Non-treated Control Research Articles

Evaluation of fungicides to manage rice false smut (Ustilaginoidea virens) in the hills of Nepal

Rice False Smut (RFS) caused by Ustilaginoidea virens is a major emerging disease of rice due to expanded area of hybrid rice cultivars, increasing use of nitrogenous fertilizers and change in climate. Due to the increasing incidences of this disease across the globe, there is a pressing need to develop techniques for false smut management. The application of fungicides with high efficiency, low toxicity, and low residue is currently the best option to control RFS. Therefore, current research was conducted to determine the effectiveness of fungicides to manage RFS. The experiments were conducted in a completely randomized block design with three replications of seven treatments at RFS-prone subtropical hills of Nepal in the main rice growing season, during 2020 and 2021. The fungicides include trifloxystrobin 25 % + tebuconazole 50 %, chlorothalonil 75 %, carbendazim 12 % + mancozeb 63 %, propiconazole 25 %, azoxystrobin 50 %, carbendazim 50 % and untreated control. Fungicides were applied as two foliar sprays, one at booting and the other at flowering. Fungicide spray significantly increased number of tillers per plant (P ≤ 0.01) and reduced the number of false smut-infected tillers per plant (P ≤ 0.05), false smut severity (P ≤ 0.05), and incidence (P ≤ 0.05). False smut incidence percentages were significantly reduced by all the fungicides except mancozeb + carbendazim compared to the non-treated control. The reduction in RFS incidence was 70 % in propiconazole, 71 % in trifloxystrobin + tebuconazole sprayed plots compared to the non-treated control plots. Thus, the application of suitable fungicide at the appropriate stage would give the satisfactory suppression of RFS in a farmers' field in Nepal.

Rice response to fluridone following topsoil removal on a precision‐leveled field

AbstractFurrow‐irrigated rice (Oryza sativa L.) production requires additional management options without the cultural strategy of a flood. In 2023, fluridone (Brake) was registered for use in rice production. Precision‐leveling land is an important aspect of maintaining an effective irrigation flow path; however, the removal of topsoil can severely impact crop response from residual herbicides. The objective of this study was to evaluate the impact of fluridone on rice response when applied to a precision‐leveled field following topsoil removal. An on‐farm field study was conducted in 2023 near Osceola, AR, with a Sharkey‐Steele clay complex soil texture. The study consisted of six herbicide treatments applied at the rice three‐leaf stage. These treatments included clomazone, quinclorac, and fluridone at three rates (0.5×, 1×, and 2× of a label rate) and a nontreated control. Across evaluation times, maximum visual rice injury was greater than 25% and 65% for the fluridone 1× and 2× treatments, respectively. Rice canopy coverage was reduced in the fluridone 1× and 2× treatments compared to all other treatments from 6 to 10 weeks after application (WAA). Rice heading in the fluridone 2x treatment was delayed by more than 60 and 30 percentage points at 11 and 12 WAA, respectively, compared to all other treatments. Rough rice yield in the fluridone 2× treatment was reduced by 21% compared to all other treatments. Overall, fluridone 1× and 2× rates caused substantial rice injury and would not be recommended on a precision‐leveled field.

The Impact of Tadbir as a Pre-Application Treatment of Medicinal Plants on Their Chemical Profiles and Biological Activities in Traditional Persian Pharmacy

Based on basic traditional medicine practice, many plants undergo primary treatments to improve their pharmacological characteristics or to attenuate unwanted or unfavorable features of drugs before incorporating them into drug formulations. These treatments are called “Tadbir” in Traditional Persian Medicine (TPM). The purpose of these processes includes but is not limited to eliminating unnecessary compounds, excluding harmful properties such as toxicity and poignancy, and improving their overall natural properties and effectiveness. Here, the effect of vinegar and acetic acid treatment on three herbal specimens, including Carum carvi L. fruits (CC), Trachyspermum ammi (L.) Sprague fruits (TA), and Nigella sativa L. seeds (NS) were investigated. The treated and non-treated samples were subjected to essential oil and methanol extraction. Further, to assess the alterations in the essential oil constituents caused by Tadbir, samples were analyzed by Gas Chromatography/Mass Spectrometry (GC/MS) and HPTLC fingerprinting techniques. Total phenol and flavonoid content and DPPH free radical scavenging activity of methanol extracts were evaluated. As a result of the treatments, TA extracts showed significant rise in phenol and flavonoid contents. Total phenol content increased from 98.50±1.01 in non-treated increased to 181.20±0.27 mg GAE/g Ext. in the vinegar-treated TA fruit extract and total flavonoid showed a rise from 8.97±1.12 to 12.89±0.41 mg QE/g Ext. This may be the reason behind its lower IC50 values in DPPH free radical scavenging assay. Interestingly, Tadbir treatment of TA fruits with 4% acetic acid, lowered the IC50 value from 1019.42±75.65µg/mL in non-treated control to 274.2±17.22 µg/mL; while vinegar caused a lower degree of reduction in IC50 value (369.4±5.54 µg/mL) in DPPH free radical scavenging assay. However, CC fruit extracts, showed a decrease in phenolic content; while demonstrating an increase in flavonoids. Interestingly, phenol and flavonoid contents were significantly enhanced in treated NS seed extracts. The results of all extracts were found significantly different (p<0,05) from each other and the non-treated control. The conclusive results of the present study may partly justify the pre-application of Tadbir treatments of medicinal plants in traditional pharmacy.

