme activity assays, ALS gene sequencing, absorption and translocation experiments with radiolabeled herbicides, and metabolism experiments were carried out for this purpose. Whole plant trials confirmed high resistance levels to tribenuron and cross-resistance to florasulam and imazamox. ALS enzyme activity further confirmed cross-resistance to these three herbicides and also to bispyribac, but not to flucarbazone. Sequence analysis revealed the presence of amino acid substitutions in positions 197, 376, and 574 of the target enzyme. Among the NTSR mechanisms investigated, absorption or translocation did not contribute to resistance, while evidences of the presence of enhanced metabolism were provided. A pretreatment with the cytochrome P450 monooxygenase (P450) inhibitor malathion partially synergized with imazamox in post-emergence but not with tribenuron in dose–response experiments. Additionally, an imazamox hydroxyl metabolite was detected in both R populations in metabolism experiments, which disappeared with the pretreatment with malathion. This study confirms the evolution of cross-resistance to ALS inhibiting herbicides in G. coronaria from Tunisia through TSR and NTSR mechanisms. The presence of enhanced metabolism involving P450 is threatening the chemical management of this weed in Tunisian wheat fields, since it might confer cross-resistance to other sites of action.

scholarly journals Target-Site Resistances to ALS and PPO Inhibitors Are Linked in Waterhemp (Amaranthus tuberculatus)

Weed Science ◽  
2016 ◽  
Vol 65 (1) ◽  
pp. 4-8 ◽  
Author(s):  
Patrick J. Tranel ◽  
Chenxi Wu ◽  
Ahmed Sadeque
Keyword(s):  
Resistance Mechanism ◽  
Acetolactate Synthase ◽  
Resistance Mechanisms ◽  
Target Site ◽  
Recurrent Parent ◽  
Common Waterhemp ◽  
Independent Assortment ◽  
Resistance Evolution ◽  
Amaranthus Tuberculatus ◽  
Molecular Marker Analysis

It is generally expected that, in the case of multiple herbicide resistance, different resistance mechanisms within a weed will follow Mendel’s law of independent assortment. Research was conducted to investigate anecdotal observations suggesting that target site–based resistances to inhibitors of acetolactate synthase (ALS) and protoporphyrinogen oxidase (PPO) did not follow independent assortment in common waterhemp. Cosegregation of the two resistances was observed in backcross lines (population sensitive to both herbicides as recurrent parent). Specifically, whereas 52% of backcross plants were resistant to a PPO inhibitor, this percentage increased to 92% when the backcross plants were preselected for resistance to an ALS inhibitor. Molecular marker analysis confirmed that the corresponding genes (ALSandPPX2) were genetically linked. When data from all plants analyzed were pooled, the genetic distance between the two genes was calculated to be 7.5 cM. The two genes were found to be about 195 kb apart in the recently published grain amaranth genome, explaining the observed genetic linkage. There is likely enough recombination that occurs between the linked genes to prevent the linkage from having significant implications in terms of resistance evolution. Nevertheless, documentation of the happenstance linkage between target-site genes for resistance to ALS and PPO inhibitors in waterhemp is a reminder that one should not assume distinct resistance mechanism will independently assort.

Aerobic Metabolism Alterations as an Evidence of Underlying Deltamethrin Resistance Mechanisms in Triatoma infestans (Hemiptera: Reduviidae)

2020 ◽  
Vol 57 (6) ◽  
pp. 1988-1991
Author(s):  
Carmen Rolandi ◽  
Gonzalo Roca-Acevedo ◽  
Pablo E Schilman ◽  
Mónica D Germano
Keyword(s):  
Resistance Mechanism ◽  
Resistance Management ◽  
Resistance Mechanisms ◽  
Target Site ◽  
Triatoma Infestans ◽  
Co2 Production ◽  
Mechanisms Of Resistance ◽  
Metabolic Resistance ◽  
Open Flow ◽  
Deltamethrin Resistance

