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1.
Methods Mol Biol ; 2638: 373-385, 2023.
Article in English | MEDLINE | ID: mdl-36781657

ABSTRACT

The derived polymorphic amplified cleaved sequence (dPACS) assay is a simple polymerase chain reaction/restriction fragment length polymorphism (PCR-RFLP)-based procedure for detecting known single-nucleotide polymorphisms (SNPs) and deletion-insertion polymorphisms (DIPs). It is relatively straightforward to carry out using basic and commonly available molecular biology kits. The method differs from other PCR-RFLP assays in that it employs 35-55 bp primer pairs that encompass the entire targeted DNA region except for a few diagnostic nucleotides being examined. In so doing, it allows for the introduction of nucleotide mismatches in one or both primers for differentiating wild from mutant sequences following polymerase chain reaction, restriction digestion and MetaPhor gel electrophoresis. Primer design and the selection of discriminating enzymes are achieved with the help of the dPACS 1.0 program. The method is exemplified here with the positive detection of serine 264-psbA, a key determinant for the effective binding of some photosystem II inhibitors to their target. A serine-to-glycine mutation at codon 264 of psbA causes resistance to serine-binding photosystem II herbicides in several grasses and broad-leaf weeds, including Amaranthus retroflexus, which is employed in this study.


Subject(s)
Photosystem II Protein Complex , Photosystem II Protein Complex/genetics , Polymorphism, Restriction Fragment Length , Mutation , Polymerase Chain Reaction/methods , Codon
2.
Cureus ; 14(6): e25788, 2022 Jun.
Article in English | MEDLINE | ID: mdl-35812537

ABSTRACT

Diabetic ketoacidosis (DKA) is a serious diabetic complication that is characterized by hyperglycemia, metabolic acidosis, and ketosis. A subset of DKA patients may present with blood glucose levels <250 mg/dL which may delay the diagnosis. This subset is referred to as euglycemic DKA (euDKA). It is generally seen in pregnancy, prolonged fasting, and the use of sodium-glucose cotransporter 2 (SGLT2) inhibitors. The recent rise in the use of SGLT2 inhibitors to treat diabetes has increased the incidence of euDKA. We present the case of a 60-year-old female on SGLT2 inhibitors who presented after a ground-level fall and was not diagnosed with euDKA until the next morning. This case was further complicated by another episode of euDKA during the same admission, suggesting that euDKA is possible even after holding the SGLT2 inhibitors for a few days.

3.
Genes (Basel) ; 12(11)2021 11 21.
Article in English | MEDLINE | ID: mdl-34828444

ABSTRACT

Herbicides that inhibit acetyl-CoA carboxylase (ACCase) are among the few remaining options for the post-emergence control of Lolium species in small grain cereal crops. Here, we determined the mechanism of resistance to ACCase herbicides in a Lolium multiflorum population (HGR) from France. A combined biological and molecular approach detected a novel W2027L ACCase mutation that affects aryloxyphenoxypropionate (FOP) but not cyclohexanedione (DIM) or phenylpyraxoline (DEN) subclasses of ACCase herbicides. Both the wild-type tryptophan and mutant leucine 2027-ACCase alleles could be positively detected in a single DNA-based-derived polymorphic amplified cleaved sequence (dPACS) assay that contained the targeted PCR product and a cocktail of two discriminating restriction enzymes. Additionally, we identified three well-characterised I1781L, I2041T, and D2078G ACCase target site resistance mutations as well as non-target site resistance in HGR. The non-target site component endowed high levels of resistance to FOP herbicides whilst partially impacting on the efficacy of pinoxaden and cycloxydim. This study adequately assessed the contribution of the W2027L mutation and non-target site mechanism in conferring resistance to ACCase herbicides in HGR. It also highlights the versatility and robustness of the dPACS method to simultaneously identify different resistance-causing alleles at a single ACCase codon.