Salt stress alleviation in Calendula officinalis L. by potassium nanoparticles application and Streptomyces bacteria inoculation

The current study was conducted to mitigate salt stress on Calendula officinalis L. plants using Streptomyces (Sm) bacteria alone or in combination with potassium nanoparticles (K NPs). Based on the results, morphometric characters, leaf SPAD and relative water content in plants treated with Sm bacteria and K NPs increased compared to the nontreated control under salinity stress. However, leaf ionic leakage, malondialdehyde (MDA) and hydrogen peroxide (H2O2) content decreased considerably in these treated plants. Also, under salt stress, the activity of antioxidant enzymes was higher in Sm bacteria + K NPs -treated plants than in controls. In all plants, endogenous indole acetic acid (IAA) content increased compared to plants grown in non-saline conditions. Inoculated plants reflected a relative increase in IAA by about 28% over the uninoculated plants. The highest amount of abscisic acid (ABA) and putrescine (Put) was related to those plants treated with Sm bacteria + K NPs, which the amounts were 43% and 47% higher than in control plants, respectively. Application of Sm bacteria + K NPs had a helpful outcome on both macronutrients (N-NO- 3, P, K and Mg) and micronutrients (Fe, Zn, and Mn) of vines leaves. In general, the inoculation of Sm bacteria + K NPs application by improving the uptake of nutrients, regulating phytohormones and increasing the antioxidant enzymes activity resulted in salinity tolerance improvement in calendula plants.

Optimizing fungicide programs for peanut leaf spot management in Southeast Alabama: A case for reducing chlorothalonil use

Early leaf spot (caused by Passalora arachidicola) and late leaf spot (Nothopassalora personata) are the most damaging fungal diseases of peanuts (Arachis hypogaea L.) in the southeastern United States. Producers rely heavily on single-site fungicides, which pose a moderate to high risk for resistance development. To mitigate this risk, chlorothalonil, the predominate multi-site fungicide used to manage leaf spot diseases in peanuts, is the backbone of leaf spot spray programs. However, the future availability of chlorothalonil in agriculture is at risk due to regulatory decisions and toxicity issues. Thus, this study was undertaken to evaluate the efficacy of copper sulfate, dodine, and sulfur alone or in combination with other single-site fungicides against leaf spot diseases as chlorothalonil alternatives as well as their influence on yield. Under low disease pressure, all the alternative fungicide programs provided statistically similar leaf spot control when compared to chlorothalonil alone. In contrast, under high disease pressure in 2022, dodine alone and dodine + penthiopyrad did not significantly decrease leaf spot severity when compared to the nontreated control. Additionally, dodine alone and the 2022 premium fungicide program had significantly higher leaf spot severity when compared to chlorothalonil alone under favorable weather patterns for rapid disease development. Sulfur + copper sulfate significantly reduced leaf spot severity as compared to chlorothalonil alone only in 2022. All other remaining fungicide programs provided statistically similar control as chlorothalonil alone. Overall, dodine, sulfur, and copper sulfate have potential to serve as alternatives to chlorothalonil in leaf spot fungicide spray programs in peanuts.