Abstract Triatoma infestans (Klug, 1834), the main vector of Chagas disease in Latin America, is regularly controlled by spraying the pyrethroid deltamethrin, to which some populations have developed resistance. The three main mechanisms of resistance are 1) metabolic resistance by overexpression or increased activity of detoxifying enzymes, 2) target site mutations, and 3) cuticle thickening/modification. We use open-flow respirometry to measure real-time H2O loss rate (V˙H2O) and CO2 production rate (V˙CO2), on nymphs from susceptible and resistant populations before and after exposure to the insecticide to understand the underlying mechanisms of resistance in live insects. Lack of differences in V˙H2O between populations suggested that cuticular thickness/composition is not acting as a relevant resistance mechanism. Similarly, there was no difference in resting V˙CO2, suggesting a trade-off between resistance mechanisms and other physiological processes. The increment in V˙CO2 after application of deltamethrin was similar in both populations, which suggested that while enhanced enzymatic detoxification may play a role in resistance expression in this population, the main mechanism involved should be a passive one such as target site mutations. Open-flow respirometry provided useful evidence for evaluating the mechanisms involved in deltamethrin resistance. Using this technique could improve efficiency of scientific research in the area of insecticide resistance management, leading to a faster decision making and hence improved control results.

Association of the W574L ALS substitution with resistance to cloransulam and imazamox in common ragweed (Ambrosia artemisiifolia)

Weed Science ◽  
2005 ◽  
Vol 53 (4) ◽  
pp. 424-430 ◽  
Author(s):  
Danman Zheng ◽  
William L. Patzoldt ◽  
Patrick J. Tranel
Keyword(s):  
Acetolactate Synthase ◽  
Dry Weight ◽  
Ambrosia Artemisiifolia ◽  
Target Site ◽  
Common Ragweed ◽  
Chain Reactions ◽  
Polymerase Chain Reactions ◽  
Allele Specific ◽  
Treated Plant ◽  
Als Inhibitors

Previous research revealed that resistance to cloransulam in at least one population of common ragweed was conferred by an altered herbicide target site, specifically, by a tryptophan-to-leucine amino acid substitution at position 574 (W574L) of acetolactate synthase (ALS). In this study, 22 common ragweed populations, several of which were suspected cloransulam resistant, were assayed to determine if the W574L ALS substitution was correlated with resistance to ALS inhibitors. From each population, 16 greenhouse-grown plants were treated with cloransulam, and another 16 were treated with imazamox. Plant dry weights were recorded 20 d after treatment and individual plants were considered resistant if their dry weight exceeded 50% of that of nonherbicide-treated controls. For each herbicide-treated plant, allele-specific primers were used in polymerase chain reactions to determine whether the ALS alleles contained leucine or tryptophan codons at position 574. Of the 352 plants treated with cloransulam, 70 were determined to be resistant, and all but two contained one or more Leu574alleles. The frequency of imazamox resistance was much higher than that of cloransulam in the populations, with 149 of 352 plants identified as imazamox resistant. However, only about half (80) of the imazamox-resistant plants contained one or more Leu574alleles. Correlation of imazamox resistance and Leu574alleles was population dependent. ALS activity assays confirmed that imazamox resistance in plants from at least one population was due to an altered target site, even though plants from that population did not have a W574L substitution. These results lead to the conclusion that a Leu574allele is the predominant basis for cloransulam resistance in common ragweed; however, other mechanisms of resistance to ALS inhibitors exist in some populations.

scholarly journals ‘What I cannot create, I do not understand’: functionally validated synergism of metabolic and target site insecticide resistance

2020 ◽  
Vol 287 (1927) ◽  
pp. 20200838 ◽  
Author(s):  
George-Rafael Samantsidis ◽  
Rafaela Panteleri ◽  
Shane Denecke ◽  
Stella Kounadi ◽  
Iason Christou ◽  
...  
Keyword(s):  
Insecticide Resistance ◽  
Crop Production ◽  
Pyrethroid Resistance ◽  
Malaria Incidence ◽  
Resistance Management ◽  
Underlying Mechanism ◽  
Target Site ◽  
Pollen Beetle ◽  
Brassicogethes Aeneus ◽  
Target Site Resistance

