Environmental Conditions Influence Induction of Key ABC-Transporter Genes Affecting Glyphosate Resistance Mechanism in Conyza canadensis

Prorocentrum lima is a typical benthic toxic dinoflagellate, which can produce phycotoxins such as okadaic acid (OA). In this study, we identified three ABC transporter genes (ABCB1, ABCC1 and ABCG2) and characterized their expression patterns, as well as OA production under different environmental conditions in P. lima. We found that the three ABC transporters all showed high identity with related ABC proteins from other species, and contained classical features of ABC transport proteins. Among them, ABCG2 was a half size transporter. The three ABC transporter genes displayed various expression profiles under different conditions. The high concentration of Cu2+ could up-regulate ABCB1, ABCC1 and ABCG2 transcripts in P. lima, suggesting the potential defensive role of ABC transporters against metal ions in surrounding waters. Cu2+, in some concentration, could induce OA production; meanwhile, tributyltin inhibited OA accumulation. The grazer Artemia salina could induce OA production, and P. lima displayed some toxicity to the grazer, indicating the possibility of OA as an anti-grazing chemical. Collectively, our results revealed intriguing data about OA production and the expression patterns of three ABC transporter genes. However, we could not find any significant correlation between OA production and expression pattern of the three ABC transporters in P. lima. Our results might provide new molecular insights on the defensive responses of P. lima to the surrounding environment.

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Biochemical and Rapid Molecular Analyses to Identify Glyphosate Resistance in Lolium spp.

Agronomy ◽

10.3390/agronomy12010040 ◽

2021 ◽

Vol 12 (1) ◽

pp. 40

Author(s):

Maria Gerakari ◽

Nikolina Cheimona ◽

Eleni Tani ◽

Ilias Travlos ◽

Demosthenis Chachalis ◽

...

Keyword(s):

Abc Transporter ◽

Dose Response ◽

Shikimic Acid ◽

Glyphosate Resistance ◽

Winter Cereal ◽

Transcript Levels ◽

Molecular Analyses ◽

Time Points ◽

Epsps Gene ◽

Abc Transporter Genes

Lolium spp. are troublesome weeds mainly found in winter cereal crops worldwide, including Europe. In recent years resistant mechanisms have been evolved to several important herbicides. In this study we investigated the mechanisms responsible for conferring glyphosate resistance in some Lolium spp. populations. A holistic approach was used, based on dose-response experiments, determination of shikimic acid concentration in plant leaf tissue, as well as molecular analyses. More specifically, in three Lolium spp. populations the existence of a mutation in the Pro-106 codon of the 5-enolpyruvylshikimate-3 phosphate synthase (EPSPS) gene was investigated as well as the relative transcript levels of four ABC-transporter genes were monitored at three time points after glyphosate application. The results demonstrated that glyphosate resistance is a multifactor phenomenon. Relative transcript levels of the ABC-transporter genes were abundant at very early time points after glyphosate treatments. Dose-response experiments and shikimate analyses were in accordance with the findings of the quantitative PCR (qPCR) analyses. We suggest that relative expression ratio of ABC-transporter genes can be a useful tool to rapidly identify Lolium spp. populations resistant to glyphosate.

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Repeated Ivermectin Treatment Induces Ivermectin Resistance in Strongyloides ratti by Upregulating the Expression of ATP-Binding Cassette Transporter Genes

American Journal of Tropical Medicine and Hygiene ◽

10.4269/ajtmh.21-0377 ◽

2021 ◽

Author(s):

Chatchawan Sengthong ◽

Manachai Yingklang ◽

Kitti Intuyod ◽

Ornuma Haonon ◽

Porntip Pinlaor ◽

...

Keyword(s):