Financial implications of treating nonsevere Gram-negative clinical mastitis in three California dairies

On 3 large California dairies, 415 lactating cows with nonsevere clinical mastitis (CM) and infected with Gram-negative (GN) bacteria were randomly assigned to one of 3 treatment groups: nontreated control (CON - 135 cases), 2d ceftiofur HCl (SP2 - 133 cases), or 5d ceftiofur HCl (SP5 - 147 cases). Bacteriological cure (BC), clinical cure (CC), mastitis recurrence (MR), culling/death, and overall treatment success differed among treatment groups. Although duration of milk withheld due to mastitis therapy was higher for SP5 (9.4 d), there was no difference between CON (6.9 d) and SP2 (7.1 d). Culling and death rates due to GN CM were the main effects that impacted partial cost calculations. Of study cows culled across the 3 herds, a higher proportion of CON cows (25%) were culled compared with SP2 (11%) or SP5 (18%). Mastitis-related expenses were higher ($550) for CON than SP2 ($343) or SP5 ($423). Results of this partial budget evaluation for the 3 California dairies indicated economic justification for treating cases of nonsevere GN CM with ceftiofur HCl for 2 d.

Response of selected peanut commercial cultivars to leaf spot diseases as influenced by fungicide inputs

Early leaf spot (caused by Passalora arachidicola) and late leaf spot (caused by Nothopassalora personata) are the most widespread, damaging foliar diseases of peanuts in the southeastern United States. When left nontreated, both diseases can prematurely defoliate peanuts and reduce peanut yields by up to 70%. Leaf spot diseases are primarily managed through a combination of fungicide applications and cultivar selection. In this study, six field experiments were conducted from 2021 to 2022 in Brewton, Headland, and Tallassee, Alabama, to evaluate the response of ten selected commercial peanut cultivars to various levels of leaf spot pressure as influenced by low- and high-input fungicide programs when compared to nontreated controls. The low input fungicide program included seven applications of chlorothalonil, whereas the high input fungicide program comprised of fluxapyroxad, pyraclostrobin, mefentrifluconazole, flutolanil, bixafen, flutriafol, tebuconazole, and/or chlorothalonil. Effects on leaf spot and pod yields were assessed. Leaf spot severity was higher for TUFRunner™ ‘297’, Georgia-16HO, and FloRun ‘331’, but was lower for AU-NPL 17, Georgia-06G, Georgia-12Y, and Georgia-14N. In terms of yield, leaf spot tolerant varieties showcased superior performance in high disease pressure, whereas susceptible varieties excelled in low disease pressure. Fungicides significantly enhanced the performance of susceptible cultivars under high leaf spot pressure, with marginal impact in low leaf spot pressure. These results highlight the importance of selecting cultivars and fungicide spray programs based on disease pressure to maximize profits.

Response of Tahitian Bridal Veil (Gibasis pellucida) and Small-Leaf Spiderwort (Tradescantia fluminensis) to Postemergence Herbicides under Greenhouse Conditions.

Tahitian bridal veil (Gibasis pellucida) and small-leaf spiderwort (Tradescantia fluminensis) are both invasive species in natural areas throughout Florida. However, very little is known regarding herbicide control. To provide land managers with herbicidal control options for both species, postemergence herbicides were evaluated for efficacy in a greenhouse to identify herbicide options that control both species under similar settings. Four herbicides, including triclopyr acid, triclopyr amine + 2,4-D amine, triclopyr amine, and glufosinate were applied at standard label rates and compared to a non-treated control group for efficacy. Visual control ratings were taken at 2, 4, and 8 weeks after treatment (WAT), and shoot dry weights (WAT 8) and regrowth dry weights (WAT 12) were determined. Triclopyr (acid and amine) generally provided the most consistent control of both species as evidenced by the visual control ratings and shoot dry weight data which showed reductions of 76% to 89% in shoot biomass at trial conclusion. Triclopyr + 2,4-D reduced shoot dry weights by 52% to 54% and was the least effective when considering the control of both species.

Evaluating the vegetative and reproductive response of hemp (Cannabis sativa) to simulated off-target events of 2,4-D and dicamba

