Target-Site Point Mutations Conferring Resistance to ACCase-Inhibiting Herbicides in Smooth Barley (Hordeum glaucum) and Hare Barley (Hordeum leporinum)

Weed Science ◽  
2015 ◽  
Vol 63 (2) ◽  
pp. 408-415 ◽  
Author(s):  
Lovreet S. Shergill ◽  
Jenna Malone ◽  
Peter Boutsalis ◽  
Christopher Preston ◽  
Gurjeet Gill
Keyword(s):  
Fatty Acid Biosynthesis ◽  
Point Mutations ◽  
Target Site ◽  
Shoot Biomass ◽  
Acid Biosynthesis ◽  
Target Site Resistance ◽  
Hordeum Leporinum ◽  
Different Populations ◽  
Acetyl Coenzyme A Carboxylase ◽  
Experienced Difficulty

Acetyl coenzyme A carboxylase (ACCase)-inhibiting herbicides affect fatty acid biosynthesis in plants and are widely used to control smooth and hare barley in dicot crops in Australia. Recently, growers have experienced difficulty in controlling smooth and hare barley with herbicides from this mode of action. Dose–response experiments conducted on five suspected resistant populations confirmed varying levels of resistance to quizalofop and haloxyfop. The level of resistance in these populations was greater than 27-fold to quizalofop and greater than 15-fold to haloxyfop. The quizalofop dose required to reduce shoot biomass by 50% (GR50) for the resistant populations varied from 52.6 to 111.9 g ha−1, and for haloxyfop from 26.5 to 71.3 g ha−1. Sequencing the CT domain of the ACCase gene from resistant plants of different populations confirmed the presence of previously known mutations Ile1781Leu and Gly2096Ala. Amino acid substitution at the 2096 position conferred a greater level of resistance to haloxyfop than the substitution at the 1781 position. This study documents the first known case of field-evolved target-site resistance to ACCase-inhibiting herbicides in Australian populations of smooth barley.

Target-Site Point Mutation Conferring Resistance to Trifluralin in Rigid Ryegrass (Lolium rigidum)

Weed Science ◽  
2017 ◽  
Vol 66 (2) ◽  
pp. 246-253 ◽  
Author(s):  
Benjamin Fleet ◽  
Jenna Malone ◽  
Christopher Preston ◽  
Gurjeet Gill
Keyword(s):  
Amino Acid ◽  
Amino Acid Substitution ◽  
Target Site ◽  
Shoot Biomass ◽  
Site Mutation ◽  
Susceptible Population ◽  
Resistant Population ◽  
Target Site Resistance ◽  
Different Populations ◽  
Rigid Ryegrass

Populations of rigid ryegrass suspected of resistance to trifluralin due to control failures exhibited varying levels of susceptibility to trifluralin, with 15 out of 17 populations deemed resistant (>20% plant survival). Detailed dose–response studies were conducted on one highly resistant field-evolved population (SLR74), one known multiply resistant population (SLR31), and one susceptible population (VLR1). On the basis of the dose required to kill 50% of treated plants (LD50), SLR74 had 15-fold greater resistance than VLR1, whereas, the multiply resistant SLR31 had 10-fold greater resistance than VLR1. Similarly, on the basis of dose required to reduce shoot biomass by 50% (GR50), SLR74 had 17-fold greater resistance than VLR1, and SLR31 had 8-fold greater resistance than VLR1. Sequencing of the α-tubulin gene from resistant plants of different populations confirmed the presence of a previously known goosegrass mutation causing an amino acid substitution at position 239 from threonine to isoleucine in resistant population SLR74. This mutation was also found in 4 out of 5 individuals in another highly resistant population TR2 and in 3 out of 5 individuals of TR4. An amino acid substitution from valine to phenylalanine at position 202 was also observed in TR4 (3 out of 5 plants) and TR2 (1 out of 5 plants). There was no target-site mutation identified in SLR31. This study documents the first known case of field-evolved target-site resistance to dinitroaniline herbicides in a population of rigid ryegrass.

scholarly journals Point Mutations and Cytochrome P450 Can Contribute to Resistance to ACCase-Inhibiting Herbicides in Three Phalaris Species

Plants ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1703
Author(s):  
José G. Vázquez-García ◽  
Joel Torra ◽  
Candelario Palma-Bautista ◽  
Ricardo Alcántara-de la Cruz ◽  
Rafael De Prado
Keyword(s):  
Point Mutations ◽  
Resistance Mechanisms ◽  
Target Site ◽  
In Vitro Assays ◽  
Cross Resistance ◽  
Northern Iran ◽  
Target Site Resistance ◽  
Acetyl Coenzyme A Carboxylase ◽  
Selection Of