Subject(s)
Acetyl-CoA Carboxylase/genetics , Herbicide Resistance , Lolium/genetics , Mutation, Missense , Acetyl-CoA Carboxylase/antagonists & inhibitors , Acetyl-CoA Carboxylase/chemistry , Acetyl-CoA Carboxylase/metabolism , Binding Sites , Enzyme Inhibitors/toxicity , Herbicides/toxicity , Lolium/drug effects , Protein Binding
4.
Cureus ; 13(10): e18656, 2021 Oct.
Article in English | MEDLINE | ID: mdl-34790442

ABSTRACT

Colorectal cancer is the second leading cause of cancer deaths in the United States. Familial adenomatosis polyposis (FAP) is a rare cause of colorectal cancer. The United States Preventive Services Task Force (USPSTF) recommends screening for colorectal cancer in average-risk, asymptomatic adults aged 50 to 75 years. While age is the most important risk factor, we need to consider the family history of colorectal cancer. FAP is a rare cause of colorectal cancer, leading to high morbidity and mortality if undetected and undiagnosed. It is easy to overlook the family history in a busy primary care clinic with limited patient encounter times. Clinicians mustn't forget this important piece of information as it can give leads for further patient evaluation. We present a case report of a 21-year-old male who presented to our clinic to establish primary care and with vague abdominal complaints. Still, the concerning family history of early onset colon cancer in his half-sister raised red flags and directed us to further evaluate. Further evaluation revealed our patient, in fact, had FAP.

5.
New Phytol ; 232(5): 2089-2105, 2021 12.
Article in English | MEDLINE | ID: mdl-34480751

ABSTRACT

Metabolic resistance to 4-hydroxyphenylpyruvate dioxygenase (HPPD)-inhibiting herbicides is a threat in controlling waterhemp (Amaranthus tuberculatus) in the USA. We investigated resistance mechanisms to syncarpic acid-3 (SA3), a nonselective, noncommercial HPPD-inhibiting herbicide metabolically robust to Phase I oxidation, in multiple-herbicide-resistant (MHR) waterhemp populations (SIR and NEB) and HPPD inhibitor-sensitive populations (ACR and SEN). Dose-response experiments with SA3 provided ED50 -based resistant : sensitive ratios of at least 18-fold. Metabolism experiments quantifying parent SA3 remaining in excised leaves during a time course indicated MHR populations displayed faster rates of SA3 metabolism compared to HPPD inhibitor-sensitive populations. SA3 metabolites were identified via LC-MS-based untargeted metabolomics in whole plants. A Phase I metabolite, likely generated by cytochrome P450-mediated alkyl hydroxylation, was detected but was not associated with resistance. A Phase I metabolite consistent with ketone reduction followed by water elimination was detected, creating a putative α,ß-unsaturated carbonyl resembling a Michael acceptor site. A Phase II glutathione-SA3 conjugate was associated with resistance. Our results revealed a novel reduction-dehydration-GSH conjugation detoxification mechanism. SA3 metabolism in MHR waterhemp is thus atypical compared to commercial HPPD-inhibiting herbicides. This previously uncharacterized detoxification mechanism presents a unique opportunity for future biorational design by blocking known sites of herbicide metabolism in weeds.


Subject(s)
4-Hydroxyphenylpyruvate Dioxygenase , Amaranthus , Dioxygenases , Herbicides , Dehydration , Glutathione , Herbicide Resistance , Herbicides/pharmacology
6.
Front Plant Sci ; 12: 651381, 2021.
Article in English | MEDLINE | ID: mdl-34267768

ABSTRACT

The evolution of resistance to pesticides in agricultural systems provides an opportunity to study the fitness costs and benefits of novel adaptive traits. Here, we studied a population of Amaranthus tuberculatus (common waterhemp), which has evolved resistance to glyphosate. The growth and fitness of seed families with contrasting levels of glyphosate resistance was assessed in the absence of glyphosate to determine their ability to compete for resources under intra- and interspecific competition. We identified a positive correlation between the level of glyphosate resistance and gene copy number for the 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) glyphosate target, thus identifying gene amplification as the mechanism of resistance within the population. Resistant A. tuberculatus plants were found to have a lower competitive response when compared to the susceptible phenotypes with 2.76 glyphosate resistant plants being required to have an equal competitive effect as a single susceptible plant. A growth trade-off was associated with the gene amplification mechanism under intra-phenotypic competition where 20 extra gene copies were associated with a 26.5 % reduction in dry biomass. Interestingly, this growth trade-off was mitigated when assessed under interspecific competition from maize.

