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1.
Chemosphere ; 360: 142417, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38797210

RESUMO

Silicon (Si) effectively promote the yield of many crops, mainly due to its ability to enhance plants resistance to stress. However, how Si helps hyperaccumulators to extract Cadmium (Cd) from soil has remained unclear. In this study, Sedum alfredii Hance (S. alfredii) was used as material to study how exogenous Si affected biomass, Cd accumulation, antioxidation, cell ultrastructure, subcellular distribution and changes in gene expression after Cd exposure. The study has shown that as Si concentration increases (1, 2 mM), the shoot biomass of plants increased by 33.1%-63.6%, the Cd accumulation increased by 31.9%-96.6%, and the chlorophyll, carotenoid content, photosynthetic gas exchange parameters significantly increased. Si reduced Pro and MDA, promoted the concentrations of SOD, CAT and POD to reduce antioxidant stress damage. In addition, Si promoted GSH and PC to chelate Cd in vacuoles, repaired damaged cell ultrastructure, improved the fixation of Cd and cell wall (especially in pectin), and reduced the toxic effects of Cd. Transcriptome analysis found that genes encoding Cd detoxification, Cd absorption and transport were up-regulated by Si supplying, including photosynthetic pathways (PSB, LHCB, PSA), antioxidant defense systems (CAT, APX, CSD, RBOH), cell wall biosynthesis such as pectinesterase (PME), chelation (GST, MT, NAS, GR), Cd absorption (Nramp3, Nramp5, ZNT) and Cd transport (HMA, PCR). Our result revealed the tentative mechanism of Si promotes Cd accumulation and enhances Cd tolerance in S. alfredii, and thereby provides a solid theoretical support for the practical use of Si fertilizer in phytoextraction.


Assuntos
Cádmio , Fotossíntese , Sedum , Silício , Poluentes do Solo , Sedum/efeitos dos fármacos , Sedum/metabolismo , Sedum/genética , Cádmio/toxicidade , Cádmio/metabolismo , Silício/farmacologia , Poluentes do Solo/toxicidade , Poluentes do Solo/metabolismo , Fotossíntese/efeitos dos fármacos , Antioxidantes/metabolismo , Transcriptoma/efeitos dos fármacos , Perfilação da Expressão Gênica , Clorofila/metabolismo , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Biomassa
2.
Nanotechnology ; 34(1)2022 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-36162342

RESUMO

Perovskite quantum dots (QDs) with stable luminous properties are crucial to for the construction of corresponding light-emitting diodes (LEDs). Hybrid halide perovskite QDs, especially those contain iodine element emitting red light, usually demonstrate poor emission stability owing to the halide segregation. Moreover, red component is indispensable for the construction of white LEDs (WLEDs). Hence, it is essential to improve the luminous stability of hybrid halide perovskite QDs containing iodine element. Here, magnesium dopant and silica matrix were employed to improve the stability of hybrid halide CsPb(IBr)3QDs. Red, green and blue are three primary colors for constructing WLEDs. Therefore, silica-coated CsPbBr3QDs emitting green light were also synthesized. The fabricated silica-coated Mn:CsPb(IBr)3/PMMA film delivered good emission stability during a 42 d observation period, exhibiting the improved stability compared with the corresponding Mn:CsPb(IBr)3QDs in solution. WLEDs were fabricated by integrating the mixture of silica-coated Mn:CsPb(IBr)3QDs, silica-coated CsPbBr3QDs and silicon sealant with a blue-emission LED chip. The as fabricated device exhibited a longer lifetime to be lit than that of those reported previously. During the 36 d observation period for the as fabricated device, the red emission from the silica-coated Mn:CsPb(IBr)3QDs experienced a peak-emission shift of 34 nm, which is much less than that in Mn:CsPb(IBr)3QDs solution. Their overall intensity downtrend combined the peak-emission shift are responsible for the spectrum shape change, so as to the fluctuation of color correlated temperature and color rendering index. Our study provides a good starting point for the further improvement of the stability of the hybrid halide perovskites QDs and the corresponding light-emitting devices. With deep studies on the synthesis method and luminous mechanism for hybrid halide CsPb(IBr)3QDs, red-emission perovskite QDs with satisfied properties are expected to be obtained.

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