Soil carbon (C) sequestration, as an ecosystem property, may be strongly influenced by invasive plants capable of depositing disproportionately high quantities of chemically distinct litter that ...disrupt ecosystem processes. However, a mechanistic understanding of the processes that regulate soil C storage in invaded ecosystems remains surprisingly elusive. Here, we studied the impact of the invasion of two noxious nonnative species, Polygonum cuspidatum, which produces recalcitrant litter, and Pueraria lobata, which produces labile litter, on the quantity, molecular composition, and stability of C in the soils they invade. Compared with an adjacent noninvaded old‐field, P. cuspidatum‐invaded soils exhibited a 26% increase in C, partially through selective preservation of plant polymers. Despite receiving a 22% higher litter input, P. lobata‐invaded Pinus stands exhibited a 28% decrease in soil C and a twofold decrease in plant biomarkers, indicating microbial priming of native soil C. The stability of C exhibited an opposite trend: the proportion of C that was resistant to oxidation was 21% lower in P. cuspidatum‐invaded soils and 50% higher in P. lobata‐invaded soils. Our results highlight the capacity of invasive plants to feed back to climate change by destabilizing native soil C stocks and indicate that environments that promote the biochemical decomposition of plant litter would enhance the long‐term storage of soil C. Further, our study highlights the concurrent influence of dominant plant species on both selective preservation and humification of soil organic matter.
The emerging classes of perfluorinated alkyl substances (PFAS) (e.g., Perfluorobutanoic acid (PFBA), perfluorobutane sulfonic acid (PFBS), GenX, ADONA, and F–53B) are persistent and recalcitrant to ...removal by conventional treatment techniques. Herein, we report on poly (N-3-(dimethylamino)propylacrylamide, methyl chloride quaternary, DMAPAA-Q) hydrogel matrix as an effective sorbent for sequestering PFAS from different water matrices. The selective removal of 16 PFAS from different classes using DMAPAA-Q polymer was confirmed in surface waters and treated wastewater at environmentally relevant concentration (i.e., <1000 ng/L). The results showed fast removal kinetics with equilibrium time of 60–120 min and a higher removal of sulfonated than carboxylic PFAS, regardless of their chain lengths. These observations were in agreement with adsorption energy calculations of short- and long-chain PFAS on poly DMAPAA-Q hydrogel using density functional theory (DFT). No desorption was observed when the experimental time was extended to 24 h, which gives an added advantage of poly DMAPAA-Q hydrogel over previously reported adsorbents in the literature. In addition, the removal efficiency was not affected under a varying pH range of 4–10. The impact of background anions on PFAS removal by poly DMAPAA-Q hydrogel was tested and found to follow an order of SO42− > Cl− > NO3−. The performance of poly DMAPAA-Q hydrogel was maintained in six consecutive adsorption/regeneration cycles to remove PFAS. The unique fast kinetics and high adsorption activity of poly DMAPAA-Q hydrogel towards PFAS exhibits a great potential for being a promising material for PFAS control.
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•The cationic polymer show fast removal of short and long chain PFAS and GenX.•The polymer maintains high removal at pH range of 4–10.•Selective removal of 16 PFAS was confirmed in surface water and wastewaters.•The performance was maintained in ten consecutive adsorption/regeneration cycles.•Calculated adsorption energies by DFT matched the experimental results.
Plant uptake and metabolism of pesticides are complex and dynamic processes, which contribute to the overall toxicity of the pesticides. We investigated the metabolic fate of cyantraniliprole, a new ...diamide class of insecticide, during various growth stages of tomato. Cyantraniliprole was the major residue in leaves, flowers, and fruits, with the relative metabolite-to-parent ratios maintained at < 10% up to 28 days after treatment (DAT). Mature leaves contained consistently higher residues of cyantraniliprole than young leaves throughout the study. Flowers contained the highest cyantraniliprole residues up to 21 DAT, then gradually decreased. Immature green fruits had the highest cyantraniliprole residues (5.3 ± 0.7 ng/g; 42 DAT), and decreased toward red ripening stages (1.4 ± 0.2 ng/g; 84 DAT). Metabolism of cyantraniliprole primarily occurred in the foliage, where 21 metabolites were tentatively identified. Flowers and fruits contained 14 and four of these metabolites, respectively. Major transformation pathways were characterized by ring closure, followed by N-demethylation, and glycosylation. Additionally, plant metabolism of cyantraniliprole was also associated with several minor phase-I, phase-II, and breakdown metabolites. The occurrence of these metabolites in plants varied as a function of tissue types and their developmental stages. Our study highlights a tissue-specific biotransformation and accumulation of metabolites of cyantraniliprole in tomato.
