Haikou Experimental Station

Fusarium wilt of banana, caused by Fusarium oxysporum f. sp. cubense (Foc), is a destructive vascular disease that seriously threatens global banana production. To investigate the contribution of histidine metabolism to Foc growth and pathogenicity, we functionally characterized FoHis2, a putative histidinol-phosphate phosphatase in Foc race 4 (Foc4). Targeted deletion of FoHis2 severely compromised histidine prototrophy, with the ΔFoHis2 mutant growing slowly on potato dextrose agar and even more slowly on minimal medium (MM, no histidine added). Exogenous histidine fully restored the mutant growth to wild-type (WT) levels, whereas histidinol supplementation rescued the colony size but not the reduced aerial mycelium formation. The ΔFoHis2 mutant exhibited markedly reduced vegetative growth and hyphal branching, and increased sensitivity to elevated H2O2 concentrations, compared with the WT strain. Consistent with the oxidative stress phenotype, peroxisome-associated genes were down-regulated in the ΔFoHis2 mutant. FoHis2 was dispensable for conidiation, cell wall integrity, and fusaric acid and beauvericin biosynthesis. Pathogenicity assays showed that the deletion of FoHis2 severely compromised cellophane penetration and greatly reduced disease incidence and severity on Cavendish banana plantlets, whereas genetic complementation restored the WT phenotypes. These results indicate that FoHis2-mediated histidine biosynthesis is essential for metabolic homeostasis, stress adaptation, and full virulence in Foc4, and highlight histidine metabolism as a potential target for controlling Fusarium wilt in banana.

BackgroundGraduate students face considerable health risks due to sedentary behavior and academic stress, often demonstrating a marked intention–behavior gap in physical activity (PA). This study developed a two-dimensional 9-box grid model based on total exercise volume (TEV) and aerobic capacity (AC) to compare the efficacy of weekly versus monthly feedback in improving AC and PA participation among graduate students.MethodsA quasi-experimental trial was conducted over eight weeks. Thirty-two graduate students, stratified by baseline AC evaluated in a 12-minute run test, were randomized into two arms, weekly feedback (n = 16) and monthly feedback (n = 16). Feedback was delivered through a dynamic 9-box grid that integrated weekly TEV on the x-axis and periodic AC on the y-axis. The primary outcomes were changes in the 12-minute run performance and TEV. Secondary outcomes included scores from the Exercise Identity Scale (EIS) and the Self-Efficacy for Exercise Scale (SEE-C). Thirty graduate students (n = 15 per group) completed the trial and were included in the final analysis.ResultsSignificant group × time interactions were observed for 12-min run distance (F = 4.29, p = 0.024, η2 = 0.241) and score (F = 6.49, p = 0.005, η2 = 0.325). The weekly feedback group demonstrated sustained improvements across all intervals (p < 0.001, Hedges’ g = 1.16–1.78), while the monthly group improved only post-intervention. Weekly feedback also resulted in significantly greater gains in self-efficacy (p = 0.044, g = 0.77) and higher TEV scores at multiple timepoints (p < 0.05). Both groups showed improved exercise identity (p < 0.001), with no between-group difference. Center of gravity analysis indicated greater migration toward healthier grid zones in the weekly group (ΔG = −1.93 vs. −1.47).ConclusionThe dynamic 9-box grid model effectively enhances aerobic capacity, promotes physical activity, and strengthens psychological outcomes through dual-axis evaluation and closed-loop feedback. Weekly feedback demonstrates superior efficacy in sustaining behavior modification and facilitating tier progression. This model provides a replicable, theory-informed strategy for health behavior management in graduate student populations.

Propagation of rubber tree (Hevea brasiliensis) via secondary somatic embryogenesis (SSEis) is a reliable method. However, its efficiency is relatively low. The aim of this study was to understand more about the factors related to SSEis in rubber trees, trying to improve the efficiency of somatic embryo (SE) yield. Our study showed that the orientations of explants, i.e., the fragments of primary SE (PSE), on the medium affected secondary SE (SSE) yield significantly. Among five experimental tests, the highest yield was 2.6 ± 0.9 secondary somatic embryos (SSEs) per explant, which was achieved by orienting the abaxial side of the explant in contact with the medium and then the adaxial side after a period of culture time. Based on histological evidence, SSEis was induced from the epidermal cells and adjacent cells on the adaxial side of the explants. A remarkable difference in embryogenic capacity difference existed among individual PSE. The concentrations of soluble proteins, starch, soluble sugars, and the superoxide dismutase activity (SOD) levels in the explants were measured during a 25-day long SSEis induction treatment and compared between explants of high and low embryogenic capacity. This study proves that the explant orientation toward the culture medium plays a crucial role in SSEis, while the concentration changes of these biochemical compounds correlate to morphological changes in the explants during induction, as do the changes in SOD activity. Furthermore, the trend of the dynamic changes in the explants reflected a process of de-differentiation and re-differentiation, which started from mature SE tissues during SSE induction.

