Fresh wolfberries are highly susceptible to postharvest fungal decay, resulting in severe economic losses. A strain isolated from naturally diseased wolfberries and identified as Alternaria alternata via multi-gene phylogenetic analysis was used as the test pathogen. The antifungal activity and mechanism of mushroom alcohol were investigated using a fumigation method. The half-maximal effective concentration (EC₅₀) was determined as 0.127 mL/L. At this concentration, effects on mycelial growth, spore germination, and penetration ability were evaluated. Scanning electron microscopy, transmission electron microscopy, and fluorescence staining were employed to observe morphological and cell wall alterations. Contents of major cell wall components, related enzyme activities, and transcriptomic profiles were analyzed. In vivo experiments were also conducted under natural disease and artificial inoculation conditions. Results showed that EC₅₀ treatment significantly inhibited mycelial growth, spore germination, and penetration, causing mycelial shrinkage, cell wall loosening and thickening, and uneven fluorescence distribution. Biochemical assays revealed a marked decrease in β-1,3-glucan content and significantly increased activities of chitinase, β-1,3-glucanase, and chitin synthase. Transcriptomic analysis confirmed the coordinated upregulation of genes involved in chitin and β-1,3-glucan metabolism, indicating aberrant cell wall remodeling. In vivo, mushroom alcohol fumigation reduced natural disease incidence by 75.5% and effectively delayed disease development while reducing lesion diameters under artificial inoculation. Collectively, mushroom alcohol exerts its antifungal activity by interfering with cell wall metabolism and disrupting structural integrity, indicating its potential as a natural preservative for postharvest wolfberry disease control.

Objective: Syringa leaf extract (SLE) is a promising green feed additive with antibacterial and anti-inflammatory activities, mainly attributed to its main bioactive component tyrosol. However, its large-scale application is limited by the lack of an optimized spray drying process that ensures both process efficiency and tyrosol stability. Methods: This study optimized the spray drying process of SLE with powder yield and moisture content as core indicators, using maltodextrin as a carrier material. Plackett-Burman (PB) design screened inlet air temperature, atomization frequency and feeding speed as key factors from six parameters. Box-Behnken design (BBD) combined with response surface methodology was then used for further optimization, and thermogravimetric analysis verified the thermal stability of tyrosol, the main bioactive component of SLE. The optimized process was validated by determining the angle of repose, solubility, dispersibility, and tyrosol content. Results: The optimal parameters were determined as inlet air temperature 163 degrees C, atomization frequency 349Hz and feeding speed 17 r & centerdot;min(-1), under which three verification batches yielded an average powder yield of 82.8% and moisture content of 2.19%, consistent with model predictions. Tyrosol was stable below 225.1 degrees C, matching the spray drying temperature range. Physical property tests confirmed excellent flowability, solubility and dispersibility of the optimized SLE powder, and tyrosol content determination in nine batches showed a coefficient of variation of 4.38%, indicating good process stability. Conclusion: The spray drying process optimized by the PB combined with Box-Behnken method is stable, feasible, and reproducible, which can provide a scientific reference for the large-scale preparation production of SLE.

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 1-year-old wolfberry seedlings as test material to explore the control effect of single or combined inoculation with the arbuscular mycorrhizal (AM) fungus Rhizophagus intraradices and the 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, and 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, the AM fungus R. intraradices combined with the endophytic fungus M. robertsii can effectively enhance the disease resistance of wolfberry to root rot and has certain biocontrol application potential.

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.