Unlike quantitative changes, the compositional changes of plant phenolics and changes in their tissue association as influenced by the nutrient supply are less well understood. We evaluated the ...quantity, composition, and tissue association of phenolics in leaves of two
cultivars in response to different levels of nitrogen (N) fertilization using global metabolomic approaches. Influence of N supply on phenolic content in both cultivars was similar, but the magnitude of this response was compound specific. Ellagitannins, the most abundant class of phenolic oligomers, were less responsive to the applied N treatments, whereas proanthocyanidins, the less abundant class of phenolic oligomers, exhibited higher fold change. Within mono-phenolics, the hydroxycinnamates were more abundant but showed lower fold change than the hydroxybenzoates. Among flavonoids, the hydroxylated flavonols showed higher abundances than the flavones, with a preferential accumulation of dihydroxylated flavonol at lower N levels. Furthermore, glycosylated flavonols were higher than the acylated forms. The extractable fraction of phenolics was more influenced by the N treatment than the fiber-bound fraction. The extensive compositional modification of phenolics and a greater response of non-bound fractions in response to N rates highlight the potential to use precise management of N supply as an effective strategy to enhance the bioactive compounds in crops.
Meat and bone meal (MBM) is a byproduct of the rendering industry and is considered an excellent potential organic fertilizer due to its balanced availability of nutrients. However, rapid nutrient ...mineralization of the MBM that is less synchronized with crop demand, could lead to significant nutrient losses, necessitating measures to modify the mineralization rates of MBM. Here we tested the influence of two natural nitrification inhibitors (NIs; neem cake and karanja cake) on the mineralization of carbon (C), nitrogen (N), and phosphorus (P) from MBM, the associated soil potential enzymatic activity, microbial abundance and broad composition and the influence of these process on plant growth. MBM mineralized quickly, with 35% mineralization of the applied N within the first 5 days of incubation. NIs reduced nitrification rate of MBM by ~ 40% and increased the retention of NH
4
+
(~ 35%) in soil compared with MBM only. Soil CO
2
respiration, potential enzymatic activity and microbial abundance were similar in the MBM with and without NIs, suggesting a low negative effect of NIs on the microbial growth and functionality. MBM exhibits a slow P mineralization rate, with an increase in soil available P was observed only at later sampling points (36 days after incubation) with solubilization of a fraction of Ca-P. P mineralization rates were similar between the MBM with and without NIs. MBM with and without NIs was equally effective in maintaining the plant growth and biomass, which were similar to inorganic fertilizers. Our study suggests that MBM blended with NIs could increase the crop nutrient use efficiency via lowering N losses, while improving soil microbiological health.
Together, climate and litter quality strongly regulate decomposition rates. Although these two factors and their interaction have been studied across species in continent-scale experiments, few ...researchers have studied how labile and recalcitrant compounds interact to influence decomposition, or the climate sensitivity of decomposition, within a litter type.
Over a period of 3 yr, we studied the effects of warming and altered precipitation on mass loss and compound-specific decomposition using two litter types that possessed similar heteropolymer chemistry, but different proportions of labile and recalcitrant compounds.
Climate treatments immediately affected the mass loss of the more recalcitrant litter, but affected the more labile litter only after 2 yr. After 3 yr, although both litter types had lost similar amounts of mass, warming (c. 4°C) and supplemental precipitation (150% of ambient) together accelerated the degradation of alkyl-carbon and lignin only in the more recalcitrant litter, highlighting the role of initial litter quality in determining whether the chemistry of litter residues converges or diverges under different climates. Our finding that labile compounds in litter reduce the climate sensitivity of mass loss and the decomposition of recalcitrant matrix is novel.
Our results highlight the potential for litter quality to regulate the effect of climatic changes on the sequestration of litter-derived carbon.
Summary
Introduced, invasive plants can alter local soil chemistry and microbial communities, but the underlying mechanisms and extent of these changes are largely unknown. Based on characteristics ...associated with invasiveness in plants, it was hypothesized that introduced species that produce large amounts of litter with distinctive secondary compounds can a) alter the chemistry of both extractable and bulk carbon in the soil, b) shift microbial communities towards microbes better able to metabolize the compounds in the litter and c) cause soil carbon chemistry and microbial communities to shift to relatively uniform, novel states at multiple sites.
