mRNA molecules form an intermediate in the transfer of sequences from DNA to ribosomes in order to guide protein production. Errors can be introduced into mRNA, producing aberrant proteins which place a strain on cellular regulatory machinery, causing increased risks of apoptosis, cancer, and decreased fitness. These errors may be introduced due to decreased transcriptional proofreading capabilities, exposure to chemicals, or mistakes in RNA editing machinery. It is important to investigate these causes of transcription errors to better understand the long-neglected area of mRNA fidelity which has such significant impacts on our cellular functions. In this paper, it was determined that addition of adenine opposite from abasic sites, not genomic uracil pairing with adenine, are a probable cause of G-to-A transcription errors. That exposure to Roundup causes increased levels of transcription errors, potentially due to oxidative stress. And finally, that off-target ADAR gene editing of transcripts occurs at high levels.

The resistance of Palmer amaranth (PA) and the tolerance (natural resistance) of pitted morningglory (PM) to glyphosate have made these species among the most common and troublesome weeds in the southeastern U.S. since the adoption of glyphosate-resistant (GR) crops. Populations of GR PA (R1 and R2) were identified in Mississippi. The inheritance of glyphosate resistance was examined in reciprocal crosses (RC) between glyphosate-resistant (R) and -susceptible (S) parents (Female-S × Male-R, S/R, and Female-R × Male-S, R/S), and second reciprocal crosses (2RC) (Female-S/R × Male-S/R, S/R//S/R, and Female-R/S × Male-R/S, R/S//R/S). Dose-response assays resulted in 17- to 4old resistance to glyphosate compared with S. Population S accumulated 325- and 8-times more shikimate at the highest glyphosate dose than in R1 and R2, respectively. cDNA sequence analysis of the 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) gene indicated no target site mutation. Genomes of R1, R2, RC, and 2RC contained from 1- to 59old more copies of EPSPS gene than S; EPSPS was highly expressed in R1 and R/S, but was poorly expressed in S, S/R, and R2. EPSPS activity was lower in S and S/R than in R and R/S, glyphosate absent; all were inhibited by glyphosate. Western Blot analysis confirmed an increased EPSPS protein level to EPSPS copy number correlation. Thus, the level of resistance was decidedly influenced by the direction of the cross. R and S female plants were reproductively isolated and seed were still produced, suggesting that PA can produce seed both apomictically and sexually (facultative apomixis). This mode of reproduction determined the low copy number inheritance, as well as guaranteeing the GR trait stability in the R populations. Dose-response assays resulted in 2.6old variability in tolerance to glyphosate between the most tolerant (MT) and the least tolerant (LT) PM populations. The level of tolerance positively correlated with the time of exposure to GR-crop system. Less shikimate was recovered in MT as compared to LT. Levels of aminomethylphosphonic acid (AMPA) were not different between populations and sarcosine was not present in either populations. Consequently, metabolism of glyphosate to AMPA or sarcosine is not a common factor in explaining natural resistance levels.

Many fire-prone forests in western North America suffer from hazardous fuel conditions. Mechanical mastication is an increasingly common method of fuels treatment, but little is known regarding long-term effectiveness. A randomized block design at two sites (northern Sierras and southern Cascades) compared ladder fuels and overstory growth among treatments including mastication alone and mastication followed with prescribed fire or herbicide 10 or 11 years post-treatment. Subsequent herbicide application reduced ladder fuels in comparison to mastication alone or with prescribed fire. Prescribed fire further reduced ladder fuels at the southern Cascades site, however, in the northern Sierras postire ladder fuels were positively related to overstory absence. Mastication alone effectively released ponderosa pine at the southern Cascades site, whereas neither herbicide nor prescribed fire affected pine radial growth. This study demonstrates the feasibility of prescribed fire and herbicide for increasing treatment longevity of mastication, but also highlights potential limitations and important considerations.

The application of commercial herbicide restricts weed growth and significantly improves control over crop vitality and yield. Despite their utility in the agriculture sector, herbicides have the potential to contaminate local water sources. To minimize environmental impacts, the development of efficient separation processes to clean-up contaminated water bodies is necessary. However, complex speciation and conformational flexibility in the condensed phase poses a significant challenge. In this work, we investigate structure and speciation of three common organic herbicides (glyphosate, atrazine, and metolachlor) in aqueous solution. We employ the PBE-D3 density functional to perform ab initio molecular dynamics (MD) simulations in the canonical and isothermal-isobaric ensembles. We analyze MD trajectories to understand hydrogen bonding dynamics and lifetime as well as diffusional and vibrational characteristics. To enhance configurational sampling, we conduct metadynamics simulations to obtain the free energies of dissociation and intramolecular proton transfer of glyphosate.

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Weeds pose a challenge to cotton production, and herbicides have been the primary means of control. However, there is growing concern over weed resistance to herbicides. To address this issue, we evaluated three cover crop species and six cotton accessions for weed suppression. The study found that hairy vetch, wheat, and B16 cotton CS line effectively suppressed Amaranthus species, while MNTN 4-15, B16, hairy vetch, and wheat were correlated with the highest cotton yield. Cover crops were also analyzed for chlorogenic acid content, with wheat, MNTN 4-15, and hairy vetch producing the highest amounts. The greenhouse tray study showed that wheat and hairy vetch cover crops were among the best treatments for weed suppression. These findings suggest that cover crops may provide effective weed control and improve crop yield.

Glyphosate is a broad-spectrum herbicide that is used globally to combat the spread of weeds among crops. Not all countries around the world have been using the herbicide. For example, island countries such as Dominica and St. Kitts and Nevis do not use the herbicide on their crops. However, St. Kitts and Nevis imports food and other agricultural products from around the world, leading to the hypothesis that glyphosate is contaminating the soil through those imported products. The aim of this research project was to determine if glyphosate is present in the island country of St. Kitts and Nevis. A field test that will provide a rapid yes/no indication of the presence of glyphosate in sand samples on the islands and in food samples entering St. Kitts and Nevis was developed. Various models of contamination were studied, and a model experiment was set up a simulate possible contamination scenario. A model experiment was conducted simulating rainwater washing glyphosate from food scraps into the surrounding area. Tomatoes were chosen to simulate the food scraps and were tested for glyphosate contamination. After conducting the model experiment, the sand underneath the food scraps as well as the water runoff were tested for glyphosate. From the experiment, a glyphosate concentration of 322.7 ppm was calculated in the internal tomato. Also from the raindrop model experiment, 51.9 ppm glyphosate was detected in the sand samples and 17.0 ppm glyphosate was detected in the collected runoff water. Therefore, since glyphosate was recovered in both areas tested in the raindrop experiment, it proves that glyphosate can be introduced into the environment through imported foods contaminated with glyphosate.

New low volatile formulations of dicamba and 2,4-D are being developed to reduce injury to non-tolerant crops. Experiments were conducted comparing dicamba and 2,4-D volatility as affected by formulation, soil moisture content and soil texture. All formulations were applied to soil contained in greenhouse flats. After application greenhouse flats were then placed between a bio-indicator row of cotton and soybean. An open ended plastic dome covered the treated flats and crops for 48 hours prior to removal. Plant heights and yield of bio-indicator crops were unaffected by 2,4-D and dicamba volatility. Soil texture and moisture content did not significantly affect volatility. The greatest soybean crop injury was observed following application of the dimethylamine salt of dicamba and cotton injury was greatest following application of the ethylhexylester salt of 2,4-D. Volatility was generally reduced with new formulations of dicamba or 2,4-D; however, volatility was not completely eliminated.

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