To evaluate the impact of different agronomic activities on soil physicochemical properties and Ncycling gene abundances in farmland soil near copper tailings area. The pot experiments were performed from September 11 to December 5 in 2023, soil physiochemical properties, abundance of nifH, AOA-amoA, AOBamoA, nirS, nirK and nosZ, and variation of N-cycling bacterial population were investigated. Results showed that combined application of Chinese milk vetch and N fertilizer significantly decreased soil pH while increasing the levels of total nitrogen, organic matter, available nitrogen, nitrate nitrogen, urease activity, alkaline proteinase activity, and abundances of nifH, AOA-amoA, andAOBamoA. Results of multiple regression analysis suggested that the abundance of nifH, AOA-amoA,AOBamoA, nirS and nosZ negatively correlated with pH (p < 0.05), and positively correlated with available N, nitrate nitrogen and alkaline proteinase activity (p < 0.01), and the abundance of nosZ correlated positively with available nitrogen and nitrate nitrogen. The main driving factors for N fixation, nitrification and denitrification, were Hyphomicrobium, Nitrospira and Nitrosospira, respectively. Combined agronomic practices had a better role in improving the cadmium-containing soil properties than the unitary Chinese milk vetch planting or N fertilizer alone. Therefore, pH, available nitrogen and nitrate nitrogen were crucial environmental factors for the abundances of nitrogen cycle genes.

Fusarium solani is a widely distributed pathogenic fungus that can cause soil borne diseases in various plants and is also one of the main pathogenic bacteria of Lycium barbarum root rot. This study employed tandem mass labeling (TMT) quantitative proteomics technology to investigate the antifungal mechanism of potato glycoside alkaloids (PGA) against Fusarium solani. We elucidated the antifungal mechanism of PGA from the perspective of mitochondrial proteome molecular biology. Furthermore, we identified and annotated the differentially expressed proteins (DEP) of F. solani under PGA stress. A total of 2,412 DEPs were identified, among which 1,083 were significantly up-regulated and 1,329 significantly down-regulated. Subsequent analysis focused on five DEPs related to energy metabolism for verification at both protein and gene levels. Gene Ontology (GO) function analysis revealed that the DEPs were primarily involved in the integral component of the membrane, intrinsic component of the membrane, pyridine-containing compound metabolic processes, carbon-oxygen lyase activity, and the endoplasmic reticulum, with a notable enrichment in membrane components. Furthermore, a total of 195 pathways were identified through KEGG analysis, with significant enrichment in critical pathways including pentose and glucuronate interconversions, propanoate metabolism, various types of N-glycan biosynthesis, the pentose phosphate pathway, and carbon fixation in photosynthetic organisms. The results from both parallel reaction monitoring (PRM) and real-time RT-qPCR were consistent with the overall trends observed in TMT proteomics, thereby confirming the validity of the TMT proteomics analysis. These findings indicate that PGA inhibits the growth of F. solani by impacting mitochondrial energy metabolism. This study reveals the antifungal mechanism of PGA from the perspective of energy metabolism, providing a theoretical basis for the development and application of PGA as a biopesticide.

Wolfberry (Lycium barbarum) is an important economic tree species in northwest China. The postharvest decay of fresh wolfberry fruit, caused by infection from Alternaria spp., has become increasingly serious. In this study, the inhibitory mechanism of mushroom alcohol treatment on Alternaria tenuissima was researched using the fumigation method. The results indicated that treatment with mushroom alcohol at a concentration of 0.188 mL/L (50% of maximal effect), effectively inhibited the growth of A. tenuissima mycelium, and reduced biomass and sporulation. Mushroom alcohol treatment increased the activity of superoxide dismutase in A. tenuissima, promoted the accumulation of superoxide anion and hydrogen peroxide in the early stages of culture, inhibited the activity of catalase and polyphenol oxidase, and disturbed the balance of antioxidant metabolism. Furthermore, mushroom alcohol treatment reduced the activity of dehydroascorbate reductase, monodehydroascorbate reductase, and glutathione peroxidase and decreased the amount of antioxidants, resulting in decreased pathogen resistance. The treatment also damaged the cell membrane structure of A. tenuissima, leading to increased relative conductivity, malondialdehyde accumulation, and extensive leakage of nucleic acids and proteins. After the wolfberry was inoculated with the pathogenic fungus, mushroom alcohol treatment significantly reduced wolfberry disease incidence and lesion area. This treatment delayed disease onset and reduced disease severity in harvested wolfberry, suggesting its potential for postharvest fruit preservation.

