Response of Two Crop Plants, Zea mays L. and Solanum lycopersicum L., to Diclofenac and Naproxen

The paradoxical effects of beneficial bacteria on Solanum lycopersicum under Cd stress

This study investigated the complex interactions between a novel consortium and tomato seedlings under cadmium (Cd) stress. The consortium consists of two bacteria, Pseudomonas sp. HS4 and Paenarthrobacter sp. AS8, both with proven plant growth-promoting (PGP) properties, isolated from Cd hyperaccumulators. Our research highlights the paradoxical effects of these bacteria, revealing their dual role in reducing Cd uptake while simultaneously inducing oxidative stress in plants. Hydroponic experiments showed that the consortium reduced Cd accumulation in tomato shoots by 52% compared to uninoculated controls. However, this reduction was accompanied by decreased plant biomass and increased oxidative stress, with malondialdehyde (MDA) and hydrogen peroxide (H₂O₂) levels up to 80% and 160% higher, respectively, in inoculated plants. Root H₂O₂ production increased by 38% under 50 μM Cd without a corresponding rise in catalase (CAT) activity. Despite Cd exposure, the consortium promoted chlorophyll and carotenoid synthesis, restoring pigment levels to those of unstressed controls. Gene expression analysis revealed a complex impact on stress responses, with inoculation suppressing Sl1 gene expression in roots and upregulating the oxidative stress-related GR-1 gene in shoots. These findings highlight the complex and multifaceted relationship between beneficial bacteria and plant fitness under heavy metal stress, with significant implications for sustainable agriculture. The study raises new questions regarding the broader physiological and ecological impacts of applying hyperaccumulator-associated bacteria in crop management, emphasizing the necessity for deeper mechanistic insights into these interactions to fully harness their potential in improving crop resilience and productivity.

Diclofenac Interacts with Photosynthetic Apparatus: Isolated Spinach Chloroplasts and Thylakoids as a Model System

Diclofenac, often detected in environmental samples, poses a potential hazard to the aquatic environment. The present study aimed to understand the effect of this drug on photosynthetic apparatus, which is a little-known aspect of its phytotoxicity. Chloroplasts and thylakoids isolated from spinach (Spinacia oleracea) were used for this study and treated with various concentrations of diclofenac (from 125 to 4000 μM). The parameters of chlorophyll a fluorescence (the OJIP test) as measurements for both the intact chloroplasts and the thylakoid membranes revealed that isolated thylakoids showed greater sensitivity to the drug than chloroplasts. The relatively high concentration of diclofenac that is required to inhibit chloroplast and thylakoid functions suggests a narcotic effect of that drug on photosynthetic membranes, rather than a specific interaction with a particular element of the electron transport chain. Using confocal microscopy, we confirmed the degradation of the chloroplast structure after DCF treatment, which has not been previously reported in the literature. In conclusion, it can be assumed that diclofenac's action originated from a non-specific interaction with photosynthetic membranes, leading to the disruption in the function of the electron transport chain. This, in turn, decreases the efficiency of photosynthesis, transforming part of the PSII reaction centers into heat sinks and enhancing non-photochemical energy dissipation.

Multi-biomarker response of cyanobacteria Synechocystis salina and Microcystis aeruginosa to diclofenac

The cyanobacterial response to pharmaceuticals is less frequently investigated compared to green algae. Pharmaceuticals can influence not only the growth rate of cyanobacteria culture, but can also cause changes at the cellular level. The effect of diclofenac (DCF) as one of the for cyanobacteria has been rarely tested, and DCF has never been applied with cellular biomarkers. The aim of this work was to test the response of two unicellular cyanobacteria (Synechocystis salina and Microcystis aeruginosa) toward DCF (100 mg L-1) under photoautotrophic growth conditions. Such endpoints were analyzed as cells number, DCF uptake, the change in concentrations of photosynthetic pigments, the production of toxins, and chlorophyll a in vivo fluorescence. It was noted that during a 96 h exposure, cell proliferation was not impacted. Nevertheless, a biochemical response was observed. The increased production of microcystin was noted for M. aeruginosa. Due to the negligible absorption of DCF into cells, it is possible that the biochemical changes are induced by an external signal. The application of non-standard biomarkers demonstrates the effect of DCF on microorganism metabolism without a corresponding effect on biomass. The high resistance of cyanobacteria to DCF and the stimulating effect of DCF on the secretion of toxins raise concerns for environment biodiversity.

