Transcriptome and ultrastructural analysis revealed the mechanism of Mercapto-palygorskite on reducing Cd content in wheat.

Large areas of crop yields in northern China have faced with cadmium (Cd) contamination problems. Mercapto-modified palygorskite (MP), as a highly efficient immobilization material, could reduce Cd absorption in wheat and alleviate its biotoxicity. However, the molecular mechanism underlying MP-mediated Cd reduction and detoxification processes in wheat is not well understood. This aim of this study was to investigate the biochemical and molecular mechanisms underlying the reduction in Cd accumulation in wheat (Triticum aestivum L.). The results showed that MP application decreased the Cd concentration by 68.91-74.32% (root) and 70.68-77.2% (shoot), and significantly increased the glutathione (GSH) and phytochelatins (PCs) contents in root and shoot. In addition, with the application of MP, the percentage of Cd in the cell walls and organelles of wheat decreased, while that of Cd in soluble components was increased. The content of Cd in all components was significantly reduced. Ultrastructural analysis revealed that MP thickened the cell wall, promoted vesicle formation in the membrane and protected the integrity of intracellular organelles in wheat. Transcriptome analysis further confirmed the above results. MP upregulated the expression of several genes (CCR, CAD COMT and SUS) involved in cell wall component biosynthesis and promoted vesicle formation on cell membranes by upregulating the expression of PLC and IPMK genes. In addition, genes related to antioxidant synthesis (PGD, glnA and GSS) and photosynthesis (Lhca, Lhcb) were altered by MP to alleviate Cd toxicity in wheat. This present work will help to more thoroughly elucidate the molecular mechanism by which wheat defends against Cd contamination under MP application and provide and important research basis for the application of this material in the future.

Influence of Foliar Zinc Application on Cadmium and Zinc Bioaccessibility in Brassica chinensis L.: In Vitro Digestion and Chemical Sequential Extraction.

Foliar zinc (Zn) application can affect the accumulation and bioaccessibility of cadmium (Cd) and Zn in crops. However, the mechanisms by which foliar Zn application influences Cd and Zn bioaccessibility remain elusive. This study examined the effects of spraying ZnSO4 and ZnNa2EDTA on bioaccessibility and chemical forms of Cd and Zn in pakchoi (Brassica chinensis L.) shoots and evaluated human health risks via pakchoi consumption. Spraying ZnSO4 reduced the concentrations of ethanol-extractable (Fethanol) and deionized water-extractable (Fd-H2O) Cd, as well as the corresponding bioaccessible Cd concentrations (20.3-66.4%) and attendant health risks of Cd, whereas spraying high-dose ZnNa2EDTA significantly increased the concentrations of both Cd forms and bioaccessible Cd. Spraying ZnSO4 and high-dose ZnNa2EDTA significantly increased the concentrations of Zn in Fethanol and Fd-H2O and the corresponding bioaccessible Zn concentrations (0.8-8.3-fold). Fethanol and Fd-H2O were the primary sources of bioaccessible Cd and Zn, contributing more than 59% of the bioaccessible Cd and Zn. These results indicate that foliar Zn application can affect Cd and Zn bioaccessibility in pakchoi mainly by modulating Cd and Zn in Fethanol and Fd-H2O. These findings provide scientific support for the development of more efficient measures to produce safe and high-quality leafy vegetables from Cd-polluted soils.

The role and transcriptomic mechanism of cell wall in the mutual antagonized effects between selenium nanoparticles and cadmium in wheat.

Selenium nanoparticles (SeNPs) has been reported as a beneficial role in alleviating cadmium (Cd) toxicity in plant. However, underlying molecular mechanisms about SeNPs reducing Cd accumulation and alleviating Cd toxicity in wheat are not well understood. A hydroponic culture was performed to evaluate Cd and Se accumulation, cell wall components, oxidative stress and antioxidative system, and transcriptomic response of wheat seedlings after SeNPs addition under Cd stress. Results showed that SeNPs application notably reduced Cd concentration in root and in shoot by 56.9% and 37.3%, respectively. Additionally, SeNPs prompted Cd distribution in root cell wall by 54.7%, and increased lignin, pectin and hemicellulose contents by regulating cell wall biosynthesis and metabolism-related genes. Further, SeNPs alleviated oxidative stress caused by Cd in wheat through signal transduction pathways. We also observed that Cd addition reduced Se accumulation by downregulating the expression level of aquaporin 7. These results indicated that SeNPs alleviated Cd toxicity and reduced Cd accumulation in wheat, which were associated with the synergetic regulation of cell wall biosynthesis pathway, uptake transporters, and antioxidative system via signaling pathways.

