Plant-derived essential oils have excellent antifungal effects and can be used for the preservation of fresh foods such as fruits and vegetables, but the detailed mechanism has not been fully elucidated. In this study...Plant-derived essential oils have excellent antifungal effects and can be used for the preservation of fresh foods such as fruits and vegetables, but the detailed mechanism has not been fully elucidated. In this study, we investigated the inhibitory effects of trans-cinnamaldehyde on Penicillium italicum, a common pollution fungus in citrus, and explored the antifungal mechanism of trans-cinnamaldehyde by detecting fungal oxidative damage, mitochondrial metabolism, and cell apoptosis. These results showed that transcinnamaldehyde made the carboxylic acid cycle deregulated by altering the related enzyme activities(succinate dehydrogenase, malate dehydrogenase) and mid product. Moreover, the level of reactive oxygen species rose sharply while the redox level was out of regulation. The mitochondrial membrane potential collapsed, leading to the leakage of cytochrome c, and then triggering the activation of apoptotic protease, which was further confirmed by the significant increase in caspase-3 activity from(3.6 ± 0.6) U to(8.8 ± 1.1) U(P < 0.05). The cytochrome c in mitochondria was detected by confocal Raman microspectroscopy, the characteristic intensity index(I750/I2944) was decreased, indicating that the cytochrome c in mitochondria was reduced and leakage. Besides, the strong negative correlation between Raman intensity and the amount of cytochrome c leakage was established with the correlation coefficient of-0.981 7. This study revealed that destroying the integrity of the mitochondrial membrane, activating the mitochondrial-mediated apoptosis pathway was the in-depth antifungal mechanism of trans-cinnamaldehyde;and Raman spectroscopy technology provided new ideas to study this process with high sensitivity determination of cytochrome c.展开更多
Penicillium italicum is the causal agent of citrus blue mold,which is a major threat to the global citrus fruit industry.Antofine,a natural phenanthroindolizidine alkaloid,is water-soluble and exhibits a broad range o...Penicillium italicum is the causal agent of citrus blue mold,which is a major threat to the global citrus fruit industry.Antofine,a natural phenanthroindolizidine alkaloid,is water-soluble and exhibits a broad range of biological activities.However,whether it can inhibit P italicum growth and the potential inhibitory mechanism remains to be elucidated.This study aimed to investigate the antifungal mechanism of antofine against P italicum using scanning electron microscopy,transmission electron microscopy(TEM),propidium iodide staining,and tandem mass tag-labeled quantitative proteomic analysis.Antofine was found to exhibit its preeminent antifungal activity against P italicum with a minimum inhibitory concentration of 1.56 mg/L and a minimum fungicidal concentration of 6.25 mg/L.The challenge test revealed that antofine inhibited the development of citrus blue mold during a 6-d P italicum-infected period.Antofine acted on its potential multitargets to inhibit P italicum growth by synergistically activating oxidative stress through accumulating excess reactive oxygen species,impairing membrane integrity.inducing membrane lipid peroxidation,and disrupting mitochondrial function,thereby disrupting the membrane system and reducing cell via-bility.Moreover,antofine treatment downregulated most differentially expressed proteins involved in carbon metabolism,pyruvate metabolism,and the tricarboxylic acid cycle(TCA)in P italicum mycelia,which may explain the mitochondrial decomposition observed by TEM and the de-clines in ATP levels as well as the activities of TCA-related enzymes.These results indicate that antofine treatment inhibited P italicum growth by targeting the cell membrane and mitochondria.展开更多
