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Gabriella Pasqua – 1st expert on this subject based on the ideXlab platform
trichomes in Camptotheca acuminata decaisne nyssaceae morphology distribution structure and secretionPlant Biosystems, 2013Co-Authors: Alessio Valletta, Anna Rita Santamaria, Antonella Canini, Lorena Canuti, Gabriella PasquaAbstract:
Camptotheca acuminata is a main source of the anti-cancer drug camptothecin (CPT). In this species, several studies have observed non-glandular trichomes (NGTs) and glandular trichomes (GTs). It has been assumed that GTs contain CPT, yet this has not been proven and no information is available on the accumulation of other secondary metabolites. The objective of this study