The senescence of fruit is a complex physiological process, with various cell types within the pericarp, making it highly challenging to elucidate their individual roles in fruit senescence. In this study, a single-cell expression atlas of the pericarp of pitaya (Hylocereus undatus) is constructed, revealing exocarp and mesocarp cells undergoing the most significant changes during the fruit senescence process. Pseudotime analysis establishes cellular differentiation and gene expression trajectories during senescence. Early-stage oxidative stress imbalance is followed by the activation of resistance in exocarp cells, subsequently senescence-associated proteins accumulate in the mesocarp cells at late-stage senescence. The central role of the early response factor HuCMB1 is unveiled in the senescence regulatory network. This study provides a spatiotemporal perspective for a deeper understanding of the dynamic senescence process in plants.

It has been revealed in our previous studies that trypsin scavenges superoxide anions. In the current study, the mechanisms of storage quality improvement by trypsin were evaluated in H. undatus. Strikingly, the improvement is due not to its antibacterial or antifungal activity but to its superoxide scavenging activity. Moreover, trypsin significantly decreased the levels of ROS, cell permeability and membrane lipid peroxidation. The activities of major antioxidant enzymes were significantly improved by trypsin treatment. Transcriptome profiles of H. undatus treated with trypsin revealed the pathways and regulatory mechanisms of antioxidant genes up or down-regulated following trypsin treatment by Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes pathway (KEGG) enrichment analyses. The results of protein–protein interaction networks indicated that CAT is the key among the enzymes of the complicated antioxidant system. In addition, the current results showed that the synergistic effect of trypsin with antioxidant enzymes can regulate the levels of endogenous active oxygen species, reduce malondialdehyde content, improve cell membrane integrity, alleviate cell damage and delay fruit ageing.

The purpose of this study was to evaluate the effects of astragalin on the central nervous system. Astragalin is a monomeric compound found in the leaves of Eucommia ulmoides using a system solvent method. In the experiments, astragalin showed significant effects on mice, including reduced spontaneous activity, increased sleep ratio, shortened sleep latency and lengthened sleep time with a subthreshold or superthreshold dose of pentobarbital sodium. In addition, astragalin effectively reduced the convulsion rate and prolonged convulsion latency. These findings confirmed that astragalin had excellent sedative and hypnotic effects and has potential to be commercialised as a novel nutraceutical agent to promote calming and improve central nervous system-associated pathologies.