Peicheng Huang,Weichun Yang,Qingzhu Li,Qi Liao,Mengying Si,Meiqing Shi,Zhihui Yang
In this study, a novel slightly-soluble selenium (Se) fertilizer (SSF) was successfully applied to address the problems of Cd pollution in paddy soil and rice, and Se deficiency in human beings. The pot and field experiments showed that Cd content in the rice grains was reduced by 48.4%–82.89% and Se content was increased nearly by 30-fold comparing the control group. The application of SSF increased the soil pH and significantly reduced the DGT-extracted Cd in the soil. Moreover, DCB-extractable Fe content on the surface of roots was prompt by SSF, which formed a physical barrier, namely iron plaque (IP), to inhibit Cd translocation to the above-ground tissues of the rice plants. The Cd content in the IP was also decreased before the filling period, possibly contributing to the reduction in major Cd accumulation in the rice grains. In addition, the continuous Se increase and Cd reduction in the IP by the SSF gradually exceeded that of water-soluble Se during the three periods of rice plant growth. This suggests that SSF has high potential to be an effective Se fertilizer for inhibiting Cd uptake and enriching Se in rice.
Tobacco (Nicotiana tabacum L.) is well-known as an economic crop whose quality is evaluated according to its aroma quality. Researchers have found that selenium application can increase the aroma quality of tobacco, but until now, its mechanism is still unclear. So a field experiment was conducted to investigate the regulatory effect of the trace element selenium on enhancing aroma substances in flue-cured tobacco leaves. We compared selenium content, aroma precursors, non-volatile organic acids (NVOAs) content, and neutral aroma substances in tobacco upper leaves that applying three selenium fertilizer types (sodium selenite, organic selenium and nano-selenium) with three levels of pure selenium application rates (5.24 g·hm-2, 10.48 g·hm-2, and 15.72 g·hm-2) through foliar spraying. The results showed that the neutral aroma substances and NVOAs content were significantly increased. Metabolomics analysis of NVOAs showed that biosynthesis of phenylpropanoids pathway was significantly enriched. This indicates that selenium application may be able to regulate the accumulation of phenylpropane degradation products by regulating these NVOAs involved in the biosynthesis of phenylpropanoids pathway. Selenium content was significantly positively correlated with phenylpropane degradation products, NVOAs content, and phenolic compounds, while pyruvate was significantly down-regulated in each selenium application treatment. Therefore, it was speculated that selenium application could enhance the conversion of pyruvate into the biosynthesis of phenylpropanoids pathway. In summary, spraying organic selenium at 5.24–15.72 g·hm-2 or nano-selenium at 5.24–10.48 g·hm-2 could provide a suitable strategy for improving tobacco aroma quality.
The application of Se fertilizers could promote plant growth and enhance Se contents of crops. However, traditional Se fertilizer tended to be lost with rainwater and caused Se pollution. Thus, it was necessary to develop a smart nanosystem to control Se fertilizer release. In this work, an anion-responsive nanosystem was prepared using polyethylenimine modified hollow/mesoporous carbon nanoparticles (PHMCN), and selenate could be effectively loaded into PHMCN (the highest loading capacity: 389 mg/g) by electrostatic attraction . The release of Se from this nanosystem could be sensitively triggered using PO 4 3− , CO 3 2− , and OH − as the model anions by ion exchange, and the release amount of Se was dependent on the concentration and valence of anions, so that the Se loss could be significantly reduced and the yield and Se content of vegetables increased. This work provides a promising strategy for obtaining Se-enriched vegetables and reducing Se pollution.
危险品化学品经营许可证（带存储）