RESUMO
Camptothecin and its derivatives are monoterpenoid indole alkaloids exhibiting significant anti-tumor actions. With the aim of improving the production of these pharmaceuticals, the contents of camptothecin and 10-hydroxycamptothecin in different tissues including roots, stems, leaves, young flower buds, opening flowers, fading flowers and seeds from Camptotheca acuminata, were investigated. The young flower buds had the highest alkaloid concentrations (camptothecin, 2.46 mg/g of dry weight; 10-hydroxycamptothecin, 1.41 mg/g of dry weight). Callus showed lower concentrations but it should also be considered as a potential source of these pharmaceuticals. In the present study, the growth rate of Camptotheca acuminata cells in culture did not correlate with contents of camptothecin and 10-hydroxycamptothecin. Alkalo id accumulation by cells under various treatments (heavy metal ions, UV-B), methyl-jasmonate, abscisic acid, salicylic acid and hydrogen peroxide was examined, and the most notable effects appeared in the cells induced by UV-B light (which showed an 11-fold increase in camptothecin concentration) and by salicylic acid (which showed a 25-fold increase in 10-hydroxycamptothecin concentration). These results are significant in the context of the production of both pharmaceuticals.
Assuntos
Antineoplásicos Fitogênicos/isolamento & purificação , Alcaloides/isolamento & purificação , Camptotecina/análogos & derivados , Camptotecina/isolamento & purificação , Camptotheca/citologia , Camptotheca/crescimento & desenvolvimento , Camptotheca/química , Meios de Cultura , Medicamentos de Ervas Chinesas/isolamento & purificação , Técnicas de Cultura de Células/métodosRESUMO
Camptothecin and its derivatives are monoterpenoid indole alkaloids exhibiting significant anti-tumor actions. With the aim of improving the production of these pharmaceuticals, the contents of camptothecin and 10-hydroxycamptothecin in different tissues including roots, stems, leaves, young flower buds, opening flowers, fading flowers and seeds from Camptotheca acuminata, were investigated. The young flower buds had the highest alkaloid concentrations (camptothecin, 2.46 mg/g of dry weight; 10-hydroxycamptothecin, 1.41 mg/g of dry weight). Callus showed lower concentrations but it should also be considered as a potential source of these pharmaceuticals. In the present study, the growth rate of Camptotheca acuminata cells in culture did not correlate with contents of camptothecin and 10-hydroxycamptothecin. Alkalo id accumulation by cells under various treatments (heavy metal ions, UV-B), methyl-jasmonate, abscisic acid, salicylic acid and hydrogen peroxide was examined, and the most notable effects appeared in the cells induced by UV-B light (which showed an 11-fold increase in camptothecin concentration) and by salicylic acid (which showed a 25-fold increase in 10-hydroxycamptothecin concentration). These results are significant in the context of the production of both pharmaceuticals.(AU)
Assuntos
Alcaloides/isolamento & purificação , Camptotheca/química , Camptotheca/citologia , Camptotheca/crescimento & desenvolvimento , Antineoplásicos Fitogênicos/isolamento & purificação , Camptotecina/análogos & derivados , Camptotecina/isolamento & purificação , Técnicas de Cultura de Células/métodos , Meios de Cultura , Medicamentos de Ervas Chinesas/isolamento & purificaçãoRESUMO
A gene encoding a mannose-binding lectin, Pinellia pedatisecta agglutinin (PPA), was isolated from leaves of Pinellia pedatisecta using genomic walker technology. The ppa contained an 1140-bp 5'-upstream region, a 771-bp open reading frame (ORF) and an 829-bp 3'-downstream region. The ORF encoded a precursor polypeptide of 256 amino acid residues with a 24-amino acid signal peptide. There were one putative TATA box and six possible CAAT boxes lying in the 5'-upstream region of ppa. The ppa showed significant similarity at the nucleic acid level with genes encoding mannose-binding lectins from other Araceae species such as Pinellia ternata, Arisaema heterophyllum, Colocasia esculenta and Arum maculatum. At the amino acid level, PPA also shared varying homology (ranging from 40% to 85%) with mannose-binding lectins from other plant species, such as those from Araceae, Alliaceae, Iridaceae, Lillaceae, Amaryllidaceae and Bromeliaceae. The cloning of the ppa gene not only provides a basis for further investigation of PPA's structure, expression and regulation mechanism, but also enables us to test its potential role in controlling pests and fungal diseases by transferring the gene into tobacco and rice in the future
Assuntos
Clonagem Molecular , DNA de Plantas , Genes de Plantas/genética , Lectina de Ligação a Manose/genética , Conformação Proteica , Pinellia/genética , Dados de Sequência Molecular , Lectinas de PlantasRESUMO
A gene encoding a mannose-binding lectin, Pinellia pedatisecta agglutinin (PPA), was isolated from leaves of Pinellia pedatisecta using genomic walker technology. The ppa contained an 1140-bp 5-upstream region, a 771-bp open reading frame (ORF) and an 829-bp 3-downstream region. The ORF encoded a precursor polypeptide of 256 amino acid residues with a 24-amino acid signal peptide. There were one putative TATA box and six possible CAAT boxes lying in the 5-upstream region of ppa. The ppa showed significant similarity at the nucleic acid level with genes encoding mannose-binding lectins from other Araceae species such as Pinellia ternata, Arisaema heterophyllum, Colocasia esculenta and Arum maculatum. At the amino acid level, PPA also shared varying homology (ranging from 40% to 85%) with mannose-binding lectins from other plant species, such as those from Araceae, Alliaceae, Iridaceae, Lillaceae, Amaryllidaceae and Bromeliaceae. The cloning of the ppa gene not only provides a basis for further investigation of PPAs structure, expression and regulation mechanism, but also enables us to test its potential role in controlling pests and fungal diseases by transferring the gene into tobacco and rice in the future(AU)