Larval Development ◽

Abc Transporter ◽

Resistance Mechanism ◽

Atp Binding ◽

Expression Levels ◽

Atp Binding Cassette Transporter ◽

Sensitivity Tests ◽

Abc Transporter Genes ◽

Atp Binding Cassette

Ivermectin (IVM) is a widely used anthelmintic. However, with widespread use comes the risk of the emergence of IVM resistance, particularly in strongyloidiasis. Adenosine triphosphate (ATP)-binding cassette (ABC) transporter genes play an important role in the IVM-resistance mechanism. Here, we aimed to establish an animal experimental model of IVM resistance by frequent treatment of Strongyloides ratti with subtherapeutic doses of IVM, resistance being evaluated by the expression levels of ABC transporter genes. Rats infected with S. ratti were placed in experimental groups as follows: 1) untreated control (control); 2) treated with the mutagen ethyl methanesulfonate (EMS); 3) injected with 100 µg/kg body weight of IVM (IVM); 4) treated with a combination of EMS and IVM (IVM+EMS). Parasites were evaluated after four generations. Extent of IVM resistance was assessed using IVM sensitivity, larval development, and expression of ABC genes. By the F4 generation, S. ratti in the IVM group exhibited significantly higher levels of IVM resistance than did other groups according to in vitro drug-sensitivity tests and inhibition of larval development (IC50 = 36.60 ng/mL; 95% CI: 31.6, 42.01). Expression levels of ABC isoform genes (ABCA, ABCF, and ABCG) were statistically significantly higher in the IVM-resistant line compared with the susceptible line. In conclusion, IVM subtherapeutic doses induced IVM resistance in S. ratti by the F4 generation with corresponding upregulation of some ABC isoform genes. The study provides a model for inducing and assessing drug resistance in Strongyloides.

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Environmental cues affecting horseweed (Conyza canadensis) growth type and their sensitivity to glyphosate

Weed Science ◽

10.1017/wsc.2021.27 ◽

2021 ◽

pp. 1-35

Author(s):

John A. Schramski ◽

Christy L. Sprague ◽

Eric L. Patterson

Keyword(s):

Soil Moisture ◽

Glyphosate Resistance ◽

Single Parent ◽

Environmental Cues ◽

Conyza Canadensis ◽

Growth Type ◽

Susceptible Population ◽

Water Imbibition ◽

Growth Types ◽

Winter Annual

Abstract Horseweed [Conyza canadensis (L.) Cronquist] is a facultative winter annual weed that can emerge from March to November in Michigan. Fall emerging C. canadensis overwinters as a rosette, while spring emerging C. canadensis skips the rosette stage and immediately grows upright upon emergence. In Michigan, primary emergence recently shifted from fall to spring/summer and therefore from a rosette to an upright growth type. Growth chamber experiments were conducted to determine 1) whether both C. canadensis growth types could originate from a single parent and 2) if common environmental cues can influence growth type. Variations in temperature, photoperiod, competition, shading, and soil moisture only resulted in the rosette growth type in four C. canadensis populations originating from seed collected from a single parent of the upright growth type. However, a vernalization period of four weeks following water imbibition, but prior to germination, resulted in the upright growth type. Dose-response experiments were conducted to determine whether glyphosate sensitivity differed between C. canadensis growth types generated from a single parent of the upright growth type. Upright type C. canadensis from known glyphosate-resistant populations ISB-18 and MSU-18 were four and three-fold less sensitive to glyphosate than their rosette siblings, respectively. Interestingly, differences in glyphosate sensitivity was not observed between growth types from the susceptible population. These results suggest that while C. canadensis populations shift from winter to summer annual lifecycles, concurrent increases in glyphosate resistance could occur.

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Role of absorption and translocation in the mechanism of glyphosate resistance in horseweed (Conyza canadensis)

Weed Science ◽

10.1614/ws-04-102r ◽

2005 ◽

Vol 53 (1) ◽

pp. 84-89 ◽

Cited By ~ 100

Author(s):

Clifford H. Koger ◽

Krishna N. Reddy

Keyword(s):

Glyphosate Resistance ◽

Conyza Canadensis

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5030 POSTER Expression Profile of ABC Transporter Genes in Breast Carcinoma

European Journal of Cancer ◽

10.1016/s0959-8049(11)71472-1 ◽

2011 ◽

Vol 47 ◽

pp. S339-S340

Author(s):

V. Hlavac ◽

R. Vaclavikova ◽

M. Ehrlichova ◽

I. Hlavata ◽

V. Pecha ◽

...

Keyword(s):

Breast Carcinoma ◽

Abc Transporter ◽

Expression Profile ◽

Abc Transporter Genes

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Functional Genomics Analysis of Horseweed (Conyza canadensis) with Special Reference to the Evolution of Non–Target-Site Glyphosate Resistance

Weed Science ◽

10.1614/ws-d-09-00037.1 ◽

2010 ◽

Vol 58 (2) ◽

pp. 109-117 ◽

Cited By ~ 48

Author(s):

Joshua S. Yuan ◽

Laura L. G. Abercrombie ◽

Yongwei Cao ◽

Matthew D. Halfhill ◽

Xin Zhou ◽

...

