Straw removal or non-removal affects cadmium (Cd) accumulation in soil-rice (Oryza sativa L.) system at different ambient air Cd levels.

Despite the potential importance of the removal of contaminated straw for heavy metal output from agricultural soils, previous studies have primarily focused on the variation in the metal concentration without considering the impact input of heavy metals from atmospheric deposition. Here, rice was grown under field conditions, and, as a reference, in a deposition-free environment, and exposed to different ambient air Cd levels. Two consecutive years of pot experiments were conducted in two study areas (ZZ and LY) to examine the changes in soil physicochemical properties as well as Cd accumulation in the soil-rice (Oryza sativa L.) system in response to straw return or removal. The results showed that rice straw return enhanced the soil pH and organic matter (OM) content, but reduced the soil redox potential (Eh); and the variation in amplitude increased with number of cultivation years. After two years of cultivation, the concentrations of soil total Cd and extractable Cd in the straw-removal treatments reduced by 9.89-29.49% and 4.88-37.74%, respectively, whereas those in the straw-return treatments exhibited a slight decrease, or even an increase. This indicated that straw removal could effectively reduce the concentration and bioavailability of Cd in contaminated farmland, which was further confirmed by the results for accumulation of Cd in rice tissues. In addition, the contribution from atmospheric deposition was confirmed by the greater variation in Cd concentration in soils and rice tissues under deposition-free conditions. A major implication of our findings is that the adoption of reasonable straw-treatment measures and proper control over ambient air heavy metals can promote the remediation efficiency of Cd-contaminated fields.

Investigation of Genetic Effects of Nucleotide Variants Within the Goat PRNT Gene on Growth Performance.

Our previous study has firstly pointed that three nucleotide variants (g.-11C > T, g.117A > G, and g.149C > T) of the goat PRNT gene can significantly influence litter size. Given litter size is positively correlated with growth performance, we consider whether the PRNT gene also acts on the growth performance in goats. In this work, a correlation analysis among different litter size types and growth traits of Shaanbei white cashmere (SBWC) goats was performed, and results showed that a positive correlation did exist in our detected population (P < 0.01). Then, the association among different genotypes of three variations and goat growth performance was measured. Our results pointed to g.117A > G being significantly associated with the cannon circumference (P = 4.60E-05) while no significant effect was found between another two SNPs and growth traits after the Bonferroni's correction (P*n < 0.05). Together, this is the first report about the influence of the PRNT gene on the growth of goat and g.117A > G can be regarded as a possible DNA marker applying for MAS breeding.

Different effects of the application of urea combined with nitrification inhibitor on cadmium activity in the rice-rape rotation system.

Cadmium (Cd) is one of the most harmful and widespread pollutants in agricultural soil, where it is readily taken up by plants and threatens human health through the food chain. Nitrification inhibitors (NIs) are usually used to reduce nitrogen (N) loss in soil and increase the nitrogen use efficiency of crops. However, information regarding the Cd transfer in soil and crops system with the application of urea combined with NIs is limited. Especially, the influences of NIs on Cd availability in the rice-rape rotation are unclear. Here, we studied the pH, N speciation, and Cd activity in soils, as well as Cd accumulation in rice and rapeseed tissues that resulted after the application of dicyandiamide (DCD) and 3,4-dimethylpyrazole phosphate (DMPP) under alternating redox conditions. Rice and rape experiments appeared to represent an opposite phenomenon in the treatments of urea + NIs. Addition of NIs increased the pH of paddy soil, but decreased the pH of rapeseed soil. The treatments of urea + DCD and urea + DMPP0.5% produced a significantly lower concentration of extractable Cd in the paddy soil, and reduced the accumulation of Cd in brown rice. For rapeseed, the urea + NI treatments enhanced the Cd activity and increased the accumulation of Cd in rapeseed. It is proposed that NIs could be used to regulate N transformation in agricultural soils and inhibited Cd uptake by rice in urea fertilization. Moreover, the application of NIs combined with urea would potentially favor phytoextraction of Cd by rape, which is a ideal candidate for phytoremediation in Cd-contaminated soil.

Activation of cadmium under simulated solar illumination and its impact on the mobility of Cd in flooded soils.

In waterlogged paddy soils, cadmium (Cd) can be precipitated as cadmium sulfide (CdS) under reductive environment, thereby limiting the absorption of Cd by plants. Multiple environmental factors (such as water, pH, and Eh) played a role in the control of Cd mobility and bioavailability. In this study, we investigated the influence of the solar irradiation on the photodissolution of synthetic CdS-montmorillonite composites (CdS-M) in solution and the stability of Cd in natural soil. The release kinetic of Cd2+ showed that after the irradiation of simulated sunlight, CdS-M composites became less stable compared to the dark control. The solar irradiation seemed to enhance the release of Cd2+ from CdS significantly and continuously. Electron paramagnetic resonance (EPR) and quenching experiments confirmed that the photogenerated holes, •O2- and •OH, were possibly involved in the photo-induced release of Cd2+, while the holes was primarily responsible for the reaction. Irradiation under alkaline solution or the presence of DOM, PO43-, CO32-, and urea markedly inhibited the photodissolution process of CdS. The photo-mediated activation of Cd was further confirmed in paddy soil under natural sunlight, with a nearly threefold increase in concentration of extractable Cd during the 15 days of irradiation. This study highlights the importance of photochemical transformation of Cd in the environmental water and soil.

Chlorogenic acid inhibits apoptosis in thiram-induced tibial dyschondroplasia via intrinsic pathway.

Tibial dyschondroplasia (TD) is a common skeletal disease occurred in growth plate of fast-growing broilers. Thiram is a sort of chemical used for pesticide and fungicide. The excessive use of thiram increased the threat to animal and human health. In this study, we aimed to investigate the therapeutic mechanism of chlorogenic acid (CGA) on thiram-induced tibial dyschondroplasia. Broiler chickens were divided into three different groups, e.g., control, TD, and CGA. CGA was administrated after the induction of TD from 4th day to 7th day. Biochemical analysis was performed to detect the content of calcium (Ca) and phosphorus (P). Histological changes and degradation of extracellular matrix were observed through hematoxylin-eosin (H & E) and Masson staining. To further determine the mechanism, TUNEL staining and western blot were also performed to detect the apoptosis changes in growth plate of all groups. The results showed the disproportionation of Ca and P content and upregulation of apoptosis during the development of TD. But, after the administration of CGA, the ratio of Ca:P was upregulated, and the apoptosis was also downregulated. The current study shows the toxic effect of thiram on chickens and suggests that CGA is associated with a mechanism that plays a significant role in apoptosis induced by thiram in poultry industry.