Species of Phalaris have historically been controlled by acetyl-coenzyme A carboxylase (ACCase)-inhibiting herbicides; however, overreliance on herbicides with this mechanism of action has resulted in the selection of resistant biotypes. The resistance to ACCase-inhibiting herbicides was characterized in Phalaris brachystachys, Phalaris minor, and Phalaris paradoxa samples collected from winter wheat fields in northern Iran. Three resistant (R) biotypes, one of each Phalaris species, presented high cross-resistance levels to diclofop-methyl, cycloxydim, and pinoxaden, which belong to the chemical families of aryloxyphenoxypropionates (FOPs), cyclohexanediones (DIMs), and phenylpyrazolines (DENs), respectively. The metabolism of 14C-diclofop-methyl contributed to the resistance of the P. brachystachys R biotype, while no evidence of herbicide metabolism was found in P. minor or P. paradoxa. ACCase in vitro assays showed that the target sites were very sensitive to FOP, DIM, and DEN herbicides in the S biotypes of the three species, while the R Phalaris spp. biotypes presented different levels of resistance to these herbicides. ACCase gene sequencing confirmed that cross-resistance in Phalaris species was conferred by specific point mutations. Resistance in the P. brachystachys R biotype was due to target site and non-target-site resistance mechanisms, while in P. minor and P. paradoxa, only an altered target site was found.

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 Polyclonal-Based ELISA for the Identification of Cyclohexanedione Analogs that Inhibit Maize Acetyl Coenzyme-A Carboxylase

2001 ◽  
Vol 84 (1) ◽  
pp. 143-149 ◽  
Author(s):  
Steven R Webb ◽  
J Christopher Hall
Keyword(s):  
Fatty Acid Biosynthesis ◽  
Coenzyme A ◽  
Immunological Study ◽  
Acid Biosynthesis ◽  
Acetyl Coenzyme A ◽  
Acetyl Coenzyme ◽  
New Zealand White Rabbits ◽  
Bovine Serum Albumin Conjugate ◽  
Herbicide Binding ◽  
Acetyl Coenzyme A Carboxylase

Abstract Cyclohexanedione herbicides inhibit monocotyledonous acetyl coenzyme-A carboxylase (ACCase; E.C. 6.4.1.2.), which catalyzes the first committed step in fatty acid biosynthesis. Although the target site has been identified, little is known about the mechanisms involved in herbicide binding. An immunological study was undertaken to create a model to better characterize the herbicide–enzyme interaction. Cyclohexanedione-specific antiserum was raised in New Zealand white rabbits by immunizing them with a cyclohexanedione analog–bovine serum albumin conjugate. Two indirect enzyme-linked immunosorbent assays (ELISA) were developed using 2 different cyclohexanedione analogs conjugated to ovalbumin as coating conjugates. Nineteen cyclohexanedione analogs, 13 active ACCase inhibitors, and 6 inactive analogs were tested for their ability to compete with both coating conjugates for antiserum binding. All active ACCase inhibitors were observed to compete with both coating conjugates, whereas all inactive analogs failed to compete with at least one coating conjugate. On the basis of these results, the immunological model could be used to distinguish all active ACCase inhibitors from inactive analogs using the 2 ELISAs sequentially.

scholarly journals Inhibition of Acetyl Coenzyme A Carboxylase Activity Restores Expression of the INO1 Gene in a snf1Mutant Strain of Saccharomyces cerevisiae

2001 ◽  
Vol 21 (17) ◽  
pp. 5710-5722 ◽  
Author(s):  
Margaret K. Shirra ◽  
Jana Patton-Vogt ◽  
Andreas Ulrich ◽  
Oksana Liuta-Tehlivets ◽  
Sepp D. Kohlwein ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Fatty Acid ◽  
Fatty Acid Biosynthesis ◽  
Coenzyme A ◽  
Phospholipid Biosynthesis ◽  
Acid Biosynthesis ◽  
Acetyl Coenzyme A ◽  
Acetyl Coenzyme ◽  
Soraphen A ◽  
Acetyl Coenzyme A Carboxylase

