Unlocking hormesis and toxic effects induced by cadmium in Polygonatum cyrtonema Hua based on morphology, physiology and metabolomics.

Traditional Chinese medicine materials (TCMMs) are widely planted and used, while cadmium (Cd) is a widespread pollutant that poses a potential risk to plant growth and human health. However, studies on the influences of Cd on TCMMs have been limited. Our study aims to reveal the antioxidation-related detoxification mechanism of Polygonatum cyrtonema Hua under Cd stress based on physiology and metabolomics. The results showed that Cd0.5 (total Cd: 0.91 mg/kg; effective Cd: 0.45 mg/kg) induced hormesis on the biomass of roots, tubers and aboveground parts with increases of 22.88%, 27.12% and 17.02%, respectively, and significantly increased the flavonoids content by 57.45%. Additionally, the metabolism of caffeine, glutamine, arginine and purine was upregulated to induce hormesis in Cd0.5, which enhanced the synthesis of resistant substances such as spermidine, choline, IAA and saponins. Under Cd2 stress, choline and IAA decreased, and fatty acid metabolites (such as peanut acid and linoleic acid) and 8-hydroxyguanosine increased in response to oxidative damage, resulting in a significant biomass decrease. Our findings further reveal the metabolic process of detoxification by antioxidants and excessive Cd damage in TCMMs, deepen the understanding of detoxification mechanisms related to antioxidation, and enrich the relevant theories of hormesis induced by Cd.

Drought-resistant and water-retaining tobermorite/starch composite hydrogel for the remediation of cadmium-contaminated soil.

The objective of this work is utilizing fly ash to synthesize tobermorite (TOB) with a higher specific surface area and layered structure, and incorporating it into the starch/acrylic acid network to boost the drought resistance, water retention and heavy metal adsorption properties. The water absorption and water retention performance and cadmium adsorption characteristics of tobermorite/leftover rice-based composite hydrogel (TOB@LR-CH) were evaluated by water absorption swelling test, soil evaporation test and batch adsorption experiment. By adjusting the addition of TOB and other synthesized conditions, the swelling property (from 114.80 g/g to 322.64 g/g), water retention (71.80 %, 144 h) and Cd2+ adsorption characteristics (up to 591.36 mg/g) were significantly enhanced. Adding a moderate amount of TOB (2 wt%) provided the most uniform tobermorite dispersion during synthesis, and TOB2@LR-CH exhibited the most stable three-dimensional network and highest proportion of effective TOB. The adsorption behavior of cadmium on TOB2@LR-CH was more consistent with the pseudo-second-order kinetics and Langmuir isotherm models. Additionally, the regeneration test results displayed that the adsorption removal rate of cadmium by TOB2@LR-CH adsorbent remained stable after 5 cycles. This study demonstrates that TOB@LR-CH has good water absorption and water retention potential in arid and semi-arid soils, and also has potential application prospects in remediating Cd(II)-contaminated soil.

Selenium improves the medicinal safety and quality of Bletilla striata by promoting the fixation of cadmium in root: Pot and field experiments.

Soil cadmium (Cd) pollution poses a considerable threat to the safe production of traditional Chinese medicine (TCM) in China. The tubers of Bletilla striata, a precious TCM, are widely used to treat various ailments. However, the medicinal safety and quality of tubers are significantly affected by high Cd accumulation. While selenium (Se) is known to reduce Cd concentration in traditional crops, its impact on Cd content in medicinal parts and overall quality remains underexplored. To bridge the gap, a pot experiment and field validation were conducted to determine the effectiveness of foliar Se application. The results revealed that Se effectively counteracted Cd damage. Compared to Cd treatment alone, Se at 1.5 mg L-1 significantly decreased Cd content by 46.33 %, increased the biomass by 21.48 %, and raised the total phenolic, flavonoid, saponin, and polysaccharide contents by 46.31 %, 30.46 %, 27.08 %, and 29.01 %, respectively, in tubers. Furthermore, this study explored the mechanism of Se action. Se facilitated Cd accumulation in root cell walls and soluble fractions, enhanced the synthesis of phytochelatins (PC), and stored them in the form of PC-Cd complexes. These findings have profound implications for the cultivation of TCM, ensuring its safety, and promoting sustainable agricultural practices.

Effect of irrigation water system's distribution on rice cadmium accumulation in large mild cadmium contaminated paddy field areas of Southwest China.

There are large areas of moderately Cd-contaminated rice paddies (Cd content was less than risk intervention value) in southwest China, under natural conditions, the effect of irrigation water system's distribution on the Cd contamination in soil and rice is still less accurate. In this study, a survey of paired soil-rice (n = 1520) samples was conducted in a large paddy of about 7000 ha in southwest China that originated from the same parent material and grew with the same rice varieties. Specially, three representative characteristic regions (area A, B, C) were selected from north to south to thoroughly investigate the reasons for pollution characteristics. Background soil, irrigation water and sediment, atmospheric deposition, fertilizer were sampled to study the causes of pollution. Results showed the biological accumulation factor (BAF = C (rice Cd)/C (soil Cd)) of area C in the south reached 1.34, which was about 8 times higher than that of area A in the north. The uneven distribution of irrigation water due to geographical reasons was the most important factor leading to this pollution characteristics. The Cd content in soil of north was much higher than that in the south due to the history of Cd-contaminated irrigation and background content of Cd. During farmland formation, river impinges resulted in a gradual decrease in both Cd content and pH in the background soil from north to south. Both of historical polluters and major irrigation systems were distributed in area A. However, when sewage irrigation stopped about 30 years ago, long-term weakly alkaline irrigation increased the pH of the soil from acidic to neutral in area A. Meanwhile, flooding irrigation in area A reduced the absorption of Cd by roots compared area C where was rarely flooded during the rice planting process due to the lack of irrigation water.

