This study investigated the antifungal activity and possible mode of action of Bacillus pumilus HN-10 antifungal peptide P-1 against Trichothecium roseum.The results showed that the antifungal peptide P-1 at a concent...This study investigated the antifungal activity and possible mode of action of Bacillus pumilus HN-10 antifungal peptide P-1 against Trichothecium roseum.The results showed that the antifungal peptide P-1 at a concentration of 1.0μg mL^(-1)had strong antifungal activity against T.roseum.P-1 inhibited the tricarboxylic acid cycle(TCA)pathway and the transporter pathway of NADH to coenzyme Q on the electron transport chain.P-1 significantly reduced succinate dehydrogenase(SDH),malate dehydrogenase(MDH),ATPase,mitochondrial complex enzymes I,II and IV enzyme activities on the electron transport chain,and 5'-triphosphate(ATP),5'-diphosphate(ADP),5'-monophosphate(AMP)content,and energy charge(EC);significantly increased 6-phosphofructokinase(PFK)enzyme activity.The release of Ca^(2+)(OD_(680))from the inner mitochondrial membrane and the openness of the mitochondrial permeability transition pore(MPTP)were analysed,and microscopy was performed following staining of mitochondria with JC-1.The results indicated that P-1 significantly increased the release of Ca^(2+) and the openness of MPTP,decreased the mitochondrial membrane potential,and produced green fluorescence;transcriptomics data analysis showed that there were 39 differentially expressed genes(DEGs)related to energy metabolism enzymes.The results verified by qRT-PCR were basically consistent with the transcriptome sequencing results.Thus,P-1 achieved its inhibitory effect mainly by regulating genes related to energy metabolism.展开更多
Preharvest and postharvest application of Harpin was evaluated for its ability to induce resistance in muskmelon fruit and control rots. Preharvest treatments were 30 mg L^-1, 60 mg L^-1 Harpin or 1 mg L^-1 Imazalil e...Preharvest and postharvest application of Harpin was evaluated for its ability to induce resistance in muskmelon fruit and control rots. Preharvest treatments were 30 mg L^-1, 60 mg L^-1 Harpin or 1 mg L^-1 Imazalil either I week or I day before harvest. The CK was untreated. Fruit were then inoculated with Fusarium semitectum or Trichothecium roseum 48 h after harvest, and stored at 23± 1℃, RH （relative humidity） 50-60% for 4 d. All treatments were effective in reducing the lesion area with 60 mg L^-1 Harpin the most effectively. No treatments inhibited infection rate. Postharvest treatment was fruit dips of 30 mg L i, 60 mg L^-1 Harpin, 0.1 mg L i Imazalil. Fruit were inoculated with F. semitectum or T. roseum 24, 72, 120 or 168 h after treatment, and stored at 23 ± 1℃, RH 50-60% for 4 days. All treatments were effective in reducing the lesion area with 60 mg L^-1 Harpin the most effectively. No treatments inhibited the infection rate. Postharvest Harpin treatment induced the peroxidase activity increase, peroxidase activity reached maximum after 8 d and the activation lasted at least 10 d.展开更多
基金financially supported by National Key R&D Program of China(2018YFD0400205).
文摘This study investigated the antifungal activity and possible mode of action of Bacillus pumilus HN-10 antifungal peptide P-1 against Trichothecium roseum.The results showed that the antifungal peptide P-1 at a concentration of 1.0μg mL^(-1)had strong antifungal activity against T.roseum.P-1 inhibited the tricarboxylic acid cycle(TCA)pathway and the transporter pathway of NADH to coenzyme Q on the electron transport chain.P-1 significantly reduced succinate dehydrogenase(SDH),malate dehydrogenase(MDH),ATPase,mitochondrial complex enzymes I,II and IV enzyme activities on the electron transport chain,and 5'-triphosphate(ATP),5'-diphosphate(ADP),5'-monophosphate(AMP)content,and energy charge(EC);significantly increased 6-phosphofructokinase(PFK)enzyme activity.The release of Ca^(2+)(OD_(680))from the inner mitochondrial membrane and the openness of the mitochondrial permeability transition pore(MPTP)were analysed,and microscopy was performed following staining of mitochondria with JC-1.The results indicated that P-1 significantly increased the release of Ca^(2+) and the openness of MPTP,decreased the mitochondrial membrane potential,and produced green fluorescence;transcriptomics data analysis showed that there were 39 differentially expressed genes(DEGs)related to energy metabolism enzymes.The results verified by qRT-PCR were basically consistent with the transcriptome sequencing results.Thus,P-1 achieved its inhibitory effect mainly by regulating genes related to energy metabolism.
基金This study was supported by grants from Australia Center for International Agricultural Research(PHT/1998/140)M inistry of Science and Technology of China(2001BA501A09).
文摘Preharvest and postharvest application of Harpin was evaluated for its ability to induce resistance in muskmelon fruit and control rots. Preharvest treatments were 30 mg L^-1, 60 mg L^-1 Harpin or 1 mg L^-1 Imazalil either I week or I day before harvest. The CK was untreated. Fruit were then inoculated with Fusarium semitectum or Trichothecium roseum 48 h after harvest, and stored at 23± 1℃, RH （relative humidity） 50-60% for 4 d. All treatments were effective in reducing the lesion area with 60 mg L^-1 Harpin the most effectively. No treatments inhibited infection rate. Postharvest treatment was fruit dips of 30 mg L i, 60 mg L^-1 Harpin, 0.1 mg L i Imazalil. Fruit were inoculated with F. semitectum or T. roseum 24, 72, 120 or 168 h after treatment, and stored at 23 ± 1℃, RH 50-60% for 4 days. All treatments were effective in reducing the lesion area with 60 mg L^-1 Harpin the most effectively. No treatments inhibited the infection rate. Postharvest Harpin treatment induced the peroxidase activity increase, peroxidase activity reached maximum after 8 d and the activation lasted at least 10 d.