7.
Appl Clin Inform ; 12(2): 329-339, 2021 03.
Article in English | MEDLINE | ID: mdl-33882586

ABSTRACT

OBJECTIVE: The objective of the study was to highlight and analyze the outcomes of software configuration requests received from Sprint, a comprehensive, clinic-centered electronic health record (EHR) optimization program. METHODS: A retrospective review of 1,254 Sprint workbook requests identified (1) the responsible EHR team, (2) the clinical efficiency gained from the request, and (3) the EHR intervention conducted. RESULTS: Requests were received from 407 clinicians and 538 staff over 31 weeks of Sprint. Sixty-nine percent of the requests were completed during the Sprint. Of all requests, 25% required net new build, 73% required technical investigation and/or solutions, and 2% of the requests were escalated to the vendor. The clinical specialty groups requested a higher percentage of items that earned them clinical review (16 vs. 10%) and documentation (29 vs. 23%) efficiencies compared with their primary care colleagues who requested slightly more order modifications (22 vs. 20%). Clinical efficiencies most commonly associated with workbook requests included documentation (28%), ordering (20%), in basket (17%), and clinical review (15%). Sprint user requests evaluated by ambulatory, hardware, security, and training teams comprised 80% of reported items. DISCUSSION: Sprint requests were categorized as clean-up, break-fix, workflow investigation, or new build. On-site collaboration with clinical care teams permitted consensus-building, drove vetting, and iteration of EHR build, and led to goal-driven, usable workflows and EHR products. CONCLUSION: This program evaluation demonstrates the process by which optimization can occur and the products that result when we adhere to optimization principles in health care organizations.


Subject(s)
Documentation , Electronic Health Records , Humans , Primary Health Care , Retrospective Studies , Workflow
8.
Sci Rep ; 10(1): 20741, 2020 11 26.
Article in English | MEDLINE | ID: mdl-33244093

ABSTRACT

Agricultural weeds can adapt rapidly to human activities as exemplified by the evolution of resistance to herbicides. Despite its multi-faceted nature, herbicide resistance has rarely been researched in a holistic manner. A novel approach combining timely resistance confirmation, investigation of resistance mechanisms, alternative control solutions and population modelling was adopted for the sustainable management of the Amaranthus palmeri weed in soybean production systems in Argentina. Here, we show that resistance to glyphosate in the studied population from Cordoba province was mainly due to a P106S target-site mutation in the 5-enolpyruvylshikimate 3-phosphate synthase (EPSPS) gene, with minor contributions from EPSPS gene duplication/overexpression. Alternative herbicides, such as fomesafen, effectively controlled the glyphosate-resistant plants. Model simulations revealed the tendency of a solo herbicidal input to primarily select for a single resistance mechanism and suggested that residual herbicides, alongside chemical diversity, were important for the sustainable use of these herbicides. We also discuss the value of an interdisciplinary approach for improved understanding of evolving weeds.

9.
Pest Manag Sci ; 76(2): 789-796, 2020 Feb.
Article in English | MEDLINE | ID: mdl-31400066

ABSTRACT

BACKGROUND: Resistance to protoporphyrinogen oxidase (PPO)-inhibiting herbicides in Amaranthus rudis from corn/soybean production systems in the USA appears to be mainly due to a codon deletion at position 210 of the target PPX2L gene. In this study, we have developed a simple and cost-effective derived Polymorphic Amplified Cleaved Sequenced (dPACS) marker for detecting this resistance-causing deletion in A. rudis and other relevant weed species. RESULTS: Ninety-six plants from 16 diverse fomesafen-sensitive and resistant A. rudis populations from Illinois and Iowa were used to establish the dPACS procedure. The assay requires forced mismatches in both the forward and reverse PCR primers and uses the restriction enzyme XcmI for the positive identification of wild type glycine residue at PPX2L codon position 210. The data from the dPACS method, using either leaf tissues or seeds as starting material, were completely correlated with direct Sanger sequencing results for samples that gave readable nucleotide peaks around codon 210 of PPX2L. Furthermore, the assay was directly transferable to all four other Amaranthus species tested, and to Ambrosia artemisiifolia using species-specific primers. CONCLUSION: The proposed assay will allow the rapid detection of the Δ210 codon deletion in the PPX2L gene and the timely development of management strategies for tackling growing resistance to PPO-inhibiting herbicides in A. rudis and other broadleaf weed species. © 2019 Society of Chemical Industry.