Mycoviruses have been found to infect more than 12 species of Penicillium, but have not been isolated from Penicillium italicum(P. italicum). In this study, we isolated and characterized a new double-stranded RNA(ds R...Mycoviruses have been found to infect more than 12 species of Penicillium, but have not been isolated from Penicillium italicum(P. italicum). In this study, we isolated and characterized a new double-stranded RNA(ds RNA) virus, designated Penicillium italicum chrysovirus 1(Pi CV1), from the citrus pathogen P. italicum HSPi-YN1. Viral genome sequencing and molecular characterization indicated that Pi CV1 was highly homologous to the previously described Penicillium chrysogenum virus. We further constructed the mutant HSPi-YN1 Dpks P defective in the polyketide synthase gene(pks P), which is involved in pigment biosynthesis, and these mutants formed albino(white) colonies. Then we applied hyphal anastomosis method to horizontally transmit Pi CV1 from the white virus-donors(i.e., HSPi-YN1 mutants) to wild-type recipients(i.e., P.italicum strains HSPi-CQ54, HSPi-HB4, and HSPi-HN1), and the desirable Pi CV1-infected isogenic recipients, a certain part of blue wild-type strains, can be eventually selected and confirmed by viral genomic ds RNA profile analysis. This bluewhite colony screening would be an easier method to select virus-infected P. italicum recipients, according to distinguishable color phenotypes between blue virus-recipients and white virus-donors. In summary, the current work newly isolated and characterized Pi CV1, verified its horizontal transmission among dually cultured P. italicum isolates, and based on these, established an effective and simplified approach to screen Pi CV1-infected isogenic recipients.展开更多
Postharvest pathogens can affect a wide range of fresh fruit and vegetables,including grapes,resulting in significant profit loss.Isoquinoline alkaloids of Mahonia fortunei,a Chinese herbal medicine,have been used to ...Postharvest pathogens can affect a wide range of fresh fruit and vegetables,including grapes,resulting in significant profit loss.Isoquinoline alkaloids of Mahonia fortunei,a Chinese herbal medicine,have been used to treat infectious microbes,which might be effective against postharvest pathogens.The phytochemical and bioactive investigation of this plant led to the isolation of 18 alkaloids,of which 9 compounds inhibited the growth of Botrytis cinerea and 4 compounds against Penicillium italicum.The antifungal alkaloids could change the mycelium morphology,the total lipid content,and leak the cell contents of B.cinerea.Furthermore,the two most potent antifungal alkaloids,berber-ine(13)completely inhibited effect on gray mold of table grape at 512 mg L^(−1),while jatrorrhizine(18)exhibited an inhibition rate>90%on grape rot at the same concentration,with lower cytotoxicity and residue than chlorothalonil,which suggested that ingredients of M.fortunei might be a low-toxicity,low-residue,eco-friendly botanical fungicide against postharvest pathogens.展开更多
基金supported by China Postdoctoral Science Foundation (2020M680064)National Natural Science Foundation of China (32172326)the Postdoctoral Research Startup Fee of Jiangnan University (1025219032200190)。
文摘Plant-derived essential oils have excellent antifungal effects and can be used for the preservation of fresh foods such as fruits and vegetables, but the detailed mechanism has not been fully elucidated. In this study, we investigated the inhibitory effects of trans-cinnamaldehyde on Penicillium italicum, a common pollution fungus in citrus, and explored the antifungal mechanism of trans-cinnamaldehyde by detecting fungal oxidative damage, mitochondrial metabolism, and cell apoptosis. These results showed that transcinnamaldehyde made the carboxylic acid cycle deregulated by altering the related enzyme activities(succinate dehydrogenase, malate dehydrogenase) and mid product. Moreover, the level of reactive oxygen species rose sharply while the redox level was out of regulation. The mitochondrial membrane potential collapsed, leading to the leakage of cytochrome c, and then triggering the activation of apoptotic protease, which was further confirmed by the significant increase in caspase-3 activity from(3.6 ± 0.6) U to(8.8 ± 1.1) U(P < 0.05). The cytochrome c in mitochondria was detected by confocal Raman microspectroscopy, the characteristic intensity index(I750/I2944) was decreased, indicating that the cytochrome c in mitochondria was reduced and leakage. Besides, the strong negative correlation between Raman intensity and the amount of cytochrome c leakage was established with the correlation coefficient of-0.981 7. This study revealed that destroying the integrity of the mitochondrial membrane, activating the mitochondrial-mediated apoptosis pathway was the in-depth antifungal mechanism of trans-cinnamaldehyde;and Raman spectroscopy technology provided new ideas to study this process with high sensitivity determination of cytochrome c.
基金funded by the National Natural Science Foundation of China(Nos.32002104 and 32060703)the Jiangxi Provincial Natural Science Foundation of China(No.20212BAB205011).