Variations in Cadmium and Lead Bioaccessibility in Wheat Cultivars and Their Correlations with Nutrient Components.

To reduce the health risks of exposure to Cd and Pb in wheat, a field experiment was conducted to investigate the differences in Cd and Pb bioaccessibility among the grains of 11 wheat cultivars and their relationships with the nutrient compositions of grains. The grain concentrations (Cd: 0.14-0.56 mg kg-1, Pb: 0.08-0.39 mg kg-1) and bioaccessibility (5.28-57.43% and 0.72-7.72% for Cd and Pb in the intestinal phase, respectively) of Cd and Pb differed significantly among the 11 cultivars. A safe wheat cultivar (Shannong16) with a relatively low health risk and the lowest grain Cd and Pb concentrations was selected. Ca, Mg, phytate, and methionine played key roles in affecting Cd and Pb bioaccessibility in wheat, with Ca and phytate significantly negatively correlated with Cd and Pb bioaccessibility. These findings can be used to optimize the selection strategy for safe wheat cultivars for healthy grain production in Cd-polluted farmland.

Real-world data of China: Analysis of HPV vaccine coverage and post-vaccination adverse reaction monitoring in Western Chinese provinces from 2018 to 2021.

To investigate the HPV vaccine coverage and post-vaccination adverse reactions in Gansu Province, Western China, from 2018 to 2021. Data on suspected adverse reactions to HPV vaccines were collected from the Chinese Vaccine Adverse Event Following Immunization (AEFI). Estimate the incidence rates of Common Adverse Reaction and Rare Adverse Reaction. HPV vaccine coverage among females in different age groups was calculated using data from the Gansu Provincial Immunization Information Platform. The first-dose HPV vaccine coverage rate among females aged 9 to 45 was 2.02%, with the lowest rate of less than 1% observed in females aged 9 to 14. From 2018 to 2021, the incidence rates of Common Adverse Reaction and Rare Adverse Reaction reported in females after HPV vaccination were 11.82 and 0.39 per 100,000 doses, respectively. Common Adverse Reaction included fever (5.52 per 100,000 doses), local redness and swelling (3.33 per 100,000 doses), fatigue (3.15 per 100,000 doses), headache (2.76 per 100,000 doses), as well as local induration and nausea/vomiting (1.97 per 100,000 doses). Adverse reactions mainly occurred within 1 day after vaccination, followed by 1 to 3 days after vaccination. The HPV vaccine coverage rate among females aged 9 to 14 in Gansu Province is remarkably low, and there is an urgent need to enhance vaccine coverage. From 2018 to 2021, the incidence of Adverse reaction Following Immunization HPV vaccination fell within the expected range, indicating the vaccine's safety profile.

Warm Temperature Increments Strengthen the Crosstalk between Roots and Soil in the Rhizosphere of Soybean Seedlings.

The plant rhizosphere underlies the crosstalk between plant and soil and has a crucial role in plant growth and development under various environments. We examined the effect of temperature rise on the rhizosphere environment of soybean roots to clarify the rhizosphere crosstalk between roots and soil in response to warm temperature rises in a global warming background. The in situ results of root enzyme activity revealed that soybean roots secrete ß-glucosidase, and enzyme spectrum imaging demonstrated different enzymatic activities under different temperature environments. The soil enzyme kinetics results showed that soil enzymatic activity increased with increasing temperature, and soybean rhizosphere soil enzymatic activity was higher than that of non-rhizosphere soil. Rhizosphere soil and non-rhizosphere soil showed that the dominant bacterial phylum in soybean rhizosphere soil was Acidobacteria, and the dominant bacterial genus was JG30-KF-AS9. Compared with non-rhizosphere soil, rhizosphere soil was more nutrient-rich, and root secretions provided abundant carbon sources and other nutrients for soil microorganisms in the rhizosphere. Rhizosphere microorganisms affect plant growth by influencing the decomposition of soil organic carbon. The organic carbon content of rhizosphere soil was higher than that of non-rhizosphere soil under high temperatures.