Wolfberry (Lycium barbarum), a member of the Solanaceae family, is recognized as a pioneering tree species for afforestation in saline-alkali soils and holds significant economic value as a forest species. Its fruit is abundant in bioactive compounds that contribute in both ecological health and human well-being. The WRKY gene family has been extensively studied across various species, with its members’ functions increasingly elucidated. However, limited research has focused on the role of the WRKY genes of L. barbarum, particularly in resistance to root rot. This study identified the bioinformatics of 104 WRKY genes in wolfberry, encompassing phylogenetics, conserved motifs, gene structures, synteny, and collinearity. Based on structural and phylogenetic, the 104 LbWRKYs are divided into three main groups, Group I, II and III, with 26, 62 and 15 members, respectively. Synteny analysis revealed high homology between LbWRKY and tomato SlWRKY, with a total of 117 pairs of homologous genes identified. Cis-acting elements analysis demonstrated that subgroup II LbWRKY genes contained a higher number of plant hormone-related regulatory elements. Furthermore, 28 LbWRKY genes were found to respond to the infection of Fusarium solani. Protein-protein interaction prediction and correlation analyses revealed that associations between LbWRKY genes and flavonoid and phenylpropanoid synthesis-related genes, and the results showed that LbWRKY8/100/63/84/102/42/45 was involved in the mechanism of root rot resistance. Expression analysis following Fusarium solani inoculation confirmed that these genes participate in root rot resistance in L. barbarum. This study provides valuable insights into the functional roles of LbWRKY genes, and establishing a foundation for future research on their involvement in secondary metabolite synthesis and their role in enhancing the disease resistance of L. barbarum.

In order to effectively alleviate the continuous cropping obstacles in Zanthoxylum bungeanum forests, different volume ratios of bio-organic fertilizer and microbial fertilizer were used as remediation agents to investigate their effects on phenolic acids in continuous cropping soil and physiological and biochemical characteristics of replanted Z. bungeanum seedlings. The results showed that the combined application of bio-organic fertilizer and microbial fertilizer significantly reduced the contents of gallic acid (GA) and caffeic acid (CA) in continuous cropping soil (p < 0.05) and the content of malondialdehyde (MDA) in Z. bungeanum leaves and increased the activity of catalase (CAT) in leaves (p < 0.05). Compared with the control group without fertilization (T0), the lowest MDA content, the highest superoxide dismutase (SOD), peroxidase (POD) and CAT activities, and the highest accumulation of soluble sugars (SSs) and soluble proteins (SPs) were observed under the T6 treatment (2:1 volume ratio of microbial fertilizer to bio-organic fertilizer). The comprehensive evaluation results of principal components showed that the T6 treatment had the highest comprehensive score. That is, the alleviation effect was most pronounced when the volume ratio of microbial fertilizer and bio-organic fertilizer was 2:1 in combination. This study confirms the potential of biofertilizer combined application technology for repairing continuous cropping obstacles and provides a scalable ecological fertilization scheme for the sustainable cultivation of Z. bungeanum.

Fresh-cut taro slices were treated with varying concentrations of glycolic acid (GA) solution (0.05, 0.1, 0.2, and 0.5 mg/L) prior to cold storage and 0.2 mg/L GA was used to further investigate GA effects on browning inhibition. After 12 d of cold storage, treatment with 0.2 g/L GA resulted in a 27.77 % or 51.91 % reduction in browning index, indicating GA treatment effectively reduced enzymatic browning in taro slices. Metabolomics profiling revealed that GA treatment decreased the abundance of 11 metabolites in lipid metabolism pathways. Transcriptome, weighted gene co-expression network analysis (WGCNA) and gene set enrichment analysis (GSEA) suggested a close correlation between lipid metabolism and GA-mitigated browning. In addition, GA application reduced both glycolate oxidase activity and H2O2 contents, while enhancing peroxidase activity and gene expression. The results suggest that GA application reduces sliced-taro browning by diminishing ROS level and mitigating membrane lipid metabolism.