Subject(s)
Amaranthus , Codon , Herbicide Resistance , Herbicides , Illinois , Iowa , Protoporphyrinogen Oxidase
10.
Plants (Basel) ; 8(11)2019 Nov 16.
Article in English | MEDLINE | ID: mdl-31744154

ABSTRACT

The mechanism and expression of resistance to glyphosate at different plant growing temperatures was investigated in an Amaranthus palmeri population (VM1) from a soybean field in Vicuña Mackenna, Cordoba, Argentina. Resistance was not due to reduced glyphosate translocation to the meristem or to EPSPS duplication, as reported for most US samples. In contrast, a proline 106 to serine target-site mutation acting additively with EPSPS over-expression (1.8-fold increase) was respectively a major and minor contributor to glyphosate resistance in VM1. Resistance indices based on LD50 values generated using progenies from a cross between 52 PS106 VM1 individuals were estimated at 7.1 for homozygous SS106 and 4.3 for heterozygous PS106 compared with homozygous wild PP106 plants grown at a medium temperature of 24 °C day/18 °C night. A larger proportion of wild and mutant progenies survived a single commonly employed glyphosate rate when maintained at 30 °C day/26 °C night compared with 20 °C day/16 night in a subsequent experiment. Interestingly, the P106S mutation was not identified in any of the 920 plants analysed from 115 US populations, thereby potentially reflecting the difference in A. palmeri control practices in Argentina and USA.

11.
Int J Mol Sci ; 20(13)2019 Jun 29.
Article in English | MEDLINE | ID: mdl-31261867

ABSTRACT

Most methods developed for detecting known single nucleotide polymorphisms (SNP) and deletion-insertion polymorphisms (DIP) are dependent on sequence conservation around the SNP/DIP and are therefore not suitable for application to heterogeneous organisms. Here we describe a novel, versatile and simple PCR-RFLP procedure baptised 'derived Polymorphic Amplified Cleaved Sequence' (dPACS) for genotyping individual samples. The notable advantage of the method is that it employs a pair of primers that cover the entire fragment to be amplified except for one or few diagnostic bases around the SNP/DIP being investigated. As such, it provides greater opportunities to introduce mismatches in one or both of the 35-55 bp primers for creating a restriction site that unambiguously differentiates wild from mutant sequences following PCR-RFLP and horizontal MetaPhorTM gel electrophoresis. Selection of effective restriction enzymes and primers is aided by the newly developed dPACS 1.0 software. The highly transferable dPACS procedure is exemplified here with the positive detection (in up to 24 grass and broadleaf species tested) of wild type proline106 of 5-enolpyruvylshikimate-3-phosphate synthase and its serine, threonine and alanine variants that confer resistance to glyphosate, and serine264 and isoleucine2041 which are key target-site determinants for weed sensitivities to some photosystem II and acetyl-CoA carboxylase inhibiting herbicides, respectively.


Subject(s)
Amplified Fragment Length Polymorphism Analysis/methods , Genotyping Techniques/methods , INDEL Mutation , Polymorphism, Single Nucleotide , 3-Phosphoshikimate 1-Carboxyvinyltransferase/genetics , Amaranthus/genetics , Genome-Wide Association Study/methods , Lolium/genetics , Plant Proteins/genetics
12.
Article in English | MEDLINE | ID: mdl-29201388