CHD1L Expression Increases Tumor Progression and Acts as a Predictive Biomarker for Poor Prognosis in Pancreatic Cancer.

BACKGROUND: The chromodomain helicase/ATPase DNA binding protein 1-like gene (CHD1L) plays a key role in controlling various cellular phenomena, including immune-mediated inflammation, transformation, apoptosis, cell cycle progression, and proliferation. METHODS: This study investigated the function and clinical significance of CHD1L protein expression in pancreatic cancer (PC). We analyzed CHD1L expression in surgical specimens from 112 PC patients. The correlation between the clinical characteristics and prognosis was also determined. Futhermore, cell proliferation were measured using EDU, and a molecular mechanism of Wnt/ß-catenin pathway regulation by CHD1L was explored. RESULT: CHD1L protein expression was significantly higher in PC patients with regard to the tumor grade, stage, size, differentiation and lymph node status. Increased CHD1L protein expression was significantly associated with poor overall survival. Multivariate analyses revealed that high CHD1L expression was an independent predictive marker for the recurrence and poor prognosis of pancreatic cancer. Furthermore, silencing of CHD1L expression by RNAi effectively abolished the proliferative abilities of CHD1L in vivo and in vitro. We found that the Wnt/ß-catenin pathway contributed to the effect of CHD1L-mediated pancreatic cancer proliferation. CONCLUSION: Taken together, our data provide a novel evidence for the biological and clinical significance of CHD1L as a potential biomarker, and we demonstrate that CHD1L-Wnt/ß-catenin might be a novel pathway involved in pancreatic cancer progression.

[Adsorptive Remediation of Cr(â ¥) Contaminated Groundwater with Chemically Synthesized Schwertmannite].

Schwertmannite is usually naturally found in acidic mining wastewater and frequently used in the adsorption of heavy metal anions from water and wastewater. Schwertmannite was synthesized through a facile chemical method and utilized to remove Cr(Ⅵ) from contaminated groundwater. The kinetics, thermodynamics and isotherms, as well as the effects of environmental factors on the Schwertmannite adsorption processes were investigated. The experimental results showed that the synthesized Schwertmannite had a strong adsorption capability of Cr(Ⅵ) from aqueous solution. At the pre-set initial concentrations of Cr(Ⅵ), the Schwertmannite adsorption of Cr(Ⅵ) achieved equilibrium within 24 h, and the Lagergren's second-order model fitted the adsorption process better compared to Lagergren's first-order model and intraparticle diffusion model. Langmiur equation fitted the adsorption isotherms better than Freundlich equation. The Cr(Ⅵ) adsorption on Schwertmannite mainly involved ion exchange reaction between Cr(Ⅵ) and anions such as OH- and SO42- and surface complexation reactions. The ΔHθ and ΔGθ were 6.368 kJ·mol-1 and -1.215 kJ·mol-1, respectively, therefore the adsorption of Cr(Ⅵ) was a spontaneous and endothermic process. The removal of Cr(Ⅵ) from aqueous solution increased with increasing Schwertmannite dosage at pH=4.5. Acidic pH in the range of 4.5-6 favored Cr(Ⅵ) removal with Schwertmannite compared to that under basic conditions. Under the conditions of 5 mg·L-1of initial Cr(Ⅵ) concentration, 0.5 g·L-1 of Schwertmannite dosage, pH=6, maximum Cr(Ⅵ) removal of 93.1% was achieved and the adsorption capacity of Cr(Ⅵ) with Schwertmannite reached up to 40.4 mg·g-1. Batch tests showed that the presence of HCO3- and SO42- inhibited the adsorption of Cr(Ⅵ) while Cl- had no significant impact. Cations and natural organic matter had a pH-dependent impact on Cr(Ⅵ) removal:at pH=8 natural organic matter and cations would significantly inhibit the Cr(Ⅵ) sorption, while the impact could be neglected at weak acidic conditions (pH=6).

Cr(VI)-contaminated groundwater remediation with simulated permeable reactive barrier (PRB) filled with natural pyrite as reactive material: Environmental factors and effectiveness.

Permeable reactive barriers (PRBs) are efficient technologies for in situ remediation of contaminated groundwater, the effectiveness of which greatly depends on the reactive media filled. Natural pyrite is an iron sulfide material with a very low content of iron and sulfur, and a mining waste which is a potential material for Cr(VI) immobilization. In this study, we conducted a series of batch tests to research the effects of typical environmental factors on Cr(VI) removal and also simulated PRB filled with natural pyrite to investigate its effectiveness, in order to find a both environmentally and economically fine method for groundwater remediation. Batch tests showed that pH had the significant impact on Cr(VI) removal with an apparently higher efficiency under acidic conditions, and dissolved oxygen (DO) would inhibit Cr(VI) reduction; a relatively high initial Cr(VI) concentration would decrease the rate of Cr(VI) sorption; ionic strength and natural organic matter resulted in no significant effects on Cr(VI) removal. Column tests demonstrated that the simulated PRB with natural pyrite as the reactive media was considerably effective for removing Cr(VI) from groundwater, with a sorption capability of 0.6222 mg Cr per gram of natural pyrite at an initial Cr(VI) concentration of 10mg/L at pH 5.5 in an anoxic environment.