Abstract Introducing soybean cultivars resistant to 2,4-D and dicamba allowed for postemergence applications of these herbicides. These herbicides pose a high risk for off-target movement, and the potential influence on crops such as hemp is unknown. Two studies were conducted from 2020 through 2022 in controlled environments to evaluate hemp response to rates simulating off-target events of 2,4-D and dicamba. The objectives of this study were to: 1) determine the effects of herbicide (2,4-D and dicamba) and rate (1x to 1/100,000x labeled rate) on visible injury, height, and branching, and 2) determine the effect of 2,4-D rate (1x to 1/100,000x labeled rate) on visible injury, height, branching, and reproductive parameters. Herbicides were applied in the early vegetative stage, and evaluations took place 14 and 28 days after treatment (DAT) and at trial termination (42 DAT in the greenhouse trial and at harvest in the growth chamber trial). In the greenhouse trial, 2,4-D and dicamba at the 1x rate and the 1/10x rate caused 68, 78, and 20% injury 28 DAT, respectively. At the time of trial termination 42 DAT, plants treated with 1x rates of 2,4-D and dicamba or 1/10x dicamba were 19, 25, and 9 cm shorter than the nontreated control, respectively. At trial termination, simulated off-target rates of 2,4-D and dicamba did not influence branching or plant weight. In the growth chamber study, the 1x and 1/10x rates of 2,4-D caused 82% and 2% injury 28 DAT, respectively. Plant height, fresh weight, and cannabidiol (CBD) levels of plants treated with simulated off-target rates of 2,4-D were not different from the nontreated control. These studies suggest that hemp grown for CBD exposed to off-target rates of 2,4-D or dicamba in early vegetative stages may not have distinguishable effects 42 DAT or at harvest.

Grain Sorghum Response to Simulated Fomesafen and Terbacil Carryover from Watermelons in Georgia

Abstract Georgia growers can benefit from double-cropping grain sorghum following watermelon to maximize land use and add economic value to their operations. However, capitalizing on the economic advantages of harvesting two crops within a single season must account for potential herbicide injury to rotational crops. An integrated weed management strategy that includes a preplant application of fomesafen and terbacil is recommended for weed control in watermelon production systems. However, currently labeled plant-back restrictions for grain sorghum require a minimum of 10 and 24 months for fomesafen and terbacil, respectively. Therefore, this research aimed to determine the tolerance of grain sorghum to fomesafen and terbacil following soil applications applied 90 to 100 d before planting (DBP). Experiments were conducted at the University of Georgia Ponder Research Farm from 2019 to 2023. The experimental design was a randomized complete block with 4 replications. Five rates of fomesafen (35, 70, 140, 210, 280 g ai ha-1), four rates of terbacil (3.5, 7.0, 10.5, 14.0 g ai ha-1) and a non-treated control, were evaluated. In 2019, fomesafen caused significant sorghum leaf necrosis, plant density reductions, height reductions, and yield reductions of at least 16%, especially when applied at rates ≥ 210 g ai ha-1. Terbacil had little to no effect on sorghum injury, density, height, or yield in any year. These results suggest that sorghum has sufficient tolerance to terbacil when applied 90-100 DBP. In 4 of 5 years, sorghum had an acceptable tolerance to fomesafen when applied 90 to 100 DBP. However, yield losses observed in 2019 suggest that caution should be taken when fomesafen is applied 90 to 100 DBP grain sorghum at ≥ 210 g ai ha-1.

Utilizing Disease Prediction Models to Time Fungicide Applications for Controlling Ripe Rot, Caused by Colletotrichum spp., in Maryland Vineyards.

Two previously published ripe rot prediction models, DF2-NN and GH2-DT, were evaluated for fungicide application timing efficacy in Maryland vineyards. Both models utilize leaf wetness duration (LWD), temperature, and grape cluster phenological stages as model parameters. These three parameters were tracked throughout the 2021 to 2023 seasons in three vineyards. The fungicide efficacy trials started at the veraison phenological stage and included a nontreated control, a 12-day interval treatment, and two model-triggered treatments when risk predicted by the models crossed a threshold. The severity of ripe rot on the clusters in each treatment was assessed when the fruit were mature. Ripe rot severity in the nontreated controls was higher during seasons with more LWD and more precipitation. Days in which the models were triggered by the environmental conditions primarily coincided with precipitation events and lengthy LWDs. The model-triggered treatments never had significantly higher ripe rot severity than the 12-day interval treatment but had significantly lower severities than the nontreated control in most trials which had high ripe rot pressure. Furthermore, the model-triggered treatments resulted in fewer fungicide applications than the 12-day interval treatment on average. The DF2-NN model appeared to be more accurate and useful for ripe rot prediction and treatment than the GH2-DT model because it triggered fewer fungicide applications while reducing ripe rot. This model may be useful for improving or maintaining ripe rot control with fewer fungicide inputs, which may be beneficial for the environment and the reduction of fungicide resistance selection.