Fusarium solani is a pathogenic fungus that causes significant harm, leading to crop yield reduction, fruit quality reduction, postharvest decay, and other diseases. This study used potato glycoside alkaloids (PGA) as inhibitors to investigate their effects on the mitochondrial structure and tricarboxylic acid (TCA) cycle pathway of F. solani. The results showed that PGA could inhibit the colony growth of F. solani (54.49%), resulting in the disappearance of the mitochondrial membrane and the loss of contents. PGA significantly decreased the activities of aconitase (ACO), isocitrate dehydrogenase (IDH), α-ketoglutarate dehydrogenase (α-KGDH), succinate dehydrogenase (SDH), fumarase (FH), malate dehydrogenase (MDH), succinyl-CoA synthetase (SCS), and increased the activity of citrate synthase (CS) in F. solani. After PGA treatment, the contents of acetyl coenzyme A (CoA), citric acid (CA), malic acid (L-MA), and α-ketoglutaric acid (α-KG) in F. solani were significantly decreased. The contents of isocitric acid (ICA), succinyl coenzyme A (S-CoA), succinic acid (SA), fumaric acid (FA), and oxaloacetic acid (OA) were significantly increased. Transcriptomic analysis showed that PGA could significantly affect the expression levels of 19 genes related to TCA cycle in F. solani. RT-qPCR results showed that the expression levels of ACO, IDH, α-KGDH, and MDH-related genes were significantly down-regulated, and the expression levels of SDH and FH-related genes were significantly up-regulated, which was consistent with the results of transcriptomics. In summary, PGA can achieve antifungal effects by reducing the tricarboxylic acid cycle’s flow and regulating key genes’ expression levels. This study reveals the antifungal mechanism of PGA from the perspective of TCA cycle, and provides a theoretical basis for the development and application of PGA as a biopesticide.

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.

Abstract To solve the issues of low survival rate and poor vigor of Zanthoxylum bungeanum seedlings caused by long-term continuous cropping, a study was conducted using bio-organic fertilizer and microbial bacterial fertilizer as repair agents. The aim was to investigate their effects on the physiological metabolism of Zanthoxylum bungeanum seedlings and soil phenolic acids, with a focus on understanding the growth-promoting mechanism of replanted Zanthoxylum bungeanum. The results revealed that fertilization significantly increased the activities of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), nitrate reductase (NR), as well as the levels of soluble sugar (SS) and soluble protein (SP) in Zanthoxylum bungeanum seedlings. Conversely, the content of malondialdehyde (MDA) and four soil phenolic acids (gallic acid (FA), ferulic acid (GA), caffeic acid (CA), and p-hydroxybenzoic acid (PHBA) were significantly reduced. The mixed application of microbial fertilizer and bio-organic fertilizer showed better growth-promoting effects compared to single application. Specifically, when the volume ratio of microbial fertilizer and bio-organic fertilizer was 2:1, the activity of defense enzymes was most significantly promoted. Under this treatment, the activities of SOD, CAT, POD, and NR in seedlings were 1.8, 3, 3.8, and 5.3 times higher than the control (no fertilization treatment), respectively. The levels of SS and SP were 2.4 and 2.5 times higher than the control, respectively. The MDA content was 27% of the control, and the total content of the four phenolic acids was 60% of the control. Principal component analysis results showed that the scores of fertilization treatments were higher than the control, with the order being T6 > T7 > T2 > T5 > T4 > T3 > T1 > T0. Therefore, the combined application of microbial fertilizer and bio-organic fertilizer effectively promotes the physiological metabolism of seedlings, reduces the content of soil phenolic acids, and has a positive effect on alleviating the obstacles to continuous cropping of Zanthoxylum bungeanum.

