A Multistate Study of the Association Between Glyphosate Resistance and EPSPS Gene Amplification in Waterhemp (Amaranthus tuberculatus)

Waterhemp is an increasingly problematic weed in the U.S. Midwest, having now evolved resistances to herbicides from six different site-of-action groups. Glyphosate-resistant waterhemp in the Midwest is especially concerning given the economic importance of glyphosate in corn and soybean production. Amplification of the target-site gene, 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) was found to be the mechanism of glyphosate resistance in Palmer amaranth, a species closely related to waterhemp. Here, the relationship between glyphosate resistance and EPSPS gene amplification in waterhemp was investigated. Glyphosate dose response studies were performed at field sites with glyphosate-resistant waterhemp in Illinois, Kansas, Kentucky, Missouri, and Nebraska, and relative EPSPS copy number of survivors was determined via quantitative real-time polymerase chain reaction (qPCR). Waterhemp control increased with increasing glyphosate rate at all locations, but no population was completely controlled even at the highest rate (3,360 g ae ha−1). EPSPS gene amplification was present in plants from four of five locations (Illinois, Kansas, Missouri, and Nebraska) and the proportion of plants with elevated copy number was generally higher in survivors from glyphosate-treated plots than in plants from the untreated control plots. Copy number magnitude varied by site, but an overall trend of increasing copy number with increasing rate was observed in populations with gene amplification, suggesting that waterhemp plants with more EPSPS copies are more resistant. Survivors from the Kentucky population did not have elevated EPSPS copy number. Instead, resistance in this population was attributed to the EPSPS Pro106Ser mutation. Results herein show a quantitative relationship between glyphosate resistance and EPSPS gene amplification in some waterhemp populations, while highlighting that other mechanisms also confer glyphosate resistance in waterhemp.

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Fitness Cost Associated With Enhanced EPSPS Gene Copy Number and Glyphosate Resistance in an Amaranthus tuberculatus Population

Frontiers in Plant Science ◽

10.3389/fpls.2021.651381 ◽

2021 ◽

Vol 12 ◽

Author(s):

Helen M. Cockerton ◽

Shiv S. Kaundun ◽

Lieselot Nguyen ◽

Sarah Jane Hutchings ◽

Richard P. Dale ◽

...

Keyword(s):

Interspecific Competition ◽

Gene Amplification ◽

Copy Number ◽

Gene Copy Number ◽

Glyphosate Resistance ◽

Gene Copy ◽

Competitive Response ◽

Trade Off ◽

Epsps Gene ◽

Amaranthus Tuberculatus

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.

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EPSPS Gene Amplification is Present in the Majority of Glyphosate-Resistant Illinois Waterhemp (Amaranthus tuberculatus) Populations

Weed Technology ◽

10.1614/wt-d-14-00064.1 ◽

2015 ◽

Vol 29 (1) ◽

pp. 48-55 ◽

Cited By ~ 31

Author(s):

Laura A. Chatham ◽

Chenxi Wu ◽

Chance W. Riggins ◽

Aaron G. Hager ◽

Bryan G. Young ◽

...

Keyword(s):

Gene Amplification ◽

High Throughput Screening ◽

Glyphosate Resistance ◽

The State ◽

Molecular Test ◽

Molecular Assay ◽

Epsps Gene ◽

Whole Plant ◽

Alternative Means ◽

Amaranthus Tuberculatus

With the frequency of glyphosate-resistant waterhemp increasing throughout the Midwest, the identification of resistant populations has become important for managing this species. However, high-throughput screening for glyphosate resistance in the greenhouse is tedious and inefficient. Research was conducted to document the occurrence of glyphosate-resistant waterhemp throughout the state of Illinois, and to determine whether a molecular assay for 5-enolypyruvyl-shikimate-3-phosphate synthase (EPSPS) gene amplification can be used as an alternative means to detect resistant populations. Populations throughout the state of Illinois were collected in 2010 and screened for glyphosate resistance using a whole-plant assay in a greenhouse, and survivors were examined for EPSPS gene amplification. Of 80 populations investigated, 22 were glyphosate resistant based on the greenhouse screen, and gene amplification was identified in 20 (91%) of the resistant populations. Although there are multiple mechanisms for glyphosate resistance in waterhemp, a molecular test for EPSPS gene amplification provides a rapid alternative for identification of glyphosate resistance in most populations.

