Chunsheng Hou

Carotenoids contribute to photoprotection and abiotic stress adaptation in plants, and lycopene cyclases (LCYs) occupy a key branch point in carotenoid biosynthesis. However, the composition and stress-responsive divergence of LCY genes in pepper remain insufficiently characterized. In this study, we identified six CaLCY genes in Capsicum annuum and analyzed their structural features and expression patterns under drought and salt stress. CaLCYB1 showed the strongest and most consistent induction under both drought and salt stresses and was positively correlated with carotenoid accumulation, whereas the other CaLCY members exhibited distinct or negligible expression patterns. Transient overexpression of CaLCYB1 significantly increased β-carotene and total carotenoid contents by 117.6% and 45.1%, respectively, relative to the empty-vector control, and also augmented ABTS^•+ radical scavenging activity as well as ascorbate peroxidase (APX) activity. Conversely, virus-induced gene silencing (VIGS) of CaLCYB1 led to marked reductions in all of these parameters. Correlation analysis, together with gain- and loss-of-function assays, supports an important role of CaLCYB1 in carotenoid accumulation and β,β-branch-related antioxidant responses under stress. Yeast two-hybrid screening identified three potential interactors of CaLCYB1, namely CaUBQ, CaLHP1, and CaLARP6B. This study provides a family-level characterization of LCY genes in pepper and identifies CaLCYB1 as a major stress-responsive member that directs carotenoid flux and enhances antioxidant capacity under abiotic stress.

Chinese sacbrood virus (CSBV) is highly lethal to Asian honey bee (Apis cerana) larvae. While gut symbionts are known to regulate viral infection, their role in CSBV pathogenesis remains poorly understood. Through 16S rRNA gene sequence analysis of the field-collected honey bees, we found that the larvae had a substantially higher relative abundance of Enterococcus than pupae or adults. Metagenome sequencing analysis of field-collected larvae demonstrated that CSBV infection significantly induced more than 45-fold enhancement in the abundance of Enterococcus faecalis, an opportunistic pathogen implicated in the development of purulent cystic lesions. In microbiota-free (MF) bees, colonization with E. faecalis markedly suppressed phospholipid metabolism and elevated levels of 4-guanidinobutyric acid and fructose-1,6-bisphosphate (FBP). These metabolic changes were associated with cytotoxicity and apoptosis, which worsened goblet cell damage and thereby facilitated CSBV infection, as indicated by metabolomics and pathological section analysis. Crucially, exogenous FBP administration directly enhanced cytotoxicity and apoptosis of gut in CSBV-infected MF bees, mirroring the CSBV susceptibility was mediated by E. faecalis. Our study unveiled a symbiotic bacteria's involvement in promoting RNA virus infection through metabolic reprogramming and epithelial barrier dysfunction, providing new insights into host-microbe-virus interactions in pollinators.

Bast fibrous plants are recognized as potential sources of pectin, yet the structural characteristics and functional properties of pectic polysaccharides derived from these plants remain insufficiently investigated. In this study, three pectic polysaccharides (HP, KP, and RP) were isolated from the bast fibers of Cannabis sativa L. (hemp), Hibiscus cannabinus L. (kenaf), and Boehmeria nivea L. (ramie) using an ammonium oxalate solution. Their chemical composition, monosaccharide profile, molecular weight, microstructure, and functional groups were analyzed by spectroscopic and chromatographic techniques. These polysaccharides exhibited remarkable uronic acid content (50.49–61.14%), a relatively low degree of esterification (19.51–34.26%), and high molecular weights ranging from 147.10 to 242.16 kDa. The predominant neutral sugars identified were rhamnose, arabinose, and galactose. Furthermore, HP, KP, and RP demonstrated superior thermal stability, emulsifying properties, water/oil holding capacity, and cholesterol binding ability compared with commercial citrus pectin (CP). They also exhibited stronger radical scavenging activity, with KP showing particularly notable antioxidant performance (IC₅₀ = 1856 and 1485 μg/mL for the DPPH and ABTS assays, respectively). Overall, these findings indicate that bast fibrous plants are promising alternative sources of pectic polysaccharides with favorable antioxidant properties, supporting their potential application as food additives or functional ingredients.