Nabumetone and flufenamic acid pose a serious risk to aquatic plants: A study with Chlamydomonas reinhardtii as a model organism

The aquatic environment is constantly under threat due to the release of numerous pollutants. Among them, pharmaceuticals constitute a huge and diverse group. Non-steroidal anti-inflammatory drugs (NSAIDs) are increasingly found in water bodies, but knowledge about their potential toxicity is still low. In particular, there is a lack of information about their influences on aquatic plants and algae. We estimated the susceptibility of the microalgae Chlamydomonas reinhardtii to nabumetone (NBT) and flufenamic acid (FFA), focusing on photosynthesis. Due to the differences in the structures of these compounds, it was assumed that these drugs would have different toxicities to the tested green algae. The hypothesis was confirmed by determining the effective concentration values, the intensity of photosynthesis, the intensity of dark respiration, the contents of photosynthetic pigments, the fluorescence of chlorophyll a in vivo (OJIP test), and cell ultrastructure analysis. Assessment of the toxicity of the NSAIDs was extended by the calculation of an integrated biomarker response index (IBR), which is a valuable tool in ecotoxicological studies. The obtained results indicate an over six times higher toxicity of NBT compared to FFA. After analysis of the chlorophyll a fluorescence in vivo, it was found that NBT inhibited electron transport beyond the PS II. FFA, unlike NBT, lowered the intensity of photosynthesis, probably transforming some reaction centers into "silent centers", which dissipate energy as heat. The IBR estimated based on photosynthetic parameters suggests that the toxic effect of FFA results mainly from photosynthesis disruption, whereas NBT significantly affects other cellular processes. No significant alteration in the ultrastructure of treated cells could be seen, except for changes in starch grain number and autophagic vacuoles that appeared in FFA-treated cells. To the best of our knowledge, this is the first work reporting the toxic effects of NBT and FFA on unicellular green algae.

Occurrence, toxicity, impact and removal of selected non-steroidal anti-inflammatory drugs (NSAIDs): A review

Non-steroidal anti-inflammatory drugs (NSAIDs) are among the most frequently used pharmaceuticals for human therapy, pet therapeutics, and veterinary feeds, enabling them to enter into water sources such as wastewater, soil and sediment, and seawater. The control of NSAIDs has led to the advent of the novel materials for treatment techniques. Herein, we review the occurrence, impact and toxicity of NSAIDs against aquatic microorganisms, plants and humans. Typical NSAIDs, e.g., ibuprofen, ketoprofen, diclofenac, naproxen and aspirin were detected at high concentrations in wastewater up to 2,747,000 ng L-1. NSAIDs in water could cause genotoxicity, endocrine disruption, locomotive disorders, body deformations, organs damage, and photosynthetic corruption. Considering treatment methods, among adsorbents for removal of NSAIDs from water, metal-organic frameworks (10.7-638 mg g-1) and advanced porous carbons (7.4-400 mg g-1) were the most robust. Therefore, these carbon-based adsorbents showed promise in efficiency for the treatment of NSAIDs.

Ambiguous changes in photosynthetic parameters of Lemna minor L. after short-term exposure to naproxen and paracetamol: Can the risk be ignored?

Non-steroidal anti-inflammatory drugs (NSAID) are recently monitored in the aquatic environment. Naproxen (NPX), paracetamol (PCT) and their transformation products can influence the biochemical and physiological processes at the sub-cellular and cellular levels taking part in the growth and development of plants. This study aimed to compare the effects of NPX and PCT, drugs with different physico-chemical properties, on the growth and photosynthetic processes in Lemna minor during a short-term (7 days) exposure. Although duckweed took up more than five times higher amount of PCT as compared to NPX (275.88 µg/g dry weight to 43.22 µg/g when treated with 10 mg/L), only NPX limited the number of new plants by 9% and 26% under 1 and 10 mg/L, respectively, and increased their dry weight (by 18% under 10 mg/L) and leaf area per plant. A considerable (by 30%) drop in the content of photosynthetic pigments under 10 mg/L treatment by both drugs did not significantly affect the efficiency of the primary processes of photosynthesis. Values of induced chlorophyll fluorescence parameters (F₀, F_V/F_M, Φ_II, and NPQ) showed just a mild stimulation by PCT and a negative effect by NPX (by up to 10%), especially on the function of photosystem II and electron transport in both intact duckweed plants and isolated chloroplasts. Lowered efficiency of Hill reaction activity (by more than 10% under 0.1 - 10 mg/L treatments) in isolated chloroplasts suspension proved the only inhibition effect of PCT to primary photosynthetic processes. In intact plants, higher treatments (0.5 - 10 mg/L) by both NPX and PCT induced an increase in RuBisCO content. The results prove that the potential effect of various drugs on plants is hard to generalise.