Conventional and novel anti-seizure medications reveal a particular role for GABAA in a North Sea progressive myoclonus Epilepsy Drosophila model

ObjectiveNorth Sea Progressive Myoclonus Epilepsy (NS-PME) is a rare genetic disorder characterized by ataxia, myoclonus and seizures with a progressive course. Although the cause of NS-PME is known, namely a homozygous mutation in the GOSR2 gene (c.430 G>T; p. Gly144Trp), sufficient treatment is lacking. Despite combinations of on average 3–5 anti-seizure medications (ASMs), debilitating myoclonus and seizures persist. Here we aimed to gain insight into the most effective anti-convulsive target in NS-PME by evaluating the individual effects of ASMs in a NS-PME Drosophila model. MethodA previously generated Drosophila model for NS-PME was used displaying progressive heat-sensitive seizures. We used this model to test 1. a first-generation ASM (sodium barbital), 2. common ASMs used in NS-PME (clonazepam, valproic acid, levetiracetam, ethosuximide) and 3. a novel third-generation ASM (ganaxolone) with similar mode of action to sodium barbital. Compounds were administered by adding them to the food in a range of concentrations. After 7 days of treatment, the percentage of heat-induced seizures was determined and compared to non-treated but affected controls. ResultsAs previously reported in the NS-PME Drosophila model, sodium barbital resulted in significant seizure suppression, with increasing effect at higher dosages. Of the commonly prescribed ASMs, clonazepam and ethosuximide resulted in significant seizure suppression, whereas both valproic acid and levetiracetam did not show any changes in seizures. Interestingly, ganaxolone did result in seizure suppression as well. ConclusionOf the six drugs tested, three of the four that resulted in seizure suppression (sodium barbital, clonazepam, ganaxolone) are primary known for their direct effect on GABAA receptors. This suggests that GABAA could be a potentially important target in the treatment of NS-PME. Consequently, these findings add rationale to the exploration of the clinical effect of ganaxolone in NS-PME and other progressive myoclonus epilepsies.

Electron Beam-Supported Fabrication of Biocompatible Silver/iota-Carrageenan for Wound Healing Application.

Silver nanoparticles (AgNPs) are a potent antibacterial agent, especially when used to treat bacteria that are multidrug resistant. However, it is challenging to eliminate the hazardous reducing agents that remain in AgNPs produced by the conventional chemical reduction process. To overcome these challenges, the presented research demonstrates the fabrication of AgNPs using iota-carrageenan (ι-carra) as a carbohydrate polymer using electron beam (EB) irradiation. Well-characterized ι-carra@AgNPs have a face-centered cubic (FCC) structure with spherical morphology and an average size of 26 nm. Herein we explored the approach for fabricating ι-carra@AgNPs that is suitable for scaling up the production of nanoparticles that exhibit excellent water stability. Further, the optimized ι-carra@AgNPs exhibited considerable antibacterial activity of 40% and 30% inhibition when tested with Gram-negative Escherichia coli ATCC 43895 and Gram-positive Staphylococcus aureus (S. aureus) (ATCC 6538), respectively, and low cytotoxicity at 10-50 μg/mL. To establish the potential biomedical application, as proof of the concept, the ι-carra@AgNPs showed significant antibiofilm activity at 20 μg/mL and also showed 95% wound healing abilities at 50 μg/mL compared to the nontreated control groups. Electron beam assisted ι-carra@AgNPs showed significant beneficial effects against specific bacterial strains and may provide a guide for the development of new antibacterial materials for wound dressing for large-scale production for biomedical applications.

Effects of plant protease inhibitors (Pep-3-EcTI, Pep-BbKI, and Pep-BrTI) versus corticosteroids on inflammation, remodeling, and oxidative stress in an asthma-COPD (ACO) model.

The peptide derived from E. contortisiliquum trypsin inhibitor (Pep-3-EcTI), peptide derived from kallikrein inhibitor isolated from B. bauhinioides (Pep-BbKI), and B. rufa peptide modified from B. bauhinioides (Pep-BrTI) peptides exhibit anti-inflammatory and antioxidant activities, suggesting their potential for treating asthma-chronic obstructive pulmonary disease (COPD) overlap (ACO). We compared the effects of these peptides with dexamethasone (DX) treatment in an ACO model. In this study, 11 groups of male BALB/c mice were pre-treated under different conditions, including sensitization with intraperitoneal injection and inhalation of ovalbumin (OVA), intratracheal instillation of porcine pancreatic elastase (ELA), sensitization with intraperitoneal injection, and various combinations of peptide treatments with Pep-3-EcTI, Pep-BbKI, Pep-BrTI, dexamethasone, and non-treated controls (SAL-saline). Respiratory system resistance, airway resistance, lung tissue resistance, exhaled nitric oxide, linear mean intercept, immune cell counts in the bronchoalveolar lavage fluid, cytokine expression, extracellular matrix remodeling, and oxidative stress in the airways and alveolar septa were evaluated on day 28. Results showed increased respiratory parameters, inflammatory markers, and tissue remodeling in the ACO group compared to controls. Treatment with the peptides or DX attenuated or reversed these responses, with the peptides showing effectiveness in controlling hyperresponsiveness, inflammation, remodeling, and oxidative stress markers. These peptides demonstrated an efficacy comparable to that of corticosteroids in the ACO model. However, this study highlights the need for further research to assess their safety, mechanisms of action, and potential translation to clinical studies before considering these peptides for human use.