文摘Penicillium italicum is the causal agent of citrus blue mold,which is a major threat to the global citrus fruit industry.Antofine,a natural phenanthroindolizidine alkaloid,is water-soluble and exhibits a broad range of biological activities.However,whether it can inhibit P italicum growth and the potential inhibitory mechanism remains to be elucidated.This study aimed to investigate the antifungal mechanism of antofine against P italicum using scanning electron microscopy,transmission electron microscopy(TEM),propidium iodide staining,and tandem mass tag-labeled quantitative proteomic analysis.Antofine was found to exhibit its preeminent antifungal activity against P italicum with a minimum inhibitory concentration of 1.56 mg/L and a minimum fungicidal concentration of 6.25 mg/L.The challenge test revealed that antofine inhibited the development of citrus blue mold during a 6-d P italicum-infected period.Antofine acted on its potential multitargets to inhibit P italicum growth by synergistically activating oxidative stress through accumulating excess reactive oxygen species,impairing membrane integrity.inducing membrane lipid peroxidation,and disrupting mitochondrial function,thereby disrupting the membrane system and reducing cell via-bility.Moreover,antofine treatment downregulated most differentially expressed proteins involved in carbon metabolism,pyruvate metabolism,and the tricarboxylic acid cycle(TCA)in P italicum mycelia,which may explain the mitochondrial decomposition observed by TEM and the de-clines in ATP levels as well as the activities of TCA-related enzymes.These results indicate that antofine treatment inhibited P italicum growth by targeting the cell membrane and mitochondria.
基金supported by the National Natural Science Foundations of China (No. 31371893)the Natural Science Fund of Hubei Province (No. 2018CFB676)the Project of Hubei Key Laboratory of Genetic Regulation and Integrative Biology (Grant No. GRIB20184)
文摘Mycoviruses have been found to infect more than 12 species of Penicillium, but have not been isolated from Penicillium italicum(P. italicum). In this study, we isolated and characterized a new double-stranded RNA(ds RNA) virus, designated Penicillium italicum chrysovirus 1(Pi CV1), from the citrus pathogen P. italicum HSPi-YN1. Viral genome sequencing and molecular characterization indicated that Pi CV1 was highly homologous to the previously described Penicillium chrysogenum virus. We further constructed the mutant HSPi-YN1 Dpks P defective in the polyketide synthase gene(pks P), which is involved in pigment biosynthesis, and these mutants formed albino(white) colonies. Then we applied hyphal anastomosis method to horizontally transmit Pi CV1 from the white virus-donors(i.e., HSPi-YN1 mutants) to wild-type recipients(i.e., P.italicum strains HSPi-CQ54, HSPi-HB4, and HSPi-HN1), and the desirable Pi CV1-infected isogenic recipients, a certain part of blue wild-type strains, can be eventually selected and confirmed by viral genomic ds RNA profile analysis. This bluewhite colony screening would be an easier method to select virus-infected P. italicum recipients, according to distinguishable color phenotypes between blue virus-recipients and white virus-donors. In summary, the current work newly isolated and characterized Pi CV1, verified its horizontal transmission among dually cultured P. italicum isolates, and based on these, established an effective and simplified approach to screen Pi CV1-infected isogenic recipients.
基金NSFC,32170405,Xiao-Dong Luothe High-level Talent Promotion and Training Project of Kunming,2022SCP003,Xiao-Dong Luo+1 种基金Project of Yunnan Characteristic Plant Screening and R&D Service CXO Platform,2022YKZY001,Xiao-Dong LuoScientific and Technological Innovation Team of Yunnan Province,202105AE160006,Xiao-Dong Luo.
文摘Postharvest pathogens can affect a wide range of fresh fruit and vegetables,including grapes,resulting in significant profit loss.Isoquinoline alkaloids of Mahonia fortunei,a Chinese herbal medicine,have been used to treat infectious microbes,which might be effective against postharvest pathogens.The phytochemical and bioactive investigation of this plant led to the isolation of 18 alkaloids,of which 9 compounds inhibited the growth of Botrytis cinerea and 4 compounds against Penicillium italicum.The antifungal alkaloids could change the mycelium morphology,the total lipid content,and leak the cell contents of B.cinerea.Furthermore,the two most potent antifungal alkaloids,berber-ine(13)completely inhibited effect on gray mold of table grape at 512 mg L^(−1),while jatrorrhizine(18)exhibited an inhibition rate>90%on grape rot at the same concentration,with lower cytotoxicity and residue than chlorothalonil,which suggested that ingredients of M.fortunei might be a low-toxicity,low-residue,eco-friendly botanical fungicide against postharvest pathogens.