The putative synergistic action of target-site mutations and enhanced detoxification in pyrethroid resistance in insects has been hypothesized as a major evolutionary mechanism responsible for dramatic consequences in malaria incidence and crop production. Combining genetic transformation and CRISPR/Cas9 genome modification, we generated transgenic Drosophila lines expressing pyrethroid metabolizing P450 enzymes in a genetic background along with engineered mutations in the voltage-gated sodium channel ( para ) known to confer target-site resistance. Genotypes expressing the yellow fever mosquito Aedes aegypti Cyp9J28 while also bearing the para V1016G mutation displayed substantially greater resistance ratio (RR) against deltamethrin than the product of each individual mechanism (RR combined : 19.85 > RR Cyp9J28 : 1.77 × RR V1016G : 3.00). Genotypes expressing Brassicogethes aeneus pollen beetle Cyp6BQ23 and also bearing the para L1014F ( kdr ) mutation, displayed an almost multiplicative RR (RR combined : 75.19 ≥ RR Cyp6BQ23 : 5.74 × RR L1014F : 12.74). Reduced pyrethroid affinity at the target site, delaying saturation while simultaneously extending the duration of P450-driven detoxification, is proposed as a possible underlying mechanism. Combinations of target site and P450 resistance loci might be unfavourable in field populations in the absence of insecticide selection, as they exert some fitness disadvantage in development time and fecundity. These are major considerations from the insecticide resistance management viewpoint in both public health and agriculture.

Molecular confirmation of resistance to PPO inhibitors in Amaranthus tuberculatus and Amaranthus palmeri, and isolation of the G399A PPO2 substitution in A. palmeri

2020 ◽  
pp. 1-7
Author(s):  
Jacob S. Montgomery ◽  
Darci A. Giacomini ◽  
Patrick J. Tranel
Keyword(s):  
Goodness Of Fit ◽  
Resistance Mechanism ◽  
Amino Acid Position ◽  
Resistance Mechanisms ◽  
Palmer Amaranth ◽  
Target Site ◽  
Coding Region ◽  
Common Waterhemp ◽  
Growing Seasons ◽  
Target Site Resistance

Abstract During the 2017 to 2019 growing seasons, samples of waterhemp and Palmer amaranth that had reportedly survived field-rate applications of protoporphyrinogen oxidase (PPO)–inhibiting herbicides were collected from the American Midwest and tested for target-site mutations known at the time to confer resistance. Target-site resistance was identified in nearly all (135 of 145) tested common waterhemp populations but in only 8 of 13 Palmer amaranth populations. Follow-up research on one population of Palmer amaranth (W-8), which tested negative for all such mutations, confirmed it was resistant to lactofen, with a magnitude of resistance comparable to that conferred by the ΔG210 PPO2 mutation. Gene sequences from both isoforms of PPO (PPO1 and PPO2) were compared between W-8 and known PPO inhibitor–sensitive sequence. A glycine-to-alanine substitution at the 399th amino acid position (G399A) of PPO2, recently identified to reduce target-site herbicide sensitivity, was observed in a subset of resistant W-8 plants. Because no missense mutation completely delimited resistant and sensitive sequences, we initially suspected the presence of a secondary, non-target-site resistance mechanism in this population. To isolate G399A, a segregating F2 population was produced and screened with a delimiting rate of lactofen. χ2 goodness-of-fit analysis of dead/alive ratings indicated single-locus inheritance of resistance in the F2 population, and molecular markers for the W-8 parental PPO2 coding region co-segregated tightly, but not perfectly, with resistance. More research is needed to fully characterize Palmer amaranth PPO inhibitor–resistance mechanisms, which appear to be more diverse than those found in common waterhemp.

scholarly journals Weed resistance to herbicides

2020 ◽  
Vol 29 (2) ◽  
pp. 79-96
Author(s):  
Sava Vrbničanin
Keyword(s):  
Herbicide Resistance ◽  
Amaranthus Retroflexus ◽  
Ambrosia Artemisiifolia ◽  
Target Site ◽  
Weed Species ◽  
Ps Ii ◽  
Target Site Resistance ◽  
Resistance To Herbicides ◽  
Als Inhibitors ◽  
Weed Resistance

Weed resistance to herbicides represents the acquired resistance of individuals to complete the life cycle and leave offspring in the conditions of extended exposure to the same herbicide, i.e. herbicides of the same mechanism of action to which they were sensitive at the beginning of the application. Based on the herbicide resistance mechanisms, all processes can be grouped as follows: target-site resistance, non-target-site resistance, cross-resistance and multiple-resistance. Currently, herbicide resistance has been reported in 514 cases (species x site of action) worldwide, in 262 weed species (152 dicotyledons, 110 monocotyledons). Many of those biotypes are resistant to als inhibitors, PS II inhibitors, EPSPS inhibitors and ACC-ase inhibitors. The higher degree of resistance to als inhibitors has been confirmed in the following weed species: Amaranthus retroflexus, Sorghum halepense, Ambrosia artemisiifolia and Helianthus annuus.

Sign in / Sign up

Export Citation Format

Share Document