Preemergence Herbicides and Mulches for Cutting Propagation—Impact on Rooting, Growth after Transplant, and Weed Control

Weed control in cutting propagation is limited to manual hand weeding, which is time-consuming and labor-intensive. Preemergence herbicides and mulches may be viable weed control methods for cutting propagation, but crop safety and weed control efficacy must be better understood. Four preemergence herbicides (indaziflam, isoxaben, isoxaben + dithiopyr, and oxyfluorfen + oxadiazon) and two mulches (pine pellets and rice hulls) were assessed in cutting propagation for their impact on rooting and subsequent liner growth (butterfly bush [Buddleja davidii Franch.] and crape myrtle [Lagerstroemia indica L.]) and control of four common weed species. Butterfly bush cuttings had lower rooting percentage and root dry weight with isoxaben and isoxaben + dithiopyr, but no damage was observed for all other treatments during propagation or after transplant. Crape myrtle cutting root development and liner growth were statistically similar for all treatments compared to the non-treated control. Isoxaben, isoxaben + dithiopyr, oxyfluorfen + oxadiazon, and pine pellets provided excellent control (87 to 100%) of all four weed species tested. Overall, several preemergence herbicides and mulches were safe for use in cutting propagation and effective weed control varied by product and weed species.

Effect of Methyl Jasmonate on the Performance of Tetranychus evansi Baker & Pritchard, 1960 (Acari: Tetranychidae) and Phytoseiulus longipes Evans, 1968 (Acari: Phytoseiidae) on Tomato Plants

Inducible anti-herbivore defenses in plants are predominantly regulated by jasmonic acid (JA). The red spider mite Tetranychus evansi Baker & Pritchard, 1960 (Acari: Tetranychidae) is an invasive pest known for its detrimental impact on tomato plants and other Solanaceae crops. Here, we investigated the extent to which T. evansi and the predatory mite Phytoseiulus longipes Evans, 1968 (Acari: Phytoseiidae) are affected by induced JA-defenses. Initially, we artificially induced the JA-response in tomato plants using exogenous methyl jasmonate (MeJA) and subsequently assessed the effect of JA defenses on spider mite by evaluating mortality and oviposition rates. Our findings revealed a higher mortality and lower oviposition rates on plants treated with MeJA compared to non-treated control plants. Furthermore, we examined the predatory mite's predation rates on spider mite eggs produced on MeJA-treated and non-treated tomato plants. The results showed a reduced predation on T. evansi eggs derived from MeJA-treated plants, indicating a potential negative impact of JA-induced defenses on the predator's performance. Finally, we released five predatory females on T. evansi-infested tomato plants treated and non-treated with MeJA, monitoring the predator population density for three generations. Predator population was not affected, as the abundance of larvae and adults was not significantly different between treatments. These findings underscore the negative impact of JA defenses on herbivores and highlight the trade-off it may pose on natural enemies.

Natural Killer Cell‐Derived Extracellular Vesicles as Potential Anti‐Viral Nanomaterials

In viral infections, natural killer (NK) cells exhibit anti-viral activity by inducing apoptosis in infected host cells and impeding viral replication through heightened cytokine release. Extracellular vesicles derived from NK cells (NK-EVs) also contain the membrane composition, homing capabilities, and cargo that enable anti-viral activity. These characteristics, and their biocompatibility and low immunogenicity, give NK-EVs the potential to be a viable therapeutic platform. This study characterizes the size, EV-specific protein expression, cell internalization, biocompatibility, and anti-viral miRNA cargo to evaluate the anti-viral properties of NK-EVs. After 48 h of NK-EV incubation in inflamed A549 lung epithelial cells, or conditions that mimic lung viral infections such as during COVID-19, cells treated with NK-EVs exhibit upregulated anti-viral miRNA cargo (miR-27a, miR-27b, miR-369-3p, miR-491-5p) compared to the non-treated controls and cells treated with control EVs derived from lung epithelial cells. Additionally, NK-EVs effectively reduce expression of viral RNA and pro-inflammatory cytokine (TNF-α, IL-8) levels in SARS-CoV-2 infected Vero E6 kidney epithelial cells and in infected mice without causing tissue damage while significantly decreasing pro-inflammatory cytokine compared to non-treated controls. Herein, this work elucidates the potential of NK-EVs as safe, anti-viral nanomaterials, offering a promising alternative to conventional NK cell and anti-viral therapies.

