Dihydrochelerythrine(DHCHE)is an isoquinoline compound,which has distinct antifungal activity and can induce apoptosis.The antifungal activity of DHCHE against five rice pathogenic fungi was studied in vitro.At the co...Dihydrochelerythrine(DHCHE)is an isoquinoline compound,which has distinct antifungal activity and can induce apoptosis.The antifungal activity of DHCHE against five rice pathogenic fungi was studied in vitro.At the concentration of 7.5 mg/L,DHCHE exhibited the highest efficacy among tested compounds in inhibiting mycelium growth,with an inhibition rate of 68.8%in Ustilaginoidea virens,which was approximately 2.4 times of that of validamycin(28.7%).After exposure to DHCHE,transmission electron micrographs revealed spores showed incomplete organelles,malformed cell walls and nuclear membranes,as well as irregular lipid spheres.Reactive oxygen species accumulation in treated spores was markedly higher than that in control spores.DHCHE induced cell damage increased in a dose-dependent manner,as indicated by the decrease in mitochondrial membrane potential and initiation of apoptosis.The differences of expression levels of Fip1,ACP1,PMS2 and COX13 that are important for oxidative phosphorylation and mismatch repair pathway were significant,which may be some of the reasons for the induction of apoptosis in DHCHE-treated U.virens.The protein levels of Fip1,ACP1,PMS2 and COX13 agreed with protein fold change ratio from parallel reaction monitoring Gene Ontology terms and Kyoto Encyclopedia of Genes and Genomes pathway of differentially expressed proteins were further analyzed.These findings will help to elucidate the mechanisms associated with antifungal and pro-apoptotic effects of DHCHE on U.virens,thereby aiding the potential development of novel pesticides.展开更多
[ Objective] The paper was to study pathogenic mechanism and action mode of Bacillus thuringiensis （Bt） 00-50-5 strain against Trichoplusia ni Hub- ner. [Method] The crystals and spores of B. thuringiensis 00-50-5 s...[ Objective] The paper was to study pathogenic mechanism and action mode of Bacillus thuringiensis （Bt） 00-50-5 strain against Trichoplusia ni Hub- ner. [Method] The crystals and spores of B. thuringiensis 00-50-5 strain were first isolated and purified, and their insecticidal activities against T. ni were com- pared. [ Result] Either the mixture of pure crystals and pure spores of 00-50-5 strain, or only pure crystals could kill T. n/larvae under the concentration of 100 p.g/mL after 48 h, and the mortality rate reached 100% ; pure spores could not kill the larvae. Determination results of median lethal concentration showed that in- secticidal activity of pure crystal of Bt 00-50-5 strain （LGs0 =0.32 p~/mL） was higher than the mixture of crystals and spores （LCs0 =0.48）, but the insecticidal acti^ty of pure spores was very low （LC50 〉 500.00）. Therefore, the crystals were primarily responsible for causing death of larvae. [ Conclusion] The paper provides theoretical basis for application of Bt 00-50-5 strain.展开更多
基金financially supported by the National Natural Science Foundation of China(Grant No.51678120).
文摘Dihydrochelerythrine(DHCHE)is an isoquinoline compound,which has distinct antifungal activity and can induce apoptosis.The antifungal activity of DHCHE against five rice pathogenic fungi was studied in vitro.At the concentration of 7.5 mg/L,DHCHE exhibited the highest efficacy among tested compounds in inhibiting mycelium growth,with an inhibition rate of 68.8%in Ustilaginoidea virens,which was approximately 2.4 times of that of validamycin(28.7%).After exposure to DHCHE,transmission electron micrographs revealed spores showed incomplete organelles,malformed cell walls and nuclear membranes,as well as irregular lipid spheres.Reactive oxygen species accumulation in treated spores was markedly higher than that in control spores.DHCHE induced cell damage increased in a dose-dependent manner,as indicated by the decrease in mitochondrial membrane potential and initiation of apoptosis.The differences of expression levels of Fip1,ACP1,PMS2 and COX13 that are important for oxidative phosphorylation and mismatch repair pathway were significant,which may be some of the reasons for the induction of apoptosis in DHCHE-treated U.virens.The protein levels of Fip1,ACP1,PMS2 and COX13 agreed with protein fold change ratio from parallel reaction monitoring Gene Ontology terms and Kyoto Encyclopedia of Genes and Genomes pathway of differentially expressed proteins were further analyzed.These findings will help to elucidate the mechanisms associated with antifungal and pro-apoptotic effects of DHCHE on U.virens,thereby aiding the potential development of novel pesticides.
基金supported by Project for Introduced Talents in Environment and Plant Protection Institute of Chinese Academy of Tropical Agriculture(HZS1101)Fundamental Research Special Project for Central Public-interest Scientific Institutes(2012hzs1 J038,2012hzs1 J016)
文摘[ Objective] The paper was to study pathogenic mechanism and action mode of Bacillus thuringiensis （Bt） 00-50-5 strain against Trichoplusia ni Hub- ner. [Method] The crystals and spores of B. thuringiensis 00-50-5 strain were first isolated and purified, and their insecticidal activities against T. ni were com- pared. [ Result] Either the mixture of pure crystals and pure spores of 00-50-5 strain, or only pure crystals could kill T. n/larvae under the concentration of 100 p.g/mL after 48 h, and the mortality rate reached 100% ; pure spores could not kill the larvae. Determination results of median lethal concentration showed that in- secticidal activity of pure crystal of Bt 00-50-5 strain （LGs0 =0.32 p~/mL） was higher than the mixture of crystals and spores （LCs0 =0.48）, but the insecticidal acti^ty of pure spores was very low （LC50 〉 500.00）. Therefore, the crystals were primarily responsible for causing death of larvae. [ Conclusion] The paper provides theoretical basis for application of Bt 00-50-5 strain.
