Effect of 24-epibrassinolide on reactive oxygen species and antioxidative defense systems in tall fescue plants under lead stress.

Lead is one of the most hazardous pollutants to both the environment as well as human beings. As one of the approaches to enhance phytoremediation, brassinosteroids are predicted as a potential candidate phytohormone for assisted phytoremediation. Few studies have focused on the physiological regulations of tall fescue plants (Festuca arundinacea Schreb.), a potential phytoremediation species, for its responses to applications of brassinosteroids under lead stress. Therefore, the objectives of this study were to investigate the effects of foliar application of 24-epibrassinolide, a brassinosteroids analogue, on reactive oxygen species accumulation and antioxidative defense systems of tall fescue when exposed to lead, and ultimately its potential to be used in phytoremediation. When exposed to lead (1000 mg/kg) for 80 d, decreases in shoot and root biomass of tall fescue biomass as well as chlorophyll and carotenoid productions were found. Foliar application of 24-epibrassinolide at three rates and five applications every 7 d improved the biomass of both shoots and roots, and increased the photosynthetic pigments. The improved lead tolerance in tall fescue plants after 24-epibrassinolide applications was associated with reduced H2O2 and O2.- accumulations and increased antioxidative enzyme activities including superoxide dismutase, catalase, and guaiacol peroxidase. Additionally, osmoprotectants increased and lipid peroxidation decreased. Ultimately, foliar applications of 24-epibrassinolide enhanced the lead recovery rate of tall fescue plants, proving its potential role in phytoremediation for soil contaminated with heavy metals such as lead.

Minimally invasive pyeloplasty versus open pyeloplasty for ureteropelvic junction obstruction in infants: a systematic review and meta-analysis.

Background: To compare the perioperative outcomes and success rates of minimally invasive pyeloplasty (MIP), including laparoscopic and robotic-assisted laparoscopic pyeloplasty, with open pyeloplasty (OP) in infants. Materials and Methods: In September 2022, a systematic search of PubMed, EMBASE, and the Cochrane Library databases was undertaken. The systematic review and meta-analysis were conducted in accordance with PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines, with the study registered prospectively in the PROSPERO database (CRD42022359475). Results: Eleven studies were included. Dichotomous and continuous variables were presented as odds ratios (OR) and standard mean differences (SMD), respectively, with their 95% confidence intervals (CI). Compared to OP, a longer operation time and shorter length of stay were associated with MIP (SMD: 0.96,95% CI: 0.30 to 1.62, p = 0.004, and SMD: -1.12, 95% CI: -1.82 to -0.43, p = 0.002, respectively). No significant differences were found between the MIP and OP in terms of overall postoperative complications (OR:0.84, 95% CI: 0.52 to 1.35, p = 0.47), minor complications (OR: 0.76, 95% CI: 0.40 to 1.42, p = 0.39), or major complications (OR: 1.10, 95% CI: 0.49 to 2.50, p = 0.81). In addition, a lower stent placement rate was related to MIP (OR: 0.09, 95% CI: 0.02 to 0.47, p = 0.004). There was no statistical difference for success rate between the MIP and OP (OR: 1.35, 95% CI: 0.59 to 3.07, p = 0.47). Finally, the results of subgroup analysis were consistent with the above. Conclusions: Our meta-analysis demonstrates that MIP is a feasible and safe alternative to OP for infants, presenting comparable perioperative outcomes and similar success rates, albeit requiring longer operation times. However, it is essential to consider the limitations of our study, including the inclusion of studies with small sample sizes and the combination of both prospective and retrospective research designs.

NTA-assisted mineral element and lead transportation in Eremochloa ophiuroides (Munro) Hack.

Lead (Pb) is one of the most toxic and harmful pollutants to the environment and human health. Centipedegrass (Eremochloa ophiuroides (Munro) Hack.), an excellent ground cover plant for urban plant communities, exhibits the outstanding lead tolerance and accumulation. Nitrilotriacetic acid (NTA) is an environmentally friendly chelating agent that strengthens phytoremediation. This study explored the effects of different NTA concentrations on the absorption and transportation of mineral elements and Pb in centipedegrass. Following exposure to Pb (500 µM) for 7 days in hydroponic nutrient solution, NTA increased root Mg, K, and Ca concentrations and shoot Fe, Cu, and Mg concentrations and significantly enhanced the translocation factors of mineral elements to the shoot. Although NTA notably decreased root Pb absorption and accumulation, it significantly enhanced Pb translocation factors, and the Pb TF value was the highest in the 2.0 mM NTA treatment. Furthermore, the shoot translocation of Pb and mineral elements was synergistic. NTA can support mineral element homeostasis and improve Pb translocation efficiency in centipedegrass. Regarding root radial transport, NTA (2.0 mM) significantly promoted Pb transport by the symplastic pathway under the treatments with low-temperature and metabolic inhibitors. Meanwhile, NTA increased apoplastic Pb transport at medium and high Pb concentrations (200-800 µM). NTA also enhanced the Pb radial transport efficiency in roots and thus assisted Pb translocation. The results of this study elucidate the effects of NTA on the absorption and transportation of mineral elements and Pb in plants and provide a theoretical basis for the practical application of the biodegradable chelating agent NTA in soil Pb remediation.

Melatonin-assisted phytoremediation of Pb-contaminated soil using bermudagrass.

Exogenous application of melatonin to plants is a promising approach for assisted phytoremediation of soil lead (Pb). In this study, we investigated the effects of foliar applications of melatonin to mature bermudagrass (Cynodon dactylon (L.) Pers.), a fast-growing perennial with potential as a non-hyperaccumulator plant for Pb phytoremediation. Following exposure to Pb (3000 mg kg-1) for 30 days, decreases in biomass and chlorophyll production, degradation of thylakoid membranes, reduced photosynthesis and PSII (reaction center of photosystem II) efficiency, and elevated oxidative stress were found. Foliar applications of melatonin to Pb-stressed bermudagrass mitigated these negative effects, restoring photosynthetic pigments and chloroplast ultrastructure, subsequently improving photosynthesis and photochemistry efficiency of PSII. Exogenous melatonin also eliminated the excessive accumulations of reactive oxygen species (ROS) and methylglyoxal (MG) which associated with cellular redox homeostasis by improving ascorbic acid (AsA) and reduced glutathione (GSH) contents, redox status of GSH/GSSG (oxidative glutathione), and key enzymes activities in both AsA-GSH and glyoxalase systems. Ultimately, treating bermudagrass plants with exogenous melatonin elevated biomass production and disproportionally greater Pb translocation to roots and senescent leaves. This collectively resulted in 21% greater recovery of Pb compared to Pb-stressed bermudagrass lacking melatonin application. Overall, results from this study demonstrated the beneficial roles of melatonin for improving the effectiveness of bermudagrass as a non-hyperaccumulator plant for soil Pb phytoremediation.