Enhancing intracellular delivery of protein kinase C beta II peptide inhibitor using myristic acid-trans-activator of transcription via N-terminus conjugation in isolated rat polymorphonuclear leukocytes

Introduction: Protein kinase C beta II (PKCβII) activation promotes polymorphonuclear (PMN) superoxide (SO) production by phosphorylating serine and threonine amino acid residues on NADPH oxidase (NOX-2). Previous studies have shown that cell permeable myristic acid-conjugated PKCβII inhibitor (myr-PKCβII-; SLNPEWNET) (20 μM) remarkably attenuated phorbol 12-myristate 13-acetate (PMA)-induced PMN SO release when compared to scrambled control peptide (myr-PKCβII- scram; WNPESLNTE), unconjugated peptides and nontreated controls by ~35%. This suggests an enhanced intracellular delivery of PKCβII-. Studies have also shown that SO release is attenuated via trans-activator of transcription-conjugated (Tat; YGRKKRRQRRR) NOX-2 inhibitor (Nox2ds-Tat) (80 μM) by ~37%. There have not been evaluations of Tat- or dual myr-Tat-conjugated PKCβII-. We hypothesize that dual myr-Tat-conjugation would enhance the intracellular delivery of PKCβII- and reduce SO release compared to myr-, Tat-, and myr-Tat-PKCβII- scram. Methods: This study focused on the effects of myr-Tat-PKCβII- on intracellular delivery compared to myr-PKCβII-, Tat -PKCβII-, and myr-Tat-PKCβII- scram, with 0.5% dimethyl sulfoxide (DMSO) vehicle as the control. Sprague-Dawley (SD) male rats (~400g) were anesthetized with isoflurane and given a 0.5% glycogen i.p. injection (16ml), and 16-18hrs later, PMNs were harvested from the peritoneal cavity and incubated for 15min at 37oC with 5μM myr-Tat-PKCβII-, myr-PKCβII-, Tat-PKCβII-, or myr-Tat-PKCβII- scram. PMN SO release was calculated spectrophotometrically by the change in absorbance at 550 nm over 390s via ferricytochrome c reduction after PMA stimulation (100nM). Data were analyzed with ANOVA Fisher’s PLSD post-hoc analysis. Results: Myr-Tat-PKCβII- (n=20, 0.338±0.024, p<0.05) and Myr-PKCβII- (n=8, 0.342±0.041, p<0.05) displayed significant attenuation of SO release by 28% and 27%, respectively, compared to 0.5% DMSO control (n=81, 0.470±0.013). Tat-PKCβII- (n=5, 0.404±0.049) showed attenuated SO release by 14% when compared to the vehicle control. Myr-Tat-PKCβII- scram (n=3, 0.542±0.081) showed an increase in SO release by 15% when compared to the vehicle control. Cell viability was > 85% in all groups. Conclusion: The results of the study suggest that intracellular delivery of PKCβII- cargo using myr-Tat dual conjugation is enhanced when compared to myr-, Tat-conjugated PKCβII-, and myr-Tat-PKCβII- scram. Future studies will utilize western blot analysis and immunohistochemistry to assess the translocation and activity of PKCβII- when conjugated with myr-Tat, myr-, or Tat- peptides. Funding: This study was funded by the National Heart, Lung & Blood Institute (1R43HL160338) SBIR phase I grant that was awarded to Young Therapeutics, LLC. Philadelphia College of Osteopathic Medicine, the Department of Biomedical Sciences, the Division of Research and the Center for Chronic Diseases of Aging. and Young Therapeutics, LLC. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Sex Dependent Exacerbation of Salt Sensitive Hypertension and Cardiac Dysfunction Is Associated With Upregulation of miRNA Targeting ADAM17 and ACE2 in the Brain

