Cloning and overexpression of the ascorbate peroxidase gene from the yam (Dioscorea alata) enhances chilling and flood tolerance in transgenic Arabidopsis.

Minghuai 1 (MH1) is a yam (Dioscorea alata) cultivar with high tolerance to flooding but sensitivity to chilling. MH1 responded differently to chilling and flooding according to various physiological parameters and antioxidant enzymes. Flooding led to an increase in ascorbate peroxidase (APX) activity in both roots and leaves, while chilling did not affect APX activity. The full length DaAPX ORF sequence from MH1 (750 bp) was then cloned. Phylogenetic analysis showed that plant cytosolic APXs into four major clusters and DaAPX was closely related to Oncidium. The DaAPX gene driven by a 35S promoter was transferred into Arabidopsis. The gene expression and enzyme activity of APX in the DaAPX transgenic lines 1-3 were significantly higher than in wild type (WT) plants. Compared to WT plants, seedling growth characteristics were significantly better in all transgenic lines under chilling, flooding, and oxidative stresses, indicating that the overexpression of DaAPX in Arabidopsis enhanced tolerance to several abiotic stresses. MH1 plants supplied with H2O2 presented an increase in the activity of APX leading to enhanced tolerance to chilling. Functional characterization of the APX gene should improve our understanding of the chilling- and flood-response mechanism in the yam.

Punicalagin Ameliorates Diabetic Liver Injury by Inhibiting Pyroptosis and Promoting Autophagy via Modulation of the FoxO1/TXNIP Signaling Pathway.

Diabetic liver injury (DLI) is one of the complications of diabetes mellitus, which seriously jeopardizes human health. Punicalagin (PU), a polyphenolic compound mainly found in pomegranate peel, has been shown to ameliorate metabolic diseases such as DLI, and the mechanism needs to be further explored. In this study, a HFD/STZ-induced diabetic mouse model is established to investigate the effect and mechanism of PU on DLI. The results show that PU intervention significantly improves liver histology and serum biochemical abnormalities in diabetic mice, significantly inhibits the expression of pyroptosis-related proteins such as NLRP3, Caspase1, IL-1ß, and GSDMD in the liver of diabetic mice, and up-regulated the expression of autophagy-related proteins. Meanwhile, PU treatment significantly increases FoxO1 protein expression and inhibits TXNIP protein expression in the liver of diabetic mice. The above results are further verified in the HepG2 cell injury model induced by high glucose. AS1842856 is a FoxO1 specific inhibitor. The intervention of AS1842856 combined with PU reverses the regulatory effects of PU on pyroptosis and autophagy in HepG2 cells. In conclusion, this study demonstrates that PU may inhibit pyroptosis and upregulate autophagy by regulating FoxO1/TXNIP signaling, thereby alleviating DLI.

Induction of Hibernation and Changes in Physiological and Metabolic Indices in Pelodiscus sinensis.

Pelodiscus sinensis (P. sinensis) is a commonly cultivated turtle species with a habit of hibernation. To study the changes in histone expression and methylation of P. sinensis during hibernation induction, a model was established by artificial induction. Physiological and metabolic indices were measured, and the expression and localization of histone (H1, H2A, H2B, H3, and H4) and methylation-related genes (ASH2L, KMT2A, KMT2E, KDM1A, KDM1B, and KDM5A) were measured by quantitative PCR, immunohistochemistry, and Western blot analysis. The results indicated that the metabolism, antioxidation index, and relative expression of histone methyltransferase were significantly decreased (p < 0.05), whereas the activity and expression of histone demethyltransferase were significantly increased (p < 0.05). Although our results showed significant changes in physiological and gene expression after hibernation induction, we could not confirm that P. sinensis entered deep hibernation. Therefore, for the state after cooling-induced hibernation, cold torpor might be a more accurate description. The results indicate that the P. sinensis can enter cold torpor through artificial induction, and the expression of histones may promote gene transcription. Unlike histones expressed under normal conditions, histone methylation may activate gene transcription during hibernation induction. Western blot analysis revealed that the ASH2L and KDM5A proteins were differentially expressed in the testis at different months (p < 0.05), which may perform a role in regulating gene transcription. The immunohistochemical localization of ASH2L and KDM5A in spermatogonia and spermatozoa suggests that ASH2L and KDM5A may perform a role in mitosis and meiosis. In conclusion, this study is the first to report changes in histone-related genes in reptiles, which provides insight for further studies on the physiological metabolism and histone methylation regulation of P. sinensis during the hibernation induction and hibernation period.

Construction 0D/2D heterojunction by highly dispersed Ag2S quantum dots (QDs) loaded on the g-C3N4 nanosheets for photocatalytic hydrogen evolution.

In recent years, the use of quantum dots (QDs) cocatalysts to improve the hydrogen evolution activity from the water splitting of photocatalysts has become a popular research topic. Herein, we successfully prepared a novel 0 dimension/2 dimension (0D/2D) heterojunction nanocomposite (denoted Ag2S quantum dots (QDs)/g-C3N4) with excellent photocatalytic performance by anchoring the Ag2S QDs cocatalyst on the surface of g-C3N4 through a self-assembly strategy. Ag2S QDs with an average particle size of approximately 5.8 nm were uniformly and tightly modified on g-C3N4. The Ag2S QDs/g-C3N4 composite with 0.5 wt% Ag2S QDs loading achieved the highest hydrogen evolution rate of 471.1 µmol·g-1·h-1 with an apparent quantum efficiency (AQE) of 1.48% at 405 nm. Such remarkable hydrogen evolution activity far exceeded that of undoped g-C3N4 and Ag2S nanoparticles (NPs)/g-C3N4. Moreover, it was 2.04 times the activity of Pt/g-C3N4 with Pt as the cocatalyst. The enhanced photocatalytic performance was attributed to the energy band broadening of Ag2S QDs caused by the quantum size effect and the convenient and effective charge transfer between g-C3N4 and Ag2S QDs cocatalysts. The mechanism underlying the enhanced photocatalytic H2 evolution activity was further proposed. This study demonstrates that semiconductor-based quantum dots are strong candidates for excellent cocatalysts in photocatalysis.

State-of-the-art recent progress in MXene-based photocatalysts: a comprehensive review.

Recently, the emerging two-dimensional material MXene enjoys a high reputation due to its fascinating characteristics and shines in various research fields. Among them, MXene has received increasing attention and favor from the photocatalysis community due to its regular planar structure, outstanding metal conductivity, surface adjustable chemical properties, abundant derivatives, and excellent optical and thermal properties. There is no doubt that the introduction of MXene has endowed the photocatalytic system with extraordinary performance and has made an important impact in the field of advanced catalysis and chemical technology. Herein, on the one hand, we summarize the synthetic route of MXenes and MXene-derived 0D quantum dots (MQDs), and propose the corresponding improved synthetic strategies for the defects of MXenes obtained by the current synthetic methods. On the other hand, recent progress in MXene-based photocatalysts has been reviewed to provide a comprehensive dissection of their designs and applications. It is highly anticipated that these will present researchers with a one-stop point for the state-of-the-art development of MXene-based photocatalysts. Finally, the future opportunities and challenges of MXenes in the flourishing field of photocatalysis are also discussed.