Potential Role of Low-Molecular-Weight Dioxolanes as Adjuvants for Glyphosate-Based Herbicides Using Photosystem II as an Early Post-Treatment Determinant

Pesticide use cannot be completely abandoned in modern agriculture. Among agrochemicals, glyphosate is one of the most popular and, at the same time, most divisive herbicide. Since the chemicalization of agriculture is detrimental, various attempts are being made to reduce it. Adjuvants-substances that increase the efficiency of foliar application-can be used to reduce the amount of herbicides used. We propose low-molecular-weight dioxolanes as adjuvants for herbicides. These compounds quickly convert to carbon dioxide and water and do not harm plants. The aim of this study was to evaluate the efficacy of RoundUp^® 360 Plus supported by three potential adjuvants: 2,2-dimethyl-1,3-dioxolane (DMD), 2,2,4-trimethyl-1,3-dioxolane (TMD), and (2,2-dimethyl-1,3-dioxan-4-yl)methanol (DDM), on a common weed species Chenopodium album L., under greenhouse conditions. Chlorophyll a fluorescence parameters and analysis of the polyphasic fluorescence (OJIP) curve, which examines changes in the photochemical efficiency of photosystem II, were used to measure plant sensitivity to glyphosate stress and verified the efficacy achieved by tested formulations. The effective dose (ED) values obtained showed that the weed tested was sensitive to reduced doses of glyphosate, with 720 mg/L needed to achieve 100% effectiveness. Compared to the glyphosate assisted with DMD, TMD, and DDM, ED was reduced by 40%, 50%, and 40%, respectively. The application of all dioxolanes at a concentration equal to 1 vol.% significantly enhanced the herbicide's effect. Our study showed that for C. album there was a correlation between the change in OJIP curve kinetics and the applied dose of glyphosate. By analyzing the discrepancies in the curves, it is possible to show the effect of different herbicide formulations with or without dioxolanes at an early stage of its action, thus minimizing the time for testing new substances as adjuvants.

Influence of Nonsteroidal Anti-Inflammatory Drugs (NSAIDs) on Photosynthetic Parameters and Secondary Metabolites of Plants from Fabaceae Family

Nonsteroidal anti-inflammatory medications (NSAIDs) are commonly used painkillers, anti-inflammatory agents, and fever reducers. They arrive in the environment from municipal wastewater and/or agriculture waste, affecting growing plants. In our study, the impact of NSAIDs, namely, diclofenac, indomethacin, naproxen, and paracetamol, on four plant species from the Fabaceae family (Cicer arietinum, Pisum sativum, Lens culinaris, and Vicia faba) was tested. The assimilation rate and stomatal conductance decreased for all plants treated with NSAIDs. Chlorophyll and carotenoid contents in the leaves of plants under stress declined by more than 15% compared with the control plants, while the flavonoids and total phenols decreased to a lesser extent. In contrast, the plants treated with NSAIDs emit terpenes and green leaf were volatile, at a level of some nmol m−2 s−1, which could influence the atmospheric reaction and ozone formation.

Uptake, Occurrence, and Effects of Nonsteroidal Anti-Inflammatory Drugs and Analgesics in Plants and Edible Crops

The plant uptake of pharmaceuticals that include nonsteroidal anti-inflammatory drugs (NSAIDs) and analgesics from contaminated environment has benefits and drawbacks. These pharmaceuticals enter plants mostly through irrigation with contaminated water and application of sewage sludge as soil fertilizer. Aquatic plants withdraw these pharmaceuticals from water through their roots. Numerous studies have observed the translocation of these pharmaceuticals from the roots into the aerial tissues. Furthermore, the occurrence of the metabolites of NSAIDs in plants has been observed. This article provides an in-depth critical review of the plant uptake of NSAIDs and analgesics, their translocation, and toxic effects on plant species. In addition, the occurrence of metabolites of NSAIDs in plants and the application of constructed wetlands using plants for remediation are reviewed. Factors that affect the plant uptake and translocation of these pharmaceuticals are examined. Gaps and future research are provided to guide forthcoming investigations on important aspects that worth explorations.