Composition of phenolics in senescent tissues (leaves and roots) of Polygonum cuspidatum was compared to the composition of extractable phenolics and non‐extractable bulk organic carbon in soils under and adjacent to large, long‐established stands of P. cuspidatum at four sites in the eastern U.S. Rates of degradation of phenolics, activities of enzymes associated with the breakdown of phenolics and shifts in microbial community composition were also measured at the sites.
Soils under P. cuspidatum stands contained twice as much phenolics as adjacent soils, but the composition of phenolics differed greatly between soils under stands and senescent tissues of P. cuspidatum. Flavonoids and proanthocyanidins constituted >90% of the identified phenolics in P. cuspidatum tissues, whereas monophenolic compounds accounted for >90% of the phenolics in soils under stands. Soils under and adjacent to stands also exhibited distinctive compositions of relatively persistent bulk organic carbon; composition differed less between soils under stands at different sites than between soils under and adjacent to stands at the same site.
Soils under P. cuspidatum had 2·8 times greater abundance of fungi than soils adjacent to stands, and fungal markers showed clear separation of soils under and adjacent to P. cuspidatum. However, the potential activity of enzymes that degrade polyphenols was lower in soils under stands. Exogenously applied, chemically complex polyphenols persisted in both P. cuspidatum‐invaded and adjacent non‐invaded soils, whereas less complex compounds rapidly disappeared from both soils.
Synthesis. Results suggest that interactions between plant inputs, abiotic reactions and biotic transformations may create and maintain new states in invaded soils that are chemically and biologically less diverse. In the case of polyphenol‐rich, fast‐growing invasive species, these interactions may alter the composition of bulk soil organic matter that has relatively slower turnover rates, resulting in legacy effects. Restoration could thus require, not just removal of the species, but also post‐removal interventions such as soil amendments.
Lay Summary
Per- and polyfluoroalkyl substances (PFAS) are ubiquitous in many consumer products and present serious environmental challenges due to their persistent nature. Currently, conventional water ...treatment methods fail to remove PFAS, and other newly proposed materials/techniques face challenges when employed under realistic conditions. This study reports on poly(ethylenimine)-functionalized cellulose microcrystals (PEI-f-CMC) that showed a near-instant and high removal of PFAS under concentrations relevant to their actual occurrence in the natural environment (i.e., <1000 ng/L). The selective removal efficiency of 22 PFAS from different classes (i.e., legacy carboxylic and sulfonated PFAS, emerging carboxylic and sulfonated PFAS, and PFAS-precursors) using PEI-f-CMC was confirmed in lake water as well as solutions codosed with two additional types of natural organic matter. The performance of PEI-f-CMC was maintained in eight consecutive adsorption/regeneration cycles to remove PFAS. The PEI-f-CMC with its unique fast kinetics and high adsorption activity toward PFAS exhibits a great potential for being a promising alternative adsorbent for PFAS control.
This work investigates the uptake and root-shoot transport of plutonium (Pu) and iron (Fe) in corn ( Zea mays ) to gain insight into the Pu uptake pathway. Plutonium has no known biological function ...in plants yet may feasibly enter plants through the uptake pathway used by Fe (an essential nutrient), as these two elements have similar chemical properties. A series of experiments was conducted in which two hydroponically grown corn strains (one normal and one deficient in the transporter protein for Fe) were exposed to varying concentrations of complexed Pu and Fe. Results suggest that while Fe did inhibit Pu uptake to a certain extent, Pu was able to use alternative uptake pathways. In a 10 ppb Pu:1 ppb Fe hydroponic solution, all shoots had detectable shoot Pu concentrations compared to only 22% of plants when the Fe concentration was raised to 10 ppb. While root Pu accumulation was reduced for the corn strain deficient in the Fe transporter protein at lower Pu media concentrations, there were no differences at higher Pu concentrations, signifying the existence of substitute transport routes. A comparison of citrate and deferoxamine B (DFOB) ligand influence found that Pu complexed with DFOB remained in the roots of the plant, while movement of Pu into the shoots of the plant was more prevalent with the Pu-citrate complex. This study advances understanding of the behavior and mobility of Pu in the terrestrial environment and specifically the interactions between Pu and an essential nutrient in a common crop species.
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