More Like this

1. Soil-derived fulvic acid and root exudates, modified by soil bacteria, alter CuO nanoparticle-induced root stunting of wheat via Cu complexation

   https://doi.org/10.1039/c9en00728h  

   Hortin, J. M.; Anderson, A. J.; Britt, D. W.; Jacobson, A. R.; McLean, J. E. (December 2019, Environmental Science: Nano)

   CuO nanoparticles (NPs) are explored as fungicides and fertilizers, and are increasingly likely to be applied to agricultural soils. Consequently, interactions of CuO NPs with soil pore water (SPW) components, plants, and microbes must be understood. These experiments examined whether dissolved natural organic matter (DNOM) from SPW, or root/bacterial exudates, changed wheat ( Triticum aestivum L. v. Deloris) responses to 100 mg kg −1 (Cu/sand) as CuO NPs. Seedlings were grown in sand with 3.34 mM Ca(NO 3 ) 2 or one of three SPWs, differing in DNOM concentration and composition. At 10 days post-germination, CuO NPs stunted roots by 59% in the 3.34 mM Ca(NO 3 ) 2 and 26–35% in the three SPWs compared to plants grown without NPs. Malate, citrate, gluconate, and 2′-deoxymugineic acid (DMA), were elevated 1.3 to 5-fold in the rhizosphere with CuO NPs present. Cu was bioavailable through metallo-organic complexes, including Cu–DMA and Cu–gluconate. Fulvic acid in SPWs mitigated CuO NP-induced wheat root shortening. Pseudomonas chlororaphis O6 eliminated malate and citrate in the rhizospheres, reduced rhizosphere dissolved Cu ∼18–66%, and reduced root Cu 39% across all SPWs while enhancing root stunting ∼17% more across all SPWs than non-inoculated wheat grown with CuO NPs. Thus, both SPW components and root microbial colonization influenced wheat responses to CuO NPs. These interactions are likely in agricultural soils with additional processes, such as ion sorption, to influence CuO NP phytotoxicity, highlighting the importance of considering not just the target plant, but soil properties and associated microbiomes when evaluating impacts of NPs in agricultural usage. 

   more » « less
2. A Review of Metal and Metal-Oxide Nanoparticle Coating Technologies to Inhibit Agglomeration and Increase Bioactivity for Agricultural Applications

   https://doi.org/10.3390/agronomy10071018  

   Cartwright, Anthony; Jackson, Kyle; Morgan, Christina; Anderson, Anne; Britt, David W. (July 2020, Agronomy)

   null (Ed.)

   Coatings offer a means to control nanoparticle (NP) size, regulate dissolution, and mitigate runoff when added to crops through soil. Simultaneously, coatings can enhance particle binding to plants and provide an additional source of nutrients, making them a valuable component to existing nanoparticle delivery systems. Here, the surface functionalization of metal and metal-oxide nanoparticles to inhibit aggregation and preserve smaller agglomerate sizes for enhanced transport to the rooting zone and improved uptake in plants is reviewed. Coatings are classified by type and by their efficacy to mitigate agglomeration in soils with variable pH, ionic concentration, and natural organic matter profiles. Varying degrees of success have been reported using a range of different polymers, biomolecules, and inorganic surface coatings. Advances in zwitterionic coatings show the best results for maintaining nanoparticle stability in solutions even under high salinity and temperature conditions, whereas coating by the soil component humic acid may show additional benefits such as promoting dissolution and enhancing bioavailability in soils. Pre-tuning of NP surface properties through exposure to select natural organic matter, microbial products, and other biopolymers may yield more cost-effective nonagglomerating metal/metal-oxide NPs for soil applications in agriculture. 

   more » « less
3. Absence of Nanoparticle-Induced Drought Tolerance in Nutrient Sufficient Wheat Seedlings

   https://doi.org/10.1021/acs.est.1c00453  

   Potter, Matthew; Deakin, Justin; Cartwright, Anthony; Hortin, Joshua; Sparks, Dakota; Anderson, Anne J.; McLean, Joan E.; Jacobson, Astrid; Britt, David W. (May 2021, Environmental Science & Technology)

   null (Ed.)

