Leguminous plants significantly increase soil nitrogen cycling across global climates and ecosystem types.

Leguminous plants are an important component of terrestrial ecosystems and significantly increase soil nitrogen (N) cycling and availability, which affects productivity in most ecosystems. Clarifying whether the effects of legumes on N cycling vary with contrasting ecosystem types and climatic regions is crucial for understanding and predicting ecosystem processes, but these effects are currently unknown. By conducting a global meta-analysis, we revealed that legumes increased the soil net N mineralization rate (Rmin ) by 67%, which was greater than the recently reported increase associated with N deposition (25%). This effect was similar for tropical (53%) and temperate regions (81%) but was significantly greater in grasslands (151%) and forests (74%) than in croplands (-3%) and was greater in in situ incubation (101%) or short-term experiments (112%) than in laboratory incubation (55%) or long-term experiments (37%). Legumes significantly influenced the dependence of Rmin on N fertilization and experimental factors. The Rmin was significantly increased by N fertilization in the nonlegume soils, but not in the legume soils. In addition, the effects of mean annual temperature, soil nutrients and experimental duration on Rmin were smaller in the legume soils than in the nonlegume soils. Collectively, our results highlighted the significant positive effects of legumes on soil N cycling, and indicated that the effects of legumes should be elucidated when addressing the response of soils to plants.

Propyl acetate protects intestinal barrier during parenteral nutrition in mice and Caco-2 cells.

BACKGROUND: Gut microbiota dysbiosis induces intestinal barrier damage during parenteral nutrition (PN). However, the underlying mechanisms remain unclear. This study aimed to investigate gut microbiota dysbiosis, luminal short-chain fatty acids, and autophagy in a mouse model and how these short-chain fatty acids regulate autophagy. METHODS: Eight-week-old male specific-pathogen-free mice were randomly divided into a Chow group (standard diet and intravenous normal saline infusion) and a PN group (continuous infusion of PN nutrient solution) for 7 days. Caco-2 cells were also treated with intestinal rinse solutions from Chow and PN mouse models. RESULTS: Compared with the Chow group, the PN group exhibited increased Proteobacteria and decreased Firmicutes, correlating with decreased propyl acetate. In the PN group, intestinal tissue exhibited elevated adenosine monophosphate-activated protein kinase (AMPK) phosphorylation, LC3II protein levels, and Atg3 and Atg7 messenger RNA levels. P62 protein levels were decreased, indicating an increase of autophagy flux in the PN group. In the Caco-2 cell model, cells treated with PN solution plus propyl acetate exhibited increased Claudin-1 and occluding along with decreased interleukin-6 and tumor necrosis factor α compared with those treated with PN solution alone. Propyl acetate addition inhibited the AMPK-mammalian target of rapamycin (mTOR) pathway, mitigating the excessive autophagy induced by the PN intestinal rinse solution in Caco-2 cells. CONCLUSION: PN led to a significant reduction in propyl acetate levels in the intestine, excessive activation of autophagy, and barrier dysfunction. Propyl acetate inhibited excessive autophagy via the AMPK/mTOR signaling pathway and protected the intestinal barrier during PN.

Advances in the role of long non­coding RNAs and RNA­binding proteins in regulating DNA damage repair in cancer cells.

DNA damage and repair play a crucial role in the development, progression and treatment of cancer. In response to various types of DNA damage, the organism initiates a series of DNA damage responses that trigger post­DNA damage repair processes. Among the most severe forms of DNA damage are DNA double­strand breaks (DSBs), which can be repaired by the body through two pathways: Homologous recombination and non­homologous end joining. The repair of DNA damage, particularly DNA DSBs, significantly influences the sensitivity and resistance of cancer cells to chemotherapy and radiotherapy. Numerous studies have demonstrated that long non­coding RNAs (lncRNAs) can exert multiple regulatory effects on cancer cells by binding to RNA binding proteins (RBPs), thereby influencing DNA damage repair. Based on a comprehensive literature search, the existing research on the regulation of DNA damage repair by lncRNAs interacting with RBPs has primarily focused on the repair of DNA DSBs. Therefore, the present review discusses the regulatory effects of the interaction between lncRNAs and RBPs on DNA damage repair in cancer cells, with a specific focus on the repair of DNA DSBs and its implications in cancer. It is hoped that comprehensive analysis may enhance the current understanding of the molecular mechanisms underlying DNA damage repair in cancer and may lead to the identification of novel diagnostic biomarkers and potential therapeutic targets.

[Effects of corn-based cropping systems on phosphorus fractions and availability in red soil]. / çŽ‰ç±³ç§æ¤åˆ¶åº¦å¯¹çº¢å£¤ç£·ç´ å½¢æ€åŠå ¶æœ‰æ•ˆæ€§çš„å½±å“.

To clarify the effects of corn-based cropping systems on phosphorus (P) fractions and availability in red soil, we measured P fractions and availability of topsoil (0-20 cm) and subsoil (20-40 cm) in abandoned farmland (control) and three corn-based cropping systems (corn continuous cropping, zucchini-corn rotation and pea-corn rotation), respectively. The results showed that total P, available P contents and P activation coefficient in topsoil were higher than those in subsoil. The value of relative P parameters in topsoil of pea-corn rotation was the highest among all cropping systems. Organic P was the main P fraction in red soil, accounting for 57.8%-81.1% (topsoil) and 74.3%-85.5% (subsoil) of total P. Except for pea-corn rotation soil, sodium hydroxide extractable P (NaOH-P) was the main P fraction in other cropping systems. The contents of water-soluble P (H2O-P) and sodium bicarbonate extractable P (NaHCO3-P) with high availability were lower than other P fractions, only accounting for 0.3%-2.1% (topsoil) and 1.7%-10.0% (subsoil) of total P. The pea-corn rotation soil had the highest hydrochloric acid extractable P (HCl-P) content in topsoil and subsoil, and significantly differed from other cropping systems. The contents of available P, sodium bicarbonate extractable organic P (NaHCO3-Po), sodium hydroxide extractable organic P (NaOH-Po) and hydrochloric acid extractable inorganic P (HCl-Pi) were significantly correlated with pH, cation exchange capacity, iron-aluminum oxides and soil texture. In conclusion, pea-corn rotation was the most suitable system to improve P availability of red soil in Panxi area.