Fusarium solani is one of the primary pathogens causing root rot of wolfberry. The aims of this study were to investigate the inhibitory effect of potato glycoside alkaloids (PGA) on F. solani and its energy metabolism. In this study, the effects of PGA treatment on the growth and development of F. solani were investigated and the changes in the glycolytic pathway (EMP), ATPase activity, mitochondrial complex activity, mitochondrial structure, and energy charge level were analyzed to elucidate the possible antifungal mechanism of PGA on F. solani. The results showed that PGA treatment inhibited the colony growth, biomass, and spore germination of F. solani. PGA treatment reduced the glucose content and Hexokinase (HK) activity of F. solani, but increased the activity of Fructose-6-Phosphate Kinase (PFK) and Pyruvate Kinase (PK) and promoted the accumulation of pyruvic acid. In addition, PGA treatment inhibited the activities of H⁺-ATPase, Ca²⁺-ATPase, and mitochondrial complex IV, increased the mitochondrial inner membrane Ca²⁺ content and mitochondrial membrane permeability transition pore, and decreased the contents of ATP, ADP, and AMP as well as the energy charge. These results indicate that PGA treatment inhibits the growth and development of F. solani, activates the glycolysis pathway, inhibits ATPase activity and mitochondrial complex activity, and destroys the structure and function of mitochondrial membrane, resulting in a lower energy charge level.

Wolfberry (Lycium barbarum) is a vital economic tree species in northwest China, but root rot caused by Fusarium solani occurs frequently, which seriously endangers the quality and yield of wolfberry. In this study, potato glycoside alkaloids (PGAs), a plant-derived active substance, were used as materials to explore its inhibitory effect on F. solani. By analyzing the changes of reactive oxygen species (ROS) level, antioxidant capacity, and apoptosis, the role of PGAs-mediated oxidative stress in inducing apoptosis of F. solani was revealed. The findings suggest that PGAs treatment inhibited mycelium growth, reduced biomass and sporulation, and delayed spore germination in F. solani. The concentration for 50% of maximal effect (EC₅₀) was 1.85 mg/mL. PGAs treatment induced an increase in caspase-3 activity, disrupting the cell membrane of fungi. In addition, PGAs treatment activated NADH oxidase (NOX) and superoxide dismutase (SOD), promoted hydrogen peroxide (H₂O₂) and superoxide anion (O₂⁻) accumulation, and decreased ascorbate peroxidase (APX), glutathione reductase (GR), and dehydroascorbate reductase (DHAR) activities as well as oxidized glutathione (GSSG), reduced glutathione (GSH), and electron donor NADPH content. In summary, PGAs has a strong inhibitory effect on F. solani, and its inhibitory effect may be related to the promotion of ROS accumulation by PGAs, causing the disorder of intracellular redox balance of fungi, the decrease of total antioxidant capacity, and finally the induction of apoptosis. This study provides a new insight into the antifungal mechanism of PGAs against F. solani.

Wolfberry (Lycium barbarum) is an important economic crop with extremely high medicinal value; however, root rot disease leads to a serious decline in the yield and quality of wolfberry. In this study, we used one-year-old wolfberry seedlings as test material to explore the control effect of single or combined inoculation with arbuscular mycorrhizal (AM) fungus Rhizophagus intraradices and endophytic fungus Metarhizium robertsii on wolfberry root rot and preliminarily probed the related disease resistance mechanisms. The results showed that both R. intraradices and M. robertsii could successfully colonize the roots of wolfberry, and the combined inoculation significantly increased the colonization rate of R. intraradices and reduced the incidence of wolfberry root rot, with a control effect of 68%. Combined inoculation enables plants to absorb nitrogen and phosphorus more effectively by increasing the nutrient uptake area and activity of wolfberry roots, which helps to increase chlorophyll content and promote plant growth. It also improved the resistance of wolfberry to root pathogens by regulating endogenous hormones (significantly increasing the contents of salicylic acid, indole-3-acetic acid, gibberellin A3, and decreasing the content of abscisic acid) and enhancing defensive enzyme activities (superoxide dismutase, peroxidase, and ascorbate peroxidase). In terms of soil, the combined inoculation significantly increased the nitrogen content and enzyme activities (sucrase, urease, and catalase), creating a more favorable growth environment for wolfberry. In conclusion, AM fungus R. intraradices combined with endophytic fungus M. robertsii can effectively enhance the disease resistance of wolfberry to root rot and has certain biocontrol application potential (Graphical abstract).

Background: Gumming disease caused by Fusarium tricinctum severely threatens Zanthoxylum bungeanum production. This study investigated the antifungal potential of volatile organic compounds (VOCs) produced by an endophytic fungus, Schizophyllum commune, isolated from Z. bungeanum. Methods: A dual-culture assay evaluated VOCs inhibition against F. tricinctum. Compounds were identified using headspace solid-phase microextraction gas chromatography-mass spectrometry, and the antifungal mechanism of this component was explored. Results: VOCs from S. commune significantly inhibited mycelial growth and sporulation of the pathogen. Among 53 identified compounds, 1-octen-3-ol (mushroom alcohol) was the most abundant (35.98% relative content) and exhibited strong antifungal activity with an EC₅₀ of 0.15 µL/mL against F. tricinctum. Mechanistically, 1-octen-3-ol disrupted cell membrane integrity by increasing alkaline phosphatase and β-1,3-glucanase activities, leading to enhanced permeability and content leakage. It also induced oxidative stress by promoting reactive oxygen species accumulation via elevated NADPH oxidase and superoxide dismutase activities, while suppressing antioxidant enzymes. Conclusions: 1-octen-3-ol inhibits F. tricinctum through membrane disruption and oxidative stress, offering a promising eco-friendly strategy for controlling gumming disease.