Trichothecium roseum is an important postharvest pathogenic fungus. Within its molecular framework, the epigenetic reader Snt2 emerges as a key player, capable of modulating fungal growth, development, autophagy, and pathogenicity. However, the role of TrSnt2 in regulating autophagy, reactive oxygen species (ROS) accumulation, ergosterol synthesis, and the pathogenicity of T. roseum remains unexplored. In this study, we showed that Trsnt2 deletion increased the acetylation level of H3 and simultaneously upregulated the expression of 15 autophagy genes (Atg1, 2, 5, 8-14, 16, 18, 20, 22, 24), thereby promoting autophagosome formation and mitophagy in T. roseum mycelia. Remarkably, Trsnt2 deletion exerted a dual effect on ROS dynamics: it downregulated the expression of ROS production-related genes (NoxA, NoxB, and SOD), while also dampening the expression of ROS scavenging-related genes (CAT, CTT1, POD, APX, GPX, and TrxB), ultimately resulting in decreased ROS accumulation in the mycelia. Furthermore, Trsnt2 deletion orchestrated a shift in the expression profile of genes associated with the late pathway of ergosterol synthesis (Erg2, Erg3, Erg5, and Erg6) in addition to the downregulation of Erg4. This cascade of events led to significant membrane damage and subsequent cell death. Furthermore, the effect of Trsnt2 deletion extended to the pathogenicity of T. roseum on muskmelon and tomato fruit, where a reduction in pathogenicity was observed. In conclusion, Trsnt2 emerges as a critical regulator in shaping T. roseum pathogenicity on fruit, orchestrating a complex interplay of cellular processes.

As an epigenetic reader, Snt2 is involved in the regulation of phenotype and pathogenicity of some filamentous fungi. However, whether Snt2 is involved in the regulation of phenotype and pathogenicity of Trichothecium roseum has not been reported. In this study, snt2-deleted strain of T. roseum and its complementation were constructed based on bioinformatics analysis to investigate the effects of Trsnt2 on the phenotype and pathogenicity of T. roseum. The results showed that the Snt2 protein in T. roseum has a high homology to that of Fusarium albosuccineum. The protein contains one BAH domain, two PHD domains, one SANT domain and one ELM2 domain. Deletion of Trsnt2 inhibited colony growth, reduced aerial hyphae, decreased polar growth, and increased hyphal branching of T. roseum. In addition, the deletion of Trsnt2 downregulated the expression of key genes related to sporulation, including TrbrlA, TrabaA, and TrwetA, reducing sporulation but increasing spore germination. The Trsnt2 deletion strain was more sensitive to cell wall stress and oxidative stress, but not to osmotic stress. In addition, Trsnt2 deletion downregulated the expression levels of PacC, ammonia synthesis-related genes (TrGDH2, TrAMET, TrGLT1, and TrMEPB), and extracellular enzyme-related genes (TrpelB, TrplyB, Trpme1, TrpgaX, TreglA, Trbgl1, Trcbh1, and Trcut1) in T. roseum. Deletion of Trsnt2 also reduced the pathogenicity of T. roseum on apple fruit. In conclusion, deletion of Trsnt2 inhibited the growth and development of T. roseum, reduced sensitivity of the strain to osmotic stress, but increased to cell wall and oxidative stress, and reduced the pathogenicity of the strain on apple fruit.

Root rot is one of the common diseases of Lycium barbarum. Pathogens can cause devastating disasters to plants after infecting host plants. This study investigated the effect of arbuscular mycorrhizal fungi (AMF) Rhizophagus intraradices inoculation on phenylpropane metabolism in L. barbarum and evaluated its resistance to root rot. The experiment was set up with AMF inoculation treatments (inoculated or not) and root rot pathogen-Fusarium solani inoculation treatments (inoculated or not). The results showed that AMF was able to form a symbiosis with the root system of L. barbarum, thereby promoting plant growth significantly and increasing plants’ resistance to disease stress. The plant height of AMF-colonized L. barbarum increased by 24.83% compared to non-inoculated diseased plants. After inoculation with AMF, the plant defense response induced by pathogen infection was stronger. When the enzyme activity of the leaves reached the maximum after the onset of mycorrhizal L. barbarum, phenylalanine ammonia-lyase, cinnamic acid-4-hydroxylase, and 4-coumaric acid-CoA ligase increased by 3.67%, 31.47%, and 13.61%, respectively, compared with the non-inoculated diseased plants. The products related to the lignin pathway and flavonoid pathway downstream of phenylpropane metabolism such as lignin and flavonoids were also significantly increased by 141.65% and 44.61% compared to nonmycorrhizal diseased plants. The activities of chitinase and β-1,3-glucanase increased by 36.00% and 57.96%, respectively. The contents of salicylic acid and jasmonic acid were also 17.7% and 31.63% higher than those of nonmycorrhizal plants in the early stage of plant growth, respectively. The results indicated that AMF significantly promoted plant growth and enhanced disease resistance by increasing enzyme activities and the production of lignin and flavonoids.

