Curvularia trifolii is an important pathogenic fungus that causes leaf spot disease in strawberry and other crops. Increased resistance in pathogenic fungi against chemical fungicides necessitates the search for biological alternatives to control plant fungal diseases. The present study aimed to perform transcriptome and metabolome analysis of C. trifolii fungi. We evaluated the potential of an alkaloid, namely alpha (α)-solanine, to inhibit the growth of Curvularia under in vitro conditions. Furthermore, transcriptomic and metabolomic analysis of treated C. trifolii was performed to identify the differential genes and metabolites. Results revealed that treatment with α-solanine resulted in the poor growth and development of fungal spores. The transcriptome analysis revealed that 1413 genes were differentially expressed (DEGs), among which 340 unigenes were up-regulated, 100 unigenes were down-regulated, and the rest were unaffected in treated samples. Gene ontology analysis revealed that the majority of the genes were related to oxidative stress in the fungus. Additionally, using ultra-high performance liquid chromatography-tandem mass spectrometry, we identified 455 metabolites, among which the majority of metabolites were related to lipid biosynthesis. The high number of genes related to lipid biosynthesis and reactive oxygen species revealed that α-solanine causes oxidative stress in Curvularia, leading to growth inhibition, and can be potentially used as an alternative to chemical fungicides.

Cadmium (Cd) is a highly toxic pollutant and a nonessential element for plant growth. Here, we investigated the levels of malondialdehyde (MDA), H₂O₂, sugars, and the activity and gene expression of antioxidant enzymes and sugar metabolism-related enzymes in the mycelia of Pleurotus eryngii grown in the presence of 0, 0.5, 1, 1.5, 2.0, and 4.0 mg·L⁻¹ Cd. Raising Cd concentration resulted in increases, followed by decreases in the levels of malondialdehyde (MDA) and H₂O₂ in the mycelia. The maximum concentrations of MDA and H₂O₂ reached 318.61 and 7411.40 μmol·L⁻¹, respectively, at a Cd concentration of 1 mg·L⁻¹_. Antioxidative enzymes (superoxide dismutase (SOD), catalase, glutathione peroxidase (GPX), and ascorbate peroxidase (APX)) activities peaked at 1 mg·L⁻¹ Cd. Furthermore, Pleurotus eryngii produced trehalose, glucose, fructose, and maltose in the fermentation broth in response to Cd stress. The levels of trehalose, arabinose, and fructose in the fermentation broth decreased continuously. The levels of glucose increased continuously, whereas those of maltose first increased and then decreased. Gene expression level of chitin synthase, glucose-1-phosphate uridyl transferase peaked significantly at 2 mg·L⁻¹ of Cd, while that of trehalase 2 is 0.5 mg·L⁻¹, and those for fructose-diphosphate aldolase, glyceraldehyde-3-phosphate dehydrogenase, reached the maximum at 4 mg·L⁻¹.

Pleurotus citrinopileatus Singer (PCS) has attracted increasing attention as a raw material for medicine and food. Its quality is greatly affected by the accumulation of metabolites, which varies with the applied drying methods. In this study, we utilize an approach based on ultra-high-performance liquid chromatography/Q Exactive mass spectrometry (UHPLC-QE-MS) to reveal the metabolic profiles of PCS from three different drying methods (natural air-drying, NAD; hot-air-drying, HAD; vacuum freeze-drying, VFD). The results showed that lipids, amino acids and their derivatives were all important secondary metabolites produced during NAD, HAD and VFD treatments, with the key differential metabolites of PCS during drying including fifteen lipids and seven amino acids. Meanwhile, VFD was the best way for long-term preservation of dried PCS. Hot-drying methods, especially HAD, can improve the medicinal component of PCS. Furthermore, KEGG enrichment analysis highlighted 16 pathways and indicated that amino acid metabolism might be the key metabolite pathway for the PCS drying process. Our study elucidates the relationship between drying methods and metabolites or metabolic pathways of PCS to determine the mechanisms affecting the quality of PCS, and finally provides reference values for further development and application in functional food and medications.

To reduce the environmental impact of plastic packaging in the edible fungi supply chain, this study developed an edible natural chitosan composite film loaded with chlorogenic acid–chitosan oligosaccharide nanoparticles (CGA/COS NPs). The effects of CGA/COS NPs as additives on the structure and overall performances of chitosan-based films were systematically studied, and the application effect of nanoparticles/chitosan (NPs/CS) composite films in the preservation of Pleurotus geesteranus was explored. The results showed that the NPs had good compatibility with the film matrix, filled the voids of the chitosan matrix, enhanced the comprehensive performance of the film, and significantly improved the antioxidant activity of the film (DPPH free radical scavenging activity increased from 16.95% to 76.47%). Among all the films, the 5%NPs/CS composite film performed the best, not only having stronger barrier properties against moisture, oxygen, and ultraviolet rays, but also having the best thermal stability and mechanical properties, which can effectively extend the shelf life of Pleurotus geesteranus. This study developed a high-performance edible composite film, which provides a new path of great value for solving the preservation problem of perishable agricultural products such as Pleurotus geesteranus and promoting the innovative development of the green food packaging industry.