ABSTRACT Mutations in the Saccharomyces cerevisiae SNF1 gene affect a number of cellular processes, including the expression of genes involved in carbon source utilization and phospholipid biosynthesis. To identify targets of the Snf1 kinase that modulate expression of INO1, a gene required for an early, rate-limiting step in phospholipid biosynthesis, we performed a genetic selection for suppressors of the inositol auxotrophy ofsnf1Δ strains. We identified mutations inACC1 and FAS1, two genes important for fatty acid biosynthesis in yeast; ACC1 encodes acetyl coenzyme A carboxylase (Acc1), and FAS1 encodes the β subunit of fatty acid synthase. Acc1 was shown previously to be phosphorylated and inactivated by Snf1. Here we show thatsnf1Δ strains with increased Acc1 activity exhibit decreased INO1 transcription. Strains carrying theACC1 suppressor mutation have reduced Acc1 activity in vitro and in vivo, as revealed by enzymatic assays and increased sensitivity to the Acc1-specific inhibitor soraphen A. Moreover, a reduction in Acc1 activity, caused by addition of soraphen A, provision of exogenous fatty acid, or conditional expression ofACC1, suppresses the inositol auxotrophy ofsnf1Δ strains. Together, these findings indicate that the inositol auxotrophy of snf1Δ strains arises in part from elevated Acc1 activity and that a reduction in this activity restores INO1 expression in these strains. These results reveal a Snf1-dependent connection between fatty acid production and phospholipid biosynthesis, identify Acc1 as a Snf1 target important forINO1 transcription, and suggest models in which metabolites that are generated or utilized during fatty acid biosynthesis can significantly influence gene expression in yeast.

scholarly journals Fitness costs of key point mutations that underlie acaricide target-site resistance in the two-spotted spider miteTetranychus urticae

2018 ◽  
Vol 11 (9) ◽  
pp. 1540-1553 ◽  
Author(s):  
Sabina Bajda ◽  
Maria Riga ◽  
Nicky Wybouw ◽  
Stavrini Papadaki ◽  
Eleni Ouranou ◽  
...  
Keyword(s):  
Point Mutations ◽  
Target Site ◽  
Fitness Costs ◽  
Target Site Resistance

Characterization of Fenoxaprop-P-Ethyl–Resistant Junglerice (Echinochloa colona) from Mississippi

Weed Science ◽  
2016 ◽  
Vol 64 (4) ◽  
pp. 588-595 ◽  
Author(s):  
Alice A. Wright ◽  
Vijay K. Nandula ◽  
Logan Grier ◽  
Kurt C. Showmaker ◽  
Jason A. Bond ◽  
...  
Keyword(s):  
Coenzyme A ◽  
Point Mutations ◽  
Target Site ◽  
Acetyl Coenzyme A ◽  
Acetyl Coenzyme ◽  
Resistant Population ◽  
Sunflower County ◽  
Acetyl Coenzyme A Carboxylase ◽  
P450 Inhibitors

A population of junglerice from Sunflower County, MS, exhibited resistance to fenoxaprop-P-ethyl. An 11-fold difference in ED50 (the effective dose needed to reduce growth by 50%) values was observed when comparing the resistant population (249 g ae ha–1) with susceptible plants (20 g ae ha–1) collected from a different field. The resistant population was controlled by clethodim and sethoxydim at the field rate. Sequencing of the acetyl coenzyme A carboxylase, which encodes the enzyme targeted by fenoxaprop-P-ethyl, did not reveal the presence of any known resistance-conferring point mutations. An enzyme assay confirmed that the acetyl coenzyme A carboxylase in the resistant population is herbicide sensitive. Further investigations with two cytochrome P450 inhibitors, malathion and piperonyl butoxide, and a glutathione-S-transferase inhibitor, 4-chloro-7-nitrobenzofurazan, did not indicate involvement of any metabolic enzymes inhibited by these compounds. The absence of a known target-site point mutation and the sensitivity of the ACCase enzyme to herbicide show that fenoxaprop-P-ethyl resistance in this population is due to a non–target-site mechanism or mechanisms.

scholarly journals Fatty Acid Biosynthesis in Mitochondria of Grasses: Malonyl-Coenzyme A Is Generated by a MitochondrialLocalized Acetyl-Coenzyme A Carboxylase

2003 ◽  
Vol 133 (2) ◽  
pp. 875-884 ◽  
Author(s):  
Manfred Focke ◽  
Ellen Gieringer ◽  
Sabine Schwan ◽  
Lothar Jänsch ◽  
Stefan Binder ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Fatty Acid Biosynthesis ◽  
Coenzyme A ◽  
Acid Biosynthesis ◽  
Acetyl Coenzyme A ◽  
Acetyl Coenzyme ◽  
Acetyl Coenzyme A Carboxylase
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