Microbioassays to Determine the Activity of Membrane Disrupter Herbicides

Molin, William T.; Khan, Rehana A.

doi:10.1006/pest.1995.1065

Cited by 9 publications

(6 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The plate was sealed with micropore tape and placed on a bench under light for 24 h. The plate was moved to a -80 °C freezer to stop the reaction. After two freeze-thaw cycles, ammonia content was measured in a spectrophotometer (Pharma Spec UV-1700, Shimadzu, Columbia, MD) at 630 nm using a modified method by Molin and Khan [ 41 ]. Leaf discs from S plants were expected to have higher ammonia content than those from T plants.…”

Section: Methodsmentioning

confidence: 99%

RNA-Seq transcriptome analysis of Amaranthus palmeri with differential tolerance to glufosinate herbicide

Salas-Perez

Saski²,

Noorai³

et al. 2018

PLoS ONE

View full text Add to dashboard Cite

Amaranthus palmeri (Amaranthaceae) is a noxious weed in several agroecosystems and in some cases seriously threatens the sustainability of crop production in North America. Glyphosate-resistant Amaranthus species are widespread, prompting the use of alternatives to glyphosate such as glufosinate, in conjunction with glufosinate-resistant crop cultivars, to help control glyphosate-resistant weeds. An experiment was conducted to analyze the transcriptome of A. palmeri plants that survived exposure to 0.55 kg ha-1 glufosinate. Since there was no record of glufosinate use at the collection site, survival of plants within the population are likely due to genetic expression that pre-dates selection; in the formal parlance of weed science this is described as natural tolerance. Leaf tissues from glufosinate-treated and non-treated seedlings were harvested 24 h after treatment (HAT) for RNA-Seq analysis. Global gene expression was measured using Illumina DNA sequence reads from non-treated and treated surviving (presumably tolerant, T) and susceptible (S) plants. The same plants were used to determine the mechanisms conferring differential tolerance to glufosinate. The S plants accumulated twice as much ammonia as did the T plants, 24 HAT. The relative copy number of the glufosinate target gene GS2 did not differ between T and S plants, with 1 to 3 GS2 copies in both biotypes. A reference cDNA transcriptome consisting of 72,780 contigs was assembled, with 65,282 sequences putatively annotated. Sequences of GS2 from the transcriptome assembly did not have polymorphisms unique to the tolerant plants. Five hundred sixty-seven genes were differentially expressed between treated T and S plants. Of the upregulated genes in treated T plants, 210 were more highly induced than were the upregulated genes in the treated S plants. Glufosinate-tolerant plants had greater induction of ABC transporter, glutathione S-transferase (GST), NAC transcription factor, nitronate monooxygenase (NMO), chitin elicitor receptor kinase (CERK1), heat shock protein 83, ethylene transcription factor, heat stress transcription factor, NADH-ubiquinone oxidoreductase, ABA 8’-hydroxylase, and cytochrome P450 genes (CYP72A, CYP94A1). Seven candidate genes were selected for validation using quantitative real time-PCR. While GST was upregulated in treated tolerant plants in at least one population, CYP72A219 was consistently highly expressed in all treated tolerant biotypes. These genes are candidates for contributing tolerance to glufosinate. Taken together, these results show that differential induction of stress-protection genes in a population can enable some individuals to survive herbicide application. Elevated expression of detoxification-related genes can get fixed in a population with sustained selection pressure, leading to evolution of resistance. Alternatively, sustained selection pressure could select for mutation(s) in the GS2 gene with the same consequence.

show abstract

Section: Methodsmentioning

confidence: 99%

RNA-Seq transcriptome analysis of Amaranthus palmeri with differential tolerance to glufosinate herbicide