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VERIFICATION OF THE MECHANISM OF GLYPHOSATE RESISTANCE IN ITALIAN RYEGRASS BIOTYPES

Planta Daninha ◽

10.1590/s0100-83582016340300017 ◽

2016 ◽

Vol 34 (3) ◽

pp. 565-573 ◽

Cited By ~ 3

Author(s):

L. VARGAS ◽

Q. RUCHEL ◽

D. AGOSTINETTO ◽

F.P. LAMEGO ◽

A.C. LANGARO ◽

...

Keyword(s):

Point Mutation ◽

Weed Control ◽

Glyphosate Resistance ◽

Italian Ryegrass ◽

Piperonyl Butoxide ◽

P450 Monooxygenase ◽

Epsps Gene ◽

Site Of Action

ABSTRACT The intense use of glyphosate for weed control led to the emergence of several cases of resistance to this herbicide. Weeds can survive the application of herbicides due to several factors, which may or may not be related to the herbicide site of action. The objectives of this study were to quantify the accumulation of shikimate in ryegrass biotypes in response to glyphosate application; investigate possible mutations on the EPSPs gene in susceptible and resistant biotypes; and evaluate the response of ryegrass biotypes to the application of glyphosate after treatment with a metabolism inhibitor of cyt P450 monooxygenase. The seeds of ryegrass biotypes with suspected resistance came from the municipality of São Valentim, RS (SVA 1 and SVA 4) and Passo Fundo, RS (PFU 5) and the seeds of the susceptible biotype (SVA 2), from São Valentim. The results demonstrated that, SVA biotype 2 accumulated more shikimate than any of the resistant biotypes, regardless of the herbicide dose used. The EPSPs gene showed no point mutation previously associated with the resistance to glyphosate, and the evaluated biotypes show no metabolism of glyphosate by the cyt P450 complex concerning inhibition by piperonyl butoxide (PBO) and malathion.

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No fitness cost of glyphosate resistance endowed by massive EPSPS gene amplification in Amaranthus palmeri

Planta ◽

10.1007/s00425-013-2022-x ◽

2014 ◽

Vol 239 (4) ◽

pp. 793-801 ◽

Cited By ~ 64

Author(s):

Martin M. Vila-Aiub ◽

Sou S. Goh ◽

Todd A. Gaines ◽

Heping Han ◽

Roberto Busi ◽

...

Keyword(s):

Gene Amplification ◽

Glyphosate Resistance ◽

Fitness Cost ◽

Amaranthus Palmeri ◽

Epsps Gene

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Prediction of glyphosate resistance level based on EPSPS gene copy number in Kochia scoparia

10.1101/047878 ◽

2016 ◽

Author(s):

Todd A. Gaines ◽

Abigail L. Barker ◽

Eric L. Patterson ◽

Philip Westra ◽

Eric P. Westra ◽

...

Keyword(s):

Gene Duplication ◽

Empirical Model ◽

Copy Number ◽

Gene Copy Number ◽

Glyphosate Resistance ◽

Gene Copy ◽

Kochia Scoparia ◽

Resistance Level ◽

Epsps Gene ◽

Fallow Systems

AbstractGlyphosate-resistant (GR) Kochia scoparia has evolved in dryland chemical fallow systems throughout North America and the mechanism involves 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) gene duplication. Sugarbeet fields in four states were surveyed for K. scoparia in 2013 and tested for glyphosate-resistance level and EPSPS gene copy number. Glyphosate resistance was confirmed in K. scoparia populations collected from sugarbeet fields in Colorado, Wyoming, and Nebraska. The GR samples all had increased EPSPS gene copy number, with median population values up to 11. An empirical model was developed to estimate the level of glyphosate-resistance in K. scoparia based on EPSPS gene copy number. The results suggested that glyphosate susceptibility can be accurately diagnosed using EPSPS gene copy number, and further increases in EPSPS gene copy number could increase resistance levels up to 8-fold relative to susceptible K. scoparia. These trends suggest that continued glyphosate selection pressure is selecting for higher EPSPS copy number and higher resistance levels in K. scoparia. By including multiple K. scoparia samples lacking EPSPS gene duplication, our empirical model provides a more realistic estimate of fold-resistance due to EPSPS gene copy number compared to methods that do not account for normal variation of herbicide response in susceptible biotypes.