ABSTRACT

BACKGROUND: Patient decision aids (PtDA) support quality decision-making. The aim of this research was to evaluate the feasibility of conducting a randomized controlled trial delivering an implantable cardioverter defibrillator (ICD)-specific PtDA to new ICD candidates and examining preliminary estimates of differences in outcomes. METHODS: Prior to recruitment, ICD candidacy was determined. Consented patients were randomized to (1) usual care or (2) PtDA intervention. Feasibility outcomes included referral and recruitment rates, successful PtDA delivery, and completion of measures. The PtDA intervention was administered prior to specialist consultation and baseline demographics, and measures of decision quality including decisional conflict (DCS), SURE test (Sure of myself, Understand information, Risk-benefit ratio, Encouragement), patient's ICD specific values, ICD knowledge, and health-related quality of life were recorded. Post-consultation, participant's DCS was repeated and decisions to proceed, decline, or defer ICD implantation were collected. Feasibility data was determined using descriptive statistics (continuous and categorical). Preliminary estimates of differences in outcomes were assessed using mean differences. Concordance between values and decision choice was assessed using logistic regression of the intervention group. RESULTS: We identified 135 eligible patients. Eighty-two consented to the trial randomizing patients to usual care (n = 41) or PtDA intervention (n = 41). Feasibility outcome results were (1) referral rate at approximately 20/month, (2) recruitment rate 61%, and (3) successful delivery of PtDA and study management. Pre-consultation, PtDA patients scored lower on the DCS scale (mean, standard deviation [SD] 27.3 (18.4) compared to usual care, 49.4 (18.6); the between-group difference in means [95% confidence interval (CI)] was - 22.1[- 30.23, - 13.97]. A difference remained post-implantation 21.2 (11.7), PtDA intervention 29.9 (13.3), and usual care - 8.7 [- 14.61, - 2.86]. SURE test results supported DCS differences. The PtDA group scored higher on the ICD-related knowledge questions, with 47.50% scoring greater than 3/5 of the knowledge questions correct, compared to 23.09% receiving usual care. The mean [SD] number of correct knowledge responses out of 5 was 3.33(1.19) in the PtDA group and 2.62 (1.16) in usual care pre-implant. Concordance between values and decision choice found a strong association between predicted and actual ICD implant status in the intervention group. CONCLUSION: Our results suggest that a future definitive trial is feasible. The ICD-specific PtDA shows promise with respect to preliminary estimates of differences in outcomes. TRIAL REGISTRATION: NCT01876173.

13.
PLoS One ; 12(6): e0180095, 2017.
Article in English | MEDLINE | ID: mdl-28662111

ABSTRACT

Amaranthus tuberculatus is a troublesome weed in corn and soybean production systems in Midwestern USA, due in part to its ability to evolve multiple resistance to key herbicides including 4-hydroxyphenylpyruvate dioxygenase (HPPD). Here we have investigated the mechanism of resistance to mesotrione, an important chemical for managing broadleaf weeds in corn, in a multiple herbicide resistant population (NEB) from Nebraska. NEB showed a 2.4-fold and 45-fold resistance increase to mesotrione compared to a standard sensitive population (SEN) in pre-emergence and post-emergence dose-response pot tests, respectively. Sequencing of the whole HPPD gene from 12 each of sensitive and resistant plants did not detect any target-site mutations that could be associated with post-emergence resistance to mesotrione in NEB. Resistance was not due to HPPD gene duplication or over-expression before or after herbicide treatment, as revealed by qPCR. Additionally, no difference in mesotrione uptake was detected between NEB and SEN. In contrast, higher levels of mesotrione metabolism via 4-hydroxylation of the dione ring were observed in NEB compared to the sensitive population. Overall, the NEB population was characterised by lower levels of parent mesotrione exported to other parts of the plant, either as a consequence of metabolism in the treated leaves and/or impaired translocation of the herbicide. This study demonstrates another case of non-target-site based resistance to an important class of herbicides in an A. tuberculatus population. The knowledge generated here will help design strategies for managing multiple herbicide resistance in this problematic weed species.


Subject(s)
Amaranthus/drug effects , Cyclohexanones/pharmacology , Herbicides/pharmacology , Plant Weeds/drug effects , Amaranthus/genetics , Amaranthus/metabolism , Biological Transport , Carbon Radioisotopes/metabolism , Gene Duplication , Genes, Plant , Nebraska , Plant Weeds/genetics , Plant Weeds/metabolism , Real-Time Polymerase Chain Reaction
14.
J Neuropathol Exp Neurol ; 75(11): 1058-1071, 2016 Nov 01.
Article in English | MEDLINE | ID: mdl-27634961

ABSTRACT

Within hours after stroke, potentially cytotoxic pro-inflammatory mediators are elevated within the brain; thus, one potential therapeutic strategy is to reduce them and skew the brain toward an anti-inflammatory state. Because interleukin-4 (IL-4) treatment induces an anti-inflammatory, "alternative-activation" state in microglia and macrophages in vitro, we tested the hypothesis that early supplementation of the brain with IL-4 can shift it toward an anti-inflammatory state and reduce damage after transient focal ischemia. Adult male rat striata were injected with endothelin-1, with or without co-injection of IL-4. Inflammation, glial responses and damage to neurons and white matter were quantified from 1 to 7 days later. At 1 day, IL-4 treatment increased striatal expression of several anti-inflammatory markers (ARG1, CCL22, CD163, PPARγ), increased phagocytic (Iba1-positive, CD68-positive) microglia/macrophages, and increased VEGF-A-positive infiltrating neutrophils in the infarcts. At 7 days, there was evidence of sustained, propagating responses. IL-4 increased CD206, CD200R1, IL-4Rα, STAT6, PPARγ, CD11b, and TLR2 expression and increased microglia/macrophages in the infarct and astrogliosis outside the infarct. Neurodegeneration and myelin damage were not reduced, however. The sustained immune and glial responses when resolution and repair processes have begun warrant further studies of IL-4 treatment regimens and long-term outcomes.