Background: The DOCA-salt model has been widely used to study salt-sensitive hypertension and we previously reported that it is associated with ADAM17-mediated ACE2 shedding in the central nervous system. However, previously reported data are mainly from male mice, and it is unclear whether female mice exhibit the same phenotypes. Objective: We aimed to compare sex specific development of salt sensitive hypertension and cardiac dysfunction and investigate miRNA regulation associated with these changes. Methods: C57 mice (male and females, n = 8 -15) underwent uninephrectomy and telemetry implantation (DSI Inc.) for blood pressure (BP) conscious recording. After baseline recording, a DOCA pellet (50 mg, 21 days, Innovative Research of America) was implanted subcutaneously and drinking water was replaced by 1% NaCl solution to induce salt sensitive hypertension. Cerebral Spinal fluid (CSF) was collected at baseline and after 3 weeks of DOCA-salt treatment for exosome miRNA sequencing (Creative Biolab). In another set of mice, cardiac function was assessed by echocardiography (Visualsonics Vevo F2) and invasive left ventricular hemodynamics (Transonic). Mortality from each group was analyzed as well. Results: Baseline BP was not different between male and female mice. Following DOCA-salt treatment for 3 weeks, BP was increased in both sexes, with higher systolic BP observed in males compared to females (active phase: 173.0 ± 19.6 vs. 154.2 ± 19.1 mmHg, p<0.05). Although ejection fraction was not changed in either male or female mice, mitral peak early diastolic filling velocity and tissue doppler showed that E/E’ was increased in both sexes compared to baselines (Male: 33.4 ± 4 vs. 26.6 ± 1.9; Female: 30.3 ± 5.0 vs. 26.4 ± 4), with a greater increase in males (25.3% vs. 14.4%). In addition, hemodynamics revealed increased left ventricular end-diastolic pressure (11.1 ± 1.9 vs. 4.5 ± 0.5 mmHg, p<0.01) and relaxation time constant Tau (6.7 ± 1.0 vs. 4.9 ± 0.5 msec, p<0.01) in DOCA-salt treated males compared to non-treated controls, with no changes shown in female mice. These data suggest worsened cardiac diastolic function in males compared to females following DOCA-salt treatment. Moreover, a 20% mortality was observed in males while no death occured in females, confirming a more severe phenotype in males. Furthermore, miRNAseq analysis of CSF exosomes showed several upregulated miRNA in males but not in females following DOCA-salt treatment. Notably, miR206 associated with increased ADAM17 activity was increased by 8-fold in males but only 3-fold n females. Conclusion: DOCA-salt treatment promotes exacerbated hypertension, impaired cardiac function and mortality in a sex dependent manner, associated with upregulation of key miRNA targeting the brain renin-angiotensin system. The changes of ADAM17 and ACE2 targeted exosome miRNAs in the central nervous system might contribute to the sex difference in the cardiovascular dysfunction phenotypes in this model. This work was supported in part by a research grant from the National Institutes of Health (HL163588). This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Evaluation of the Efficiency of some Nanoparticles and Chemical Nematicides in Controlling Root-Knot Nematodes Meloidogyne Incognita (on Eggplant)

Objectives: This study was carried out to investigate the effectiveness of some nanoparticles in inhibiting the growth of the root knot nematode. Methods: This study was carried out to investigate the effectiveness of aluminum oxide Alo-NPs and silver Ag-NPs, and chemical nematicides (Velum prime and Furadan granules), in inhibiting the growth of the root knot nematode (Meloidogyne incognita) on two different types of eggplant cultivars, Barcelona and Thuraya. Results: The result obtained indicated that chemical nematicides and nanoparticles were highly effective in lowering the nematode invasion level expressed as number of knots per root and a gall index based on a 0-5 scale. Velum prime at concentrations of 300 and 400 ppm was the most effective and gave 0.67 and 0.17 knots/root average on both eggplant cultivars, respectively. In addition, the ALO-NPs treatment reduced infection to 1.17 knots/root compared to initial infection of 37.33 knots/root. The use of Ag-NPs at the concentration of 4000 ppm reduced infection to a low average of 2.83 knots/root for both eggplant varieties. All treatments average reduced the gall index to 0.95 (cv. Barcelona) and 1.20 (cv. Thuraya) compared to 3.33 and 4.00 for the infected non-treated controls, respectively. Conclusions: Nanoparticles have a role in controlling root-knot galls as alternatives to chemical pesticides that are dangerous to the environment and humans, and reducing the number of galls on the plant indicates the inhibition of eggs and second stage juveniles (J2).