Fruits from fig tree (Ficus carica L.) are economically important worldwide, and rank among the top 20 fruits exported by Brazil. However, due to particular features in its floral structure, classical plant breeding p...Fruits from fig tree (Ficus carica L.) are economically important worldwide, and rank among the top 20 fruits exported by Brazil. However, due to particular features in its floral structure, classical plant breeding procedures that involve hybridization are not possible. Thus, genetic improvement of figs by using mutagens is an important line of research. In this study, five fig selections based on their interesting agronomic features were used. Genetic modifications associated with mutations were not detected by molecular markers. Therefore, it was suggested that certain phenotypes could have resulted from epigenetic modifications. The best characterized epigenetic modification is DNA methylation, which can switch genes on or off by acting as a signal. After epigenetic polymorphisms were identified by methylation sensitive amplified polymorphism (MSAP) molecular markers, we quantified the level of DNA methylation in fig selections irradiated with gamma rays and compared it to levels in the commercial cultivar “Roxo-de-Valinhos.” This was achieved by analyzing the global methylation using an Imprint Methylated DNA Quantification kit. The results showed that there were significant differences in global methylation following different treatments, indicating that irradiation was an abiotic factor that could alter the epigenome of plants. Since the material used as a control was also found to be methylated, demethylation of the polymorphic genomic material might account for the phenotypic variations observed among different treatment groups. These results suggest that irradiation is an external factor that is capable of altering epigenetic patterns.展开更多
Inner bark extracts of Stryphnodendron adstringens, a leguminous tree species known as Barbatimão, are often incorporated to phytotherapic formulations due to their antimicrobial and healing activities. In ...Inner bark extracts of Stryphnodendron adstringens, a leguminous tree species known as Barbatimão, are often incorporated to phytotherapic formulations due to their antimicrobial and healing activities. In this study, extracts from S. adstringens accessions collected in 12 distinct locations were investigated in order to determine the rates of tannins in inner barks and to validate S. adstringens antibacterial and antifungal effectiveness. Yields of tannins were quantified by colorimetric assay following methodology described in the Brazilian Pharmacopoeia and the antimicrobial activity was determined by microdilution technique proposed by the National Committee for Clinical Laboratory Standards using S. adstringens hydroalcoholic and aqueous extracts and semi-purified fractions. Investigated extracts did not present significant antibacterial activity though aqueous extracts exhibited antifungal effect against both Trichophyton rubrum mutant and clinical strains (MIC 156 μg/mL). A positive correlation between tannin concentration and antifungal activity was observed and the accessions collected in Delfinópolis (MG) were considered elite.展开更多
文摘Fruits from fig tree (Ficus carica L.) are economically important worldwide, and rank among the top 20 fruits exported by Brazil. However, due to particular features in its floral structure, classical plant breeding procedures that involve hybridization are not possible. Thus, genetic improvement of figs by using mutagens is an important line of research. In this study, five fig selections based on their interesting agronomic features were used. Genetic modifications associated with mutations were not detected by molecular markers. Therefore, it was suggested that certain phenotypes could have resulted from epigenetic modifications. The best characterized epigenetic modification is DNA methylation, which can switch genes on or off by acting as a signal. After epigenetic polymorphisms were identified by methylation sensitive amplified polymorphism (MSAP) molecular markers, we quantified the level of DNA methylation in fig selections irradiated with gamma rays and compared it to levels in the commercial cultivar “Roxo-de-Valinhos.” This was achieved by analyzing the global methylation using an Imprint Methylated DNA Quantification kit. The results showed that there were significant differences in global methylation following different treatments, indicating that irradiation was an abiotic factor that could alter the epigenome of plants. Since the material used as a control was also found to be methylated, demethylation of the polymorphic genomic material might account for the phenotypic variations observed among different treatment groups. These results suggest that irradiation is an external factor that is capable of altering epigenetic patterns.
基金We thank the Fundacao de Amparo à Pesquisa do Estado de São Paulo(FAPESP)for financial support(Process:2008/00762-02008/10499-4) to Professor Nilce M.Martinez-Rossi for kindly providing the T.rubrum mu-tant strain.
文摘Inner bark extracts of Stryphnodendron adstringens, a leguminous tree species known as Barbatimão, are often incorporated to phytotherapic formulations due to their antimicrobial and healing activities. In this study, extracts from S. adstringens accessions collected in 12 distinct locations were investigated in order to determine the rates of tannins in inner barks and to validate S. adstringens antibacterial and antifungal effectiveness. Yields of tannins were quantified by colorimetric assay following methodology described in the Brazilian Pharmacopoeia and the antimicrobial activity was determined by microdilution technique proposed by the National Committee for Clinical Laboratory Standards using S. adstringens hydroalcoholic and aqueous extracts and semi-purified fractions. Investigated extracts did not present significant antibacterial activity though aqueous extracts exhibited antifungal effect against both Trichophyton rubrum mutant and clinical strains (MIC 156 μg/mL). A positive correlation between tannin concentration and antifungal activity was observed and the accessions collected in Delfinópolis (MG) were considered elite.