15.
J Neuroimmunol ; 267(1-2): 61-72, 2014 Feb 15.
Article in English | MEDLINE | ID: mdl-24360910

ABSTRACT

Transcriptional dysregulation is a major pathological feature of Huntington's disease (HD). The goal of this study was to understand how p65/RelA co-regulated genes, specifically those of the cytokine and endocannabinoid systems, were affected in HD. p65/RelA levels were lower in human HD tissue and R6/2 HD mice, as were the levels of the type 1 cannabinoid receptor (CB1), IL-1ß, IL-8, CCL5, GM-CSF, MIP-1ß, and TNFα, all of which may be regulated by p65/RelA. Activation of p65/RelA restored CB1 and CCL5 expression in STHdh cell models of HD. Therefore, p65/RelA activation may normalize the expression of some genes in HD.


Subject(s)
Corpus Striatum/metabolism , Cytokines/metabolism , Endocannabinoids/metabolism , Huntington Disease/pathology , NF-kappa B/metabolism , Transcription Factor RelA/metabolism , Adult , Age Factors , Aged , Amidohydrolases/genetics , Amidohydrolases/metabolism , Animals , Arachidonic Acids/pharmacology , Cannabinoids/pharmacology , Cells, Cultured , Corpus Striatum/cytology , Cytokines/genetics , Disease Models, Animal , Endocannabinoids/agonists , Endocannabinoids/antagonists & inhibitors , Enzyme Inhibitors/pharmacology , Female , Gene Expression Regulation/drug effects , Gene Expression Regulation/physiology , Humans , Huntingtin Protein , Indoles/pharmacology , Male , Mice , Mice, Inbred C57BL , Mice, Transgenic , Middle Aged , NF-kappa B/genetics , Nerve Tissue Proteins/genetics , Neurons/drug effects , Neurons/metabolism , Nuclear Proteins/genetics , Receptor, Cannabinoid, CB1/genetics , Receptor, Cannabinoid, CB1/metabolism , Transcription Factor RelA/genetics , Trinucleotide Repeats/genetics , Young Adult
16.
PLoS One ; 8(7): e69568, 2013.
Article in English | MEDLINE | ID: mdl-23936046

ABSTRACT

BACKGROUND: Knowledge of the mechanisms of herbicide resistance is important for designing long term sustainable weed management strategies. Here, we have used an integrated biology and molecular approach to investigate the mechanisms of resistance to acetyl-CoA carboxylase inhibiting herbicides in a UK black-grass population (BG2). METHODOLOGY/PRINCIPAL FINDINGS: Comparison between BG2 phenotypes using single discriminant rates of herbicides and genotypes based on ACCase gene sequencing showed that the I1781L, a novel I1781T, but not the W2027C mutations, were associated with resistance to cycloxydim. All plants were killed with clethodim and a few individuals containing the I1781L mutation were partially resistant to tepraloxydim. Whole plant dose response assays demonstrated that a single copy of the mutant T1781 allele conferred fourfold resistance levels to cycloxydim and clodinafop-propargyl. In contrast, the impact of the I1781T mutation was low (Rf = 1.6) and non-significant on pinoxaden. BG2 was also characterised by high levels of resistance, very likely non-target site based, to the two cereal selective herbicides clodinafop-propargyl and pinoxaden and not to the poorly metabolisable cyclohexanedione herbicides. Analysis of 480 plants from 40 cycloxydim resistant black grass populations from the UK using two very effective and high throughput dCAPS assays established for detecting any amino acid changes at the 1781 ACCase codon and for positively identifying the threonine residue, showed that the occurrence of the T1781 is extremely rare compared to the L1781 allele. CONCLUSION/SIGNIFICANCE: This study revealed a novel mutation at ACCase codon position 1781 and adequately assessed target site and non-target site mechanisms in conferring resistance to several ACCase herbicides in a black-grass population. It highlights that over time the level of suspected non-target site resistance to some cereal selective ACCase herbicides have in some instances surpassed that of target site resistance, including the one endowed by the most commonly encountered I1781L mutation.