The Pal signaling pathway plays an important role in the adaptation of pathogenic fungi to environmental pH fluctuations and consists of PalA, PalB, PalC, PalF, PalI, PalH and Pac C in filamentous fungi. As a key regulator of the Pal signaling pathway, the transcription factor PacC is involved in the regulation of ammonia synthesis, extracellular enzyme activity and pathogenicity of fungi. However, the effect of PacC on the Pal signaling pathway and the production of reactive oxygen species (ROS) in fungi is unknown. It is also unclear whether PacC is involved in the synthesis and transport of ammonia, the alkalinization of environmental pH and the regulation of extracellular enzyme gene expression in Trichothecium roseum. In this study, the wild-type strain, ΔPacC mutant and ΔPacC-C complement strains of T. roseum were used as material to analyze the role of TrPacC in the Pal pathway, ammonia accumulation and environmental pH regulation. Meanwhile, the effect of TrPacC on the pathogenicity of T. roseum was investigated by determining the production of ROS and the expression of extracellular enzyme genes. The results showed that deletion of TrPacC enhanced the pH signal perception and transduction by upregulating the expression of TrPalF and TrPalH, but downregulated the expression of TrPalC, TrPalA and TrPalB, which are involved in PacC activation. Deletion of TrPacC inhibited ammonia synthesis and secretion by downregulating the expression of TrGDH2, TrAMET, TrMEPB and TrGLT1, resulting in reduced ammonia accumulation and attenuated alkalization ability at ambient pH in vivo and in vitro. Deletion of TrPacC also reduced superoxide anion and hydrogen peroxide levels by downregulating TrNoxA expression, but had no significant effect on TrNoxB expression. In addition, deletion of TrPacC downregulated the expression of TrPG, TrPMG, TrPME, TrPL, TrPAL and TrCx and inhibited the lesion expansion of T. roseum on muskmelon and apple fruit. Taken together, deletion of TrPacC attenuated the pathogenicity of T. roseum in muskmelon and apple fruit by reducing the accumulation of ammonia and ROS and inhibiting the expression of extracellular enzyme genes.

Fusarium solani is the main pathogenic fungus causing the root rot of wolfberry (Lycium barbarum). The endophytic fungus Metarhizium robertsii has been widely used for the biocontrol of plant pathogenic fungi, but the biocontrol effects of this fungus on wolfberry root rot and its antifungal mechanism against F. solani have not been reported. In this study, the antagonism of endophytic fungus M. robertsii against F. solani was verified. Further, we optimized the fermentation conditions of M. robertsii fermentation broth based on the inhibition rate of F. solani. In addition, the effects of M. robertsii fermentation broth on the root rot of wolfberry and its partial inhibition mechanism were investigated. The results showed that M. robertsii exhibited good antagonism against F. solani. Glucose and beef extracts were the optimal carbon and nitrogen sources for the fermentation of M. robertsii. Under the conditions of 29 °C, 190 rpm, and pH 7.0, the fermentation broth of M. robertsii had the best inhibition effect on F. solani. Furthermore, the fermentation broth treatment decreased the activities of superoxide dismutase, catalase, and peroxidase of F. solani; promoted the accumulation of malondialdehyde; and accelerated the leakage of soluble protein and the decrease in soluble sugar. In addition, inoculation with M. robertsii significantly reduced the decay incidence and disease index of wolfberry root rot caused by F. solani. These results indicate that M. robertsii could be used as a biological control agent in wolfberry root rot disease management.