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NOVEL AGING BIOMARKERS IN THE HRS

Innovation in Aging ◽

10.1093/geroni/igz038.1611 ◽

2019 ◽

Vol 3 (Supplement_1) ◽

pp. S431-S431

Author(s):

Eileen Crimmins

Keyword(s):

Flow Cytometry ◽

Social Factors ◽

Early Life ◽

Copy Number ◽

Individual Cell ◽

Chain Reaction ◽

Mitochondrial Dna Copy Number ◽

Race Ethnicity ◽

Polymerase Chain ◽

The Relationship

Abstract In addition to the broad panel of aging related biomarkers available in HRS, we will describe measurement of novel aging biomarkers such as telomere length and mitochondrial DNA copy number in 4000 HRS participants. Both these biomarkers were measured in DNA obtained from whole unsorted blood using quantitative real time polymerase chain reaction (PCR) and were adjusted for individual cell composition measured from flow cytometry. We will describe the relationship between these two biomarkers and other measures of biological age available in HRS. Differences in these two novel aging biomarker by socioeconomic status, race/ethnicity, and exposure to early life hardships will be presented to clarify the value of the data to further unravel how social factors get under the skin to affect the process of aging.

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EPSPS Gene Copy Number and Whole-Plant Glyphosate Resistance Level in Kochia scoparia

PLoS ONE ◽

10.1371/journal.pone.0168295 ◽

2016 ◽

Vol 11 (12) ◽

pp. e0168295 ◽

Cited By ~ 18

Author(s):

Todd A. Gaines ◽

Abigail L. Barker ◽

Eric L. Patterson ◽

Philip Westra ◽

Eric P. Westra ◽

...

Keyword(s):

Copy Number ◽

Gene Copy Number ◽

Glyphosate Resistance ◽

Gene Copy ◽

Kochia Scoparia ◽

Resistance Level ◽

Epsps Gene ◽

Whole Plant

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Analysis of the mitochondrial 4977 bp deletion in patients with hepatocellular carcinoma

Balkan Journal of Medical Genetics ◽

10.1515/bjmg-2017-0006 ◽

2017 ◽

Vol 20 (1) ◽

pp. 81-86 ◽

Cited By ~ 9

Author(s):

ZS Guo ◽

CL Jin ◽

ZJ Yao ◽

YM Wang ◽

BT Xu

Keyword(s):

Hepatocellular Carcinoma ◽

Copy Number ◽

Pcr Amplification ◽

Mtdna Copy Number ◽

Nested Polymerase Chain Reaction ◽

Mutational Screening ◽

Frequent Mutations ◽

Polymerase Chain ◽

The Relationship ◽

Mt Genome

Abstract Mutations in the mitochondrial (mt) genome that result in mt dysfunction, have long been proposed to play important roles in the pathogenesis of hepatocellular carcinoma (HCC). Among these, the common mtDNA 4977 bp deletion is one of the most frequent mutations observed in various cancers. To understand the relationship between the mtDNA 4977 bp deletion and HCC, we performed mutational screening for the presence of this deletion in 105 HCC patients and 69 unrelated healthy subjects. After nested-polymerase chain reaction (nested-PCR) amplification, we found that there were 10 patients carrying the mtDNA 4977 bp deletion, and this deletion was absent in control subjects. Moreover, HCC patients carrying this deletion showed a marked increase in reactive oxygen species (ROS) level and mtDNA copy number when compared with the healthy controls. Taken together, our data indicated that the mtDNA 4977 bp deletion may play important role in the carcinogenesis of HCC, possibly via the alternation of mtDNA copy number and oxidative stress.

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No Impact of Increased EPSPS Gene Copy Number on Growth and Fecundity of Glyphosate-Resistant Kochia (Bassia scoparia)

Weed Science ◽

10.1017/wsc.2018.82 ◽

2018 ◽

Vol 67 (1) ◽

pp. 22-28 ◽

Cited By ~ 1

Author(s):

O. Adewale Osipitan ◽

J. Anita Dille

Keyword(s):

Weed Management ◽

Copy Number ◽

Plant Biomass ◽

Management Strategies ◽

Gene Copy Number ◽

Glyphosate Resistance ◽

Gene Copy ◽

Competitive Response ◽

Epsps Gene

AbstractThe level of glyphosate resistance in kochia [Bassia scoparia(L.) A. J. Scott] was reported to be due to an increase in 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) gene copy number. A field study was conducted near Manhattan, KS, in 2014 and 2015 to evaluate the relationship between EPSPS gene copy number and growth and fecundity variables ofB. scopariaindividuals within suspected glyphosate-resistant (GR) populations from western Kansas. Initial assays of EPSPS gene copy and in vivo shikimate accumulation showed thatB. scopariapopulations from Finney (FN-R), Scott (SC-R), and Thomas (TH-R) counties were segregating for glyphosate resistance, with some individuals still being glyphosate susceptible (GS). A target-neighborhood competition approach was used to evaluate the competitive response of individual target plants with relatively low (classified as GS) and high (classified as GR) EPSPS gene copy number within the populations. There was no relationship observed between EPSPS gene copy number and vegetative or fecundity variables. There was no differential competitive response of target plant biomass to increasing neighbor density between individuals with low and high EPSPS gene copy number within each population. Lack of associated vegetative growth and fecundity cost to the increased EPSPS gene copy in the GRB. scopariaplants suggests that the plants are likely to persist in field populations, except when effective weed management strategies are adopted that would prevent their growth and seed production.

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MiR-125a-5p Alleviates Dysfunction and Inflammation of Pentylenetetrazol- induced Epilepsy Through Targeting Calmodulin-dependent Protein Kinase IV (CAMK4)

Current Neurovascular Research ◽

10.2174/1567202616666190906125444 ◽

2019 ◽

Vol 16 (4) ◽

pp. 365-372 ◽

Cited By ~ 4

Author(s):

Qishuai Liu ◽

Li Wang ◽

Guizhen Yan ◽

Weifa Zhang ◽

Zhigang Huan ◽

...

Keyword(s):

Protein Kinase ◽

Target Gene ◽

Luciferase Assay ◽

Enzyme Linked Immunosorbent Assay ◽

Inflammatory Factor ◽

Dependent Protein Kinase ◽

Expression Levels ◽

Dependent Protein ◽

Polymerase Chain ◽

The Relationship

Background: MicroRNAs (miRNA) are known to play a key role in the etiology and treatment of epilepsy through controlling the expression of gene. However, miR-125a-5p in the epilepsy is little known. Epilepsy in rat models was induced by Pentylenetetrazol (PTZ) and miR- 125a-5p profiles in the hippocampus were investigated in our experiment. Also, the relationship between miR-125a-5p and calmodulin-dependent protein kinase IV (CAMK4) was identified and the related mechanism was also illustrated. Methods: The miR-125a-5p mRNA expression levels were evaluated by quantitative real time polymerase chain reaction (qRT-PCR). Western Blot (WB) was used to analyze the CAMK4 protein expression levels. Seizure score, latency and duration were determined based on a Racine scale. The enzyme-linked immunosorbent assay (ELISA) was used to analyze the inflammatory factor expression. The relationship between miR-125a-5p and CAMK4 was detected through dual luciferase assay. Results: Downregulation of miR-125a-5p was observed in the hippocampus of PTZ-induced epilepsy rats. The overexpression of miR-125a-5p attenuated seizure and decreased inflammatory factor level in the hippocampus of PTZ-induced rats. The miR-125a-5p alleviated epileptic seizure and inflammation in PTZ-induced rats by suppressing its target gene, CAMK4. Conclusion: miR-125a-5p may represent a novel therapeutic treatment for PTZ-induced epilepsy by preventing the activation of CAMK4.

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