Subject(s)
Acetyl-CoA Carboxylase/genetics , Drug Resistance/genetics , Herbicides/pharmacology , Mutation , Plant Proteins/genetics , Plant Weeds/drug effects , Plant Weeds/genetics , Acetyl-CoA Carboxylase/metabolism , Alleles , Genotype , Phenotype , Plant Proteins/metabolism , Plant Weeds/enzymology , Weed Control
17.
Proc Natl Acad Sci U S A ; 110(15): 5812-7, 2013 Apr 09.
Article in English | MEDLINE | ID: mdl-23530204

ABSTRACT

Multiple-herbicide resistance (MHR) in black-grass (Alopecurus myosuroides) and annual rye-grass (Lolium rigidum) is a global problem leading to a loss of chemical weed control in cereal crops. Although poorly understood, in common with multiple-drug resistance (MDR) in tumors, MHR is associated with an enhanced ability to detoxify xenobiotics. In humans, MDR is linked to the overexpression of a pi class glutathione transferase (GSTP1), which has both detoxification and signaling functions in promoting drug resistance. In both annual rye-grass and black-grass, MHR was also associated with the increased expression of an evolutionarily distinct plant phi (F) GSTF1 that had a restricted ability to detoxify herbicides. When the black-grass A. myosuroides (Am) AmGSTF1 was expressed in Arabidopsis thaliana, the transgenic plants acquired resistance to multiple herbicides and showed similar changes in their secondary, xenobiotic, and antioxidant metabolism to those determined in MHR weeds. Transcriptome array experiments showed that these changes in biochemistry were not due to changes in gene expression. Rather, AmGSTF1 exerted a direct regulatory control on metabolism that led to an accumulation of protective flavonoids. Further evidence for a key role for this protein in MHR was obtained by showing that the GSTP1- and MDR-inhibiting pharmacophore 4-chloro-7-nitro-benzoxadiazole was also active toward AmGSTF1 and helped restore herbicide control in MHR black-grass. These studies demonstrate a central role for specific GSTFs in MHR in weeds that has parallels with similar roles for unrelated GSTs in MDR in humans and shows their potential as targets for chemical intervention in resistant weed management.


Subject(s)
Glutathione Transferase/physiology , Herbicide Resistance/genetics , Herbicides/pharmacology , Plant Weeds/enzymology , Poaceae/enzymology , Arabidopsis/genetics , Gene Expression Regulation, Plant , Genes, Plant , Glutathione Transferase/genetics , Oligonucleotide Array Sequence Analysis , Phenotype , Plant Weeds/genetics , Plants, Genetically Modified , Poaceae/genetics , Transgenes
18.
PLoS One ; 8(2): e58012, 2013.
Article in English | MEDLINE | ID: mdl-23469130

ABSTRACT

BACKGROUND: Acetyl-CoA carboxylase (ACCase) inhibiting herbicides are important products for the post-emergence control of grass weed species in small grain cereal crops. However, the appearance of resistance to ACCase herbicides over time has resulted in limited options for effective weed control of key species such as Lolium spp. In this study, we have used an integrated biological and molecular biology approach to investigate the mechanism of resistance to ACCase herbicides in a Lolium multiflorum Lam. from the UK (UK21). METHODOLOGY/PRINCIPAL FINDINGS: The study revealed a novel tryptophan to serine mutation at ACCase codon position 1999 impacting on ACCase inhibiting herbicides to varying degrees. The W1999S mutation confers dominant resistance to pinoxaden and partially recessive resistance to cycloxydim and sethoxydim. On the other hand, plants containing the W1999S mutation were sensitive to clethodim and tepraloxydim. Additionally population UK21 is characterised by other resistance mechanisms, very likely non non-target site based, affecting several aryloxyphenoxyproprionate (FOP) herbicides but not the practical field rate of pinoxaden. The positive identification of wild type tryptophan and mutant serine alleles at ACCase position 1999 could be readily achieved with an original DNA based derived cleaved amplified polymorphic sequence (dCAPS) assay that uses the same PCR product but two different enzymes for positively identifying the wild type tryptophan and mutant serine alleles identified here. CONCLUSION/SIGNIFICANCE: This paper highlights intrinsic differences between ACCase inhibiting herbicides that could be exploited for controlling ryegrass populations such as UK21 characterised by compound-specific target site and non-target site resistance.