Salas-Perez

Saski²,

Noorai³

et al. 2018

PLoS ONE

View full text Add to dashboard Cite

show abstract

“…Difenzoquat did not cause nitrite accumulation in A fatua or barley under light conditions 23. Paraquat caused leakage of nitrite from cucumber ( Cucumis sativa L) cotyledon discs 26. These results provide indirect evidence that difenzoquat under light conditions does not inhibit photosynthesis, which is contrary to the light‐dependent phytotoxic action of paraquat.…”

Section: Resultsmentioning

confidence: 82%

Contact activity of difenzoquat differs from that of paraquat

Nandula

2003

Pest Management Science

View full text Add to dashboard Cite

Difenzoquat herbicide is used for post-emergence control of wild oat (Avena fatua L) in small grain crops. Its mechanism of action is not known, but appears to have both paraquat-like contact activity and systemic growth-inhibition activity. Experiments were conducted in vitro to compare the contact activity of difenzoquat and paraquat, to examine the contact activity of difenzoquat in difenzoquat-resistant (accession LCS) and -susceptible (accession SB 18) A fatua biotypes and -tolerant 'Ernest' and -susceptible 'Verde' hard red spring wheat (Triticum aestivum L) cultivars, and to investigate the role of differential DNA synthesis as a mechanism for difenzoquat resistance. Difenzoquat at 1 mM induced significant electrolyte leakage from resistant and susceptible A fatua leaf tissue in both light and dark, but paraquat at 1 mM induced electrolyte leakage only in light and not in dark. Difenzoquat at 1 mM under light induced more electrolyte leakage from resistant and susceptible A fatua than from tolerant 'Ernest' and susceptible 'Verde' wheat. Paraquat under light conditions induced more electrolyte leakage than difenzoquat, but no significant differences among A fatua accessions and wheat cultivars were detected. Difenzoquat under light did not decrease chlorophyll levels for either A fatua accessions or wheat cultivars, whereas paraquat decreased chlorophyll content of all four plant types. Inhibition of DNA synthesis was not significantly different between susceptible and resistant A fatua, but was significantly greater in susceptible 'Verde' than tolerant 'Ernest' wheat. These data suggest that difenzoquat and paraquat, have different modes of contact activity.

show abstract

“…Ammonia level was determined by adding 150 μL of water, 100 μL of phenol nitroprusside solution, and 50 μL of alkaline hypochlorite solution. 23 After 30 min incubation at room temperature, absorbance was measured at 540 nm as described above.…”

Section: ■ Materials and Methodsmentioning

confidence: 99%

Physiological Factors Affecting Uptake and Translocation of Glufosinate

Takano

Beffa

Preston

et al. 2020

J. Agric. Food Chem.

View full text Add to dashboard Cite

Glufosinate is considered a contact herbicide because of its fast activity and limited translocation in plants. We used Palmer amaranth (Amaranthus palmeri S. Watson) as a model species to study plant-related factors affecting glufosinate uptake and translocation. Glufosinate uptake increased rapidly during the initial 24 h, achieving maximum uptake from this time on. The rate of uptake saturated with doses higher than 250 μM glufosinate, suggesting the involvement of a membrane transporter. When glufosinate concentrations were higher (>1 mM), uptake was a simple diffusion process in favor of a concentration gradient between the inside and the outside of the cells. Glufosinate uptake was inhibited by the presence of glutamine. The fast action of glufosinate did not limit its own translocation. Because glufosinate is highly water soluble, it translocates mostly through the apoplast or the xylem system. Consequently, old leaves tend to accumulate more herbicide than young meristematic leaves.

show abstract

Microbioassays to Determine the Activity of Membrane Disrupter Herbicides

Cited by 9 publications

References 0 publications

RNA-Seq transcriptome analysis of Amaranthus palmeri with differential tolerance to glufosinate herbicide

RNA-Seq transcriptome analysis of Amaranthus palmeri with differential tolerance to glufosinate herbicide

Contact activity of difenzoquat differs from that of paraquat

Physiological Factors Affecting Uptake and Translocation of Glufosinate

Contact Info

Product

Resources

About