Lower respiratory infections predominantly affect children under five and the elderly, with influenza viruses and respiratory syncytial viruses (including SARS-CoV-2) being the most common pathogens. The COVID-19 pandemic has posed significant global public health challenges. While vaccination remains crucial, its efficacy is limited, highlighting the need for complementary approaches to mitigate immune hyperactivation in severe COVID-19 cases. Medicinal plants like Cannabis sativa show therapeutic potential, with over 85% of SARS-CoV-2-infected patients in China receiving traditional herbal treatments. This review explores the antiviral applications of cannabis and its bioactive compounds, particularly against SARS-CoV-2, while evaluating their pharmacological and food industry potential. Cannabis contains over 100 cannabinoids, terpenes, flavonoids, and fatty acids. Cannabinoids may block viral entry, modulate immune responses (e.g., suppressing pro-inflammatory cytokines via CB2/PPARγ activation), and alleviate COVID-19-related psychological stress. There are several challenges with pharmacological and food applications of cannabinoids, including clinical validation of cannabinoids for COVID-19 treatment and optimizing cannabinoid solubility/bioavailability for functional foods. However, rising demand for health-focused products presents market opportunities. Genetic engineering to enhance cannabinoid yields and integrated pharmacological studies are needed to unlock cannabis’s full potential in drug discovery and nutraceuticals. Cannabis-derived compounds hold promise for antiviral therapies and functional ingredients, though further research is essential to ensure safety and efficacy.

Precise identification of tumors is crucial for early diagnosis and treatment of cancer. However, spatially specific and sensitive molecular imaging of tumors remains a challenge due to issues such as low biomarker content and extra-tumor signal leakage. Endogenous purine/pyrimidine endonuclease 1 (APE1) is a marker for tumor diagnosis by detecting activity change and translocation from the nucleus into the cytoplasm. In this work, we developed a biosensor (named DNA/ZIF-8@Protein NPs) based on biomineralized metal-organic framework nanoparticles (MOF NPs) for sensitive detection and imaging of APE1 with the assistance of the rolling circle amplification reaction (RCA). In vitro experiments showed that based on the sensitivity of APE1 imaging, this biosensor can detect APE1 in the range of 0.005 to 2 U/mL with a detection limit of 0.0005 U/mL under optimal conditions. Functional probes and phi29 were loaded with ZIF-8, ensuring their simultaneous delivery to living cells. The results of in vivo experiments show that these DNA/ZIF-8@Protein NPs enable precise tumor cell identification and ultrasensitive molecular in situ tumor imaging by monitoring intracellular APE1. In summary, this method based on enzyme-activated RCA reaction provides new opportunities for ultrasensitive tumor in situ molecular imaging of tumor markers.

Natural plant nanocrystalline cellulose (NCC), a nanoscale biomaterial with exceptional physicochemical properties, has been extensively utilized in drug delivery systems. Nevertheless, its potential in mitigating nanoplastic toxicity remains largely unexplored. Here, we demonstrated that jute-derived NCC (JNCC) effectively alleviated polystyrene nanoplastic (nano-PS)-induced toxicity in honey bees by modulating gut microbiota. Comprehensive analyses, including survival assays, histopathological examination, transmission electron microscopy observation, and apoptosis detection, revealed that nano-PS exposure induced size-dependent cytotoxicity and severe autophagy-apoptosis activation in honey bees. Interestingly, JNCC treatment specifically enriched the core gut microbiota Gilliamella apicola and restored lipid metabolism pathways to attenuate these acute injuries in both the gut and trachea of nano-PS-treated honey bees. Metabolomic analysis further confirmed JNCC-mediated upregulation of glycerophospholipid metabolism, with a marked increase in associated metabolites, including hexadecanamide and glycerophospho-N-palmitoyl ethanolamine (GP-NPEA), which is a regulator of the apoptosis pathway. Colonization with G. apicola significantly inhibited cytotoxicity and apoptosis induced by PS nanoplastic treatment in JNCC-treated honey bees, but this obviously restored lipid metabolism to relieve PS nanoplastic-induced acute injuries in the gut. Our findings highlighted the ability of JNCC to mitigate nanoplastic toxicity by regulating microbiota-metabolite networks, suggesting its potential as a therapeutic option for environmental pollutant exposure in animals.