Subject(s)
Acetyl-CoA Carboxylase/antagonists & inhibitors , Acetyl-CoA Carboxylase/genetics , Drug Resistance/genetics , Enzyme Inhibitors/pharmacology , Herbicides/pharmacology , Lolium/drug effects , Mutation , Base Sequence , DNA, Plant/genetics , Genetic Markers/genetics , Heterocyclic Compounds, 2-Ring/pharmacology , Lolium/enzymology , Lolium/genetics , United Kingdom
19.
N Z Med J ; 125(1360): 57-65, 2012 Aug 24.
Article in English | MEDLINE | ID: mdl-22932655

ABSTRACT

Gynaecological cancer services in New Zealand have followed an evolutionary process rather than being centrally organised according to evidence on best practice. A report was recently commissioned by the Ministry of Health to review gynaecological cancer services and to provide guidance on the most efficient and effective way to delivery high quality, equitable care for women diagnosed with gynaecological cancers. It is apparent the sustainability of current services is compromised by disparities in access to evidence-based multidisciplinary care, significant workforce shortages and a lack of standardised formal referral protocols. Key recommendations of the report include the establishment of an overarching national gynaecological cancer steering group and ultimately a four centre hub and spoke model of care provision.


Subject(s)
Genital Neoplasms, Female/epidemiology , Genital Neoplasms, Female/therapy , Needs Assessment , Obstetrics and Gynecology Department, Hospital/organization & administration , Oncology Service, Hospital/organization & administration , Women's Health Services/organization & administration , Female , Gynecology , Humans , Medical Oncology , New Zealand/epidemiology , Nurses/supply & distribution , Patient Care Team , Physicians/supply & distribution , Referral and Consultation , Workforce
20.
PLoS One ; 7(6): e39759, 2012.
Article in English | MEDLINE | ID: mdl-22768118

ABSTRACT

BACKGROUND: The design of sustainable weed management strategies requires a good understanding of the mechanisms by which weeds evolve resistance to herbicides. Here we have conducted a study on the mechanism of resistance to ACCase inhibiting herbicides in a Lolium multiflorum population (RG3) from the UK. METHODOLOGY/PRINCIPAL FINDINGS: Analysis of plant phenotypes and genotypes showed that all the RG3 plants (72%) that contained the cysteine to arginine mutation at ACCase codon position 2088 were resistant to ACCase inhibiting herbicides. Whole plant dose response tests on predetermined wild and mutant 2088 genotypes from RG3 and a standard sensitive population indicated that the C2088R mutation is the only factor conferring resistance to all ten ACCase herbicides tested. The associated resistance indices ranged from 13 for clethodim to over 358 for diclofop-methyl. Clethodim, the most potent herbicide was significantly affected even when applied on small mutant plants at the peri-emergence and one leaf stages. CONCLUSION/SIGNIFICANCE: This study establishes the clear and unambiguous importance of the C2088R target site mutation in conferring broad resistance to ten commonly used ACCase inhibiting herbicides. It also demonstrates that low levels "creeping", multigenic, non target site resistance, is not always selected before single gene target site resistance appears in grass weed populations subjected to herbicide selection pressure.


Subject(s)
Acetyl-CoA Carboxylase/antagonists & inhibitors , Arginine/genetics , Cysteine/genetics , Herbicide Resistance/genetics , Herbicides/pharmacology , Lolium/enzymology , Mutation/genetics , Acetyl-CoA Carboxylase/genetics , Cyclohexanones , Genes, Plant/genetics , Genetics, Population , Genotyping Techniques , Heterocyclic Compounds, 2-Ring/pharmacology , Lolium/drug effects , Lolium/genetics , Plant Leaves/drug effects , Plant Leaves/growth & development , Propionates/pharmacology , Pyridines/pharmacology , Reproducibility of Results , Seeds/drug effects , Selection, Genetic
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