The embryonic development of the biliary system is orchestrated by complex signaling pathways, including Notch, TGF-β, Wnt, and GFs, which regulate biliary stem/progenitor cell fate, polarity, and ductal morphogenesis. These pathways not only govern physiological development but are also deeply implicated in pathological processes such as inflammation, fibrosis, and carcinogenesis. However, conventional two-dimensional culture systems and animal models fall short in replicating the spatial structure, developmental dynamics, and human-specific molecular context of the biliary tract. As a result, bile duct organoids derived from various cellular sources have emerged as powerful in vitro platforms, capable of reconstructing key features of biliary architecture and function. Organoids not only respond to, but also enable the controlled manipulation of, developmental signaling pathways. These systems have revealed the dual roles of Wnt, Notch, TGF-β, and GFs in both tissue homeostasis and disease progression. Recent studies have successfully applied biliary organoid models to explore the mechanisms underlying primary sclerosing cholangitis, biliary atresia, cholangiocarcinoma, and gallbladder cancer, identifying critical signaling axes and regulatory networks. This review systematically reviews the roles of key signaling pathways in bile duct development and their regulatory mechanisms in organoid construction, with a particular focus on the applications of organoid models in elucidating signaling pathway abnormalities, uncovering disease mechanisms, and identifying potential therapeutic targets. It further provides a perspective on their prospects and challenges in the development of precision therapeutic strategies and clinical translation.

ABSTRACT There is no vaccine for severe malaria. STEVOR antigens on the surface of Plasmodium falciparum-infected red blood cells are implicated in severe malaria and are targeted by neutralizing antibodies, but their epitopes remain unknown. Using computational immunology, we identified highly immunogenic overlapping B- and T-cell epitopes (referred to as multiepitopes, 7–27 amino acids) in the semiconserved domain of four STEVORs linked with severe malaria and clinical immunity. Structural analyses confirmed the conservation in homologous sequences across 138 clinical isolates (Togo and Brazil) and 342 global strains. Designed fused multiepitopes showed high IgG antibody reactivity in the sera of P. falciparum-infected individuals. The fused multiepitopes had no allergenicity/toxicity, and phenotyping via flow cytometry and immunological assays revealed the induction of CD4+ and CD8+ T-cell proliferation and IgG antibodies in BALB/c mice, respectively. On this basis, structure-guided design of a multiepitope fusion antigen (MEFA) vaccine construct achieved 97.15% global combined HLA coverage and elicited both cellular and humoral immunity in silico. Recombinant MEFA was stably expressed in Escherichia coli and recognized significantly more anti-STEVOR IgG antibodies in the sera of nonsevere malaria cases than in those of severe cases, underscoring its potential immunogenicity and association with milder disease. The STEVOR MEFA construct emerges as a promising severe malaria vaccine candidate, combining global HLA coverage, safety, and broad immunogenicity linked to milder clinical outcomes.

Phytophthora capsici, a highly destructive pathogen affecting solanaceous and cucurbitaceous crops globally, poses a significant threat to agricultural production and food security. Neoechinulin A (NEA), an isoprenyl indole alkaloid, was previously known for its anti-inflammatory properties, but had not been reported for its antioomycete effects. NEA demonstrated potent antioomycete activity against P. capsici, with an EC50 value of 21.95 μg/mL. In vitro and in vivo assays demonstrated that NEA effectively inhibited mycelial growth, sporangium formation, and zoospore motility of P. capsici mycelium, while also enhancing the protective capacity of pepper plants. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) revealed that NEA caused significant morphological alterations in P. capsici filaments, leading to the disruption of cell membrane integrity, vacuole swelling and rupture of the vacuolar membrane, severe plasmolysis, along with the disappearance of most organelles. Moreover, NEA induced an increase of malondialdehyde (MDA) content in P. capsici mycelium, accompanied by a reduction in the activities of antioxidant enzymes and a decrease in soluble protein levels. Transcriptome data analysis revealed that NEA affected the expression of genes involved in glycolysis/gluconeogenesis, pyruvate metabolism, and glutathione metabolism, which resulted in a reduction of pyruvate, ATP, and glutathione (GSH) levels, thereby disrupting energy metabolism and causing cellular dysfunction in P. capsici. These findings indicated that NEA could effectively control diseases caused by P. capsici and showed promise as a potential novel fungicide for managing Phytophthora blight. © 2025 Society of Chemical Industry.