   Strategies to reduce crop losses due to drought are needed as climate variability affects agricultural productivity. Wheat (Triticum aestivum var. Juniper) growth in a nutrient-sufficient, solid growth matrix containing varied doses of CuO, ZnO, and SiO2 nanoparticles (NPs) was used to evaluate NP mitigation of drought stress. NP amendments were at fertilizer levels, with maxima of 30 Cu, 20 Zn, and 200 Si (mg metal/kg matrix). Seeds of this drought-tolerant cultivar were inoculated with Pseudomonas chlororaphis O6 (PcO6) to provide a protective root microbiome. An 8 day drought imposed on 14 day-old wheat seedlings decreased shoot and root mass, shoot water content, and the quantum yield of photosystem II when compared to watered plants. PcO6 root colonization was not impaired by drought or NPs. A dose-dependent increase in the Cu, Zn, and Si from the NPs was observed from analysis of the rhizosphere solution, and this process was not affected by drought. Consequently, fertilizer concentrations of the NPs did not further improve drought tolerance in wheat seedlings under the growth conditions of adequate mineral nutrition and the presence of a beneficial microbiome. These findings suggest that potential NP benefits in promoting plant drought tolerance occur only under certain environmental conditions. 

   more » « less
4. Pesticide presence and distribution in a cold region agricultural basin

   https://doi.org/10.1016/j.scitotenv.2025.180477  

   Whitten, Jeffrey; Mahmood, Taufique H; Jeannotte, Tyson L (October 2025, Science of The Total Environment)

   Variable precipitation patterns in cold climates, worsening due to climate change, raise concerns regarding pesticide mobility and mixture toxicity, potentially amplifying drinking water contamination and adverse effects on aquatic and subsurface ecosystems. Currently, there is limited understanding of pesticide transport in cold-region watersheds characterized by alternating dry and wet conditions. This study investigates pesticide occurrence and distribution in the Mauvais Coulee Basin (MCB) across three hydrologically distinct years (2021–2023), using biannual sampling of streams and groundwater following snowmelt and major rainfall events. We hypothesized that cold-region hydroclimate influenced pesticide concentration, predicting lower concentrations during wet years and elevated levels during dry years. We also hypothesized that soil clay and organic matter influence vertical transport. Cumulative pesticide concentration was 7.87 μg/L across 102 analytes. Herbicides and their metabolites exhibited seasonal spikes, particularly Pyrasulfotole (0.22 μg/L), Metolachlor ESA (0.19 μg/L), 2,4-D (0.35 μg/L), and Tebuconazole (0.35 μg/L), while neonicotinoid detections were limited. A Random Forest Regression (RFR) model examining 2,4-D concentrations in groundwater against soil and well characteristics such as sand and clay content, pH, organic matter, and bulk density, identified pH (24.6 % importance) and sand percentage (21.1 % importance) as the primary influences. Compared with sandy, shallow aquifer systems reported elsewhere, mobility of neonicotinoids was limited due to clay content and deeper groundwater. Snowmelt volume and post-thaw rainfall alternately diluted (wet year) or concentrated (dry year) pesticide loads. Water pH and sand content, indicated by RFR modeling, governed leaching of 2,4-D to groundwater; clay and organic matter were not the primary influences. 

   more » « less
5. Metabolomic Response of Early-Stage Wheat (Triticum aestivum) to Surfactant-Aided Foliar Application of Copper Hydroxide and Molybdenum Trioxide Nanoparticles

   https://doi.org/10.3390/nano11113073  

   Huang, Xiangning; Keller, Arturo A. (November 2021, Nanomaterials)

   Surfactants are commonly used in foliar applications to enhance interactions of active ingredients with plant leaves. We employed metabolomics to understand the effects of TritonTM X-100 surfactant (SA) and nanomaterials (NMs) on wheat (Triticum aestivum) at the molecular level. Leaves of three-week-old wheat seedlings were exposed to deionized water (DI), surfactant solution (SA), NMs-surfactant suspensions (Cu(OH)2 NMs and MoO3 NMs), and ionic-surfactant solutions (Cu IONs and Mo IONs). Wheat leaves and roots were evaluated via physiological, nutrient distribution, and targeted metabolomics analyses. SA had no impact on plant physiological parameters, however, 30+ dysregulated metabolites and 15+ perturbed metabolomic pathways were identified in wheat leaves and roots. Cu(OH)2 NMs resulted in an accumulation of 649.8 μg/g Cu in leaves; even with minimal Cu translocation, levels of 27 metabolites were significantly changed in roots. Due to the low dissolution of Cu(OH)2 NMs in SA, the low concentration of Cu IONs induced minimal plant response. In contrast, given the substantial dissolution of MoO3 NMs (35.8%), the corresponding high levels of Mo IONs resulted in significant metabolite reprogramming (30+ metabolites dysregulated). Aspartic acid, proline, chlorogenic acid, adenosine, ascorbic acid, phenylalanine, and lysine were significantly upregulated for MoO3 NMs, yet downregulated under Mo IONs condition. Surprisingly, Cu(OH)2 NMs stimulated wheat plant tissues more than MoO3 NMs. The glyoxylate/dicarboxylate metabolism (in leaves) and valine/leucine/isoleucine biosynthesis (in roots) uniquely responded to Cu(OH)2 NMs. Findings from this study provide novel insights on the use of surfactants to enhance the foliar application of nanoagrochemicals. 

   more » « less