Assuntos
Clonagem Molecular , Lectina de Ligação a Manose/genética , Pinellia/genética , DNA de Plantas/genética , Genes de Plantas/genética , Conformação Proteica , Lectinas de Plantas/genética , Dados de Sequência MolecularRESUMO
A gene encoding a mannose-binding lectin, Pinellia pedatisecta agglutinin (PPA), was isolated from leaves of Pinellia pedatisecta using genomic walker technology. The ppa contained an 1140-bp 5-upstream region, a 771-bp open reading frame (ORF) and an 829-bp 3-downstream region. The ORF encoded a precursor polypeptide of 256 amino acid residues with a 24-amino acid signal peptide. There were one putative TATA box and six possible CAAT boxes lying in the 5-upstream region of ppa. The ppa showed significant similarity at the nucleic acid level with genes encoding mannose-binding lectins from other Araceae species such as Pinellia ternata, Arisaema heterophyllum, Colocasia esculenta and Arum maculatum. At the amino acid level, PPA also shared varying homology (ranging from 40% to 85%) with mannose-binding lectins from other plant species, such as those from Araceae, Alliaceae, Iridaceae, Lillaceae, Amaryllidaceae and Bromeliaceae. The cloning of the ppa gene not only provides a basis for further investigation of PPAs structure, expression and regulation mechanism, but also enables us to test its potential role in controlling pests and fungal diseases by transferring the gene into tobacco and rice in the future(AU)
Assuntos
Clonagem Molecular , Lectina de Ligação a Manose/genética , Pinellia/genética , DNA de Plantas/genética , Genes de Plantas/genética , Conformação Proteica , Lectinas de Plantas/genética , Dados de Sequência MolecularRESUMO
Using RNA extracted from Zantedeschia aethiopica young leaves and primers designed according to the conservative regions of Araceae lectins, the full-length cDNA of Z. aethiopica agglutinin (ZAA) was cloned by rapid amplification of cDNA ends (RACE). The full-length cDNA of zaa was 871 bp and contained a 417 bp open reading frame (ORF) encoding a lectin precursor of 138 amino acids. Through comparative analysis of zaa gene and its deduced amino acid sequence with those of other Araceae species, it was found that zaa encoded a precursor lectin with signal peptide. Secondary and three-dimensional structure analyses showed that ZAA had many common characters of mannose-binding lectin superfamily and ZAA was a mannose-binding lectin with three mannose-binding sites. Southern blot analysis of the genomic DNA revealed that zaa belonged to a multi-copy gene family
Assuntos
Lectina de Ligação a Manose/fisiologia , Lectina de Ligação a Manose/genética , Lectina de Ligação a Manose/química , Lectina de Ligação a Manose , Proteínas de Plantas/fisiologia , Proteínas de Plantas/genética , Proteínas de Plantas/química , Genes de Plantas/fisiologia , Genes de Plantas/genética , Plantas Geneticamente Modificadas/fisiologia , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/química , Regulação da Expressão Gênica de Plantas/fisiologia , Regulação da Expressão Gênica de Plantas/genéticaRESUMO
Using RNA extracted from Zantedeschia aethiopica young leaves and primers designed according to the conservative regions of Araceae lectins, the full-length cDNA of Z. aethiopica agglutinin (ZAA) was cloned by rapid amplification of cDNA ends (RACE). The full-length cDNA of zaa was 871 bp and contained a 417 bp open reading frame (ORF) encoding a lectin precursor of 138 amino acids. Through comparative analysis of zaa gene and its deduced amino acid sequence with those of other Araceae species, it was found that zaa encoded a precursor lectin with signal peptide. Secondary and three-dimensional structure analyses showed that ZAA had many common characters of mannose-binding lectin superfamily and ZAA was a mannose-binding lectin with three mannose-binding sites. Southern blot analysis of the genomic DNA revealed that zaa belonged to a multi-copy gene family
Assuntos
Lectina de Ligação a Manose , Lectina de Ligação a Manose/química , Lectina de Ligação a Manose/genética , Lectina de Ligação a Manose/fisiologia , Proteínas de Plantas/fisiologia , Proteínas de Plantas/química , Proteínas de Plantas/genética , Plantas Geneticamente Modificadas/química , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/fisiologia , Regulação da Expressão Gênica de Plantas/genética , Regulação da Expressão Gênica de Plantas/fisiologia , Genes de Plantas/genética , Genes de Plantas/fisiologiaRESUMO
Using RNA extracted from Zantedeschia aethiopica young leaves and primers designed according to the conservative regions of Araceae lectins, the full-length cDNA of Z. aethiopica agglutinin (ZAA) was cloned by rapid amplification of cDNA ends (RACE). The full-length cDNA of zaa was 871 bp and contained a 417 bp open reading frame (ORF) encoding a lectin precursor of 138 amino acids. Through comparative analysis of zaa gene and its deduced amino acid sequence with those of other Araceae species, it was found that zaa encoded a precursor lectin with signal peptide. Secondary and three-dimensional structure analyses showed that ZAA had many common characters of mannose-binding lectin superfamily and ZAA was a mannose-binding lectin with three mannose-binding sites. Southern blot analysis of the genomic DNA revealed that zaa belonged to a multi-copy gene family.