Keyword(s):

Functional Genomics ◽

Molecular Mechanisms ◽

Glyphosate Resistance ◽

Resistance Mechanisms ◽

Target Site ◽

Environmentally Benign ◽

Conyza Canadensis ◽

Target Site Resistance ◽

Weedy Species ◽

Heterologous Microarray

The evolution of glyphosate resistance in weedy species places an environmentally benign herbicide in peril. The first report of a dicot plant with evolved glyphosate resistance was horseweed, which occurred in 2001. Since then, several species have evolved glyphosate resistance and genomic information about nontarget resistance mechanisms in any of them ranges from none to little. Here, we report a study combining iGentifier transcriptome analysis, cDNA sequencing, and a heterologous microarray analysis to explore potential molecular and transcriptomic mechanisms of nontarget glyphosate resistance of horseweed. The results indicate that similar molecular mechanisms might exist for nontarget herbicide resistance across multiple resistant plants from different locations, even though resistance among these resistant plants likely evolved independently and available evidence suggests resistance has evolved at least four separate times. In addition, both the microarray and sequence analyses identified non–target-site resistance candidate genes for follow-on functional genomics analysis.

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Distribution and validation of genotypic and phenotypic glyphosate and PPO-nhibitor resistance in Palmer amaranth (Amaranthus palmeri) from southwestern Nebraska

Weed Technology ◽

10.1017/wet.2020.74 ◽

2020 ◽

pp. 1-12 ◽

Cited By ~ 1

Author(s):

Maxwel C Oliveira ◽

Darci A Giacomini ◽

Nikola Arsenijevic ◽

Gustavo Vieira ◽

Patrick J Tranel ◽

...

Keyword(s):

Cluster Analysis ◽

Gene Amplification ◽

Cropping Systems ◽

Resistance Mechanism ◽

Geographic Area ◽

Glyphosate Resistance ◽

Resistance Mechanisms ◽

Palmer Amaranth ◽

Resistance Evolution ◽

Inhibitor Resistance

Abstract Failure to control Palmer amaranth with glyphosate and protoporphyrinogen IX oxidase (PPO)-inhibitor herbicides was reported across southwestern Nebraska in 2017. The objectives of this study were to 1) confirm and 2) validate glyphosate and PPO-inhibitor (fomesafen and lactofen) resistance in 51 Palmer amaranth accessions from southwestern Nebraska using genotypic and whole-plant phenotypic assay correlations and cluster analysis, and 3) determine which agronomic practices might be influencing glyphosate resistance in Palmer amaranth accessions in that location. Based on genotypic assay, 88% of 51 accessions contained at least one individual with amplification (>2 copies) of the 5-enolypyruvyl-shikimate-3-phosphate synthase (EPSPS) gene, which confers glyphosate resistance; and/or a mutation in the PPX2 gene, either ΔG210 or R128G, which endows PPO-inhibitor resistance in Palmer amaranth. Cluster analysis and high correlation (0.83) between genotypic and phenotypic assays demonstrated that EPSPS gene amplification is the main glyphosate resistance mechanism in Palmer amaranth accessions from southwestern Nebraska. In contrast, there was poor association between genotypic and phenotypic responses for PPO-inhibitor resistance, which was attributed to segregation for PPO-inhibitor resistance within these accessions and/or the methodology that was adopted herein. Genotypic assays can expedite the process of confirming known glyphosate and PPO-inhibitor resistance mechanisms in Palmer amaranth from southwestern Nebraska and other locations. Phenotypic assays are also a robust method for confirming glyphosate resistance but not necessarily PPO-inhibitor resistance in Palmer amaranth. Moreover, random forest analysis of glyphosate resistance in Palmer amaranth indicated that EPSPS gene amplification, county, and current and previous crops are the main factors influencing glyphosate resistance within that geographic area. Most glyphosate-susceptible Palmer amaranth accessions were found in a few counties in areas with high crop diversity. Results presented here confirm the spread of glyphosate resistance and PPO-inhibitor resistance in Palmer amaranth accessions from southwestern Nebraska and demonstrate that less diverse cropping systems are an important driver of herbicide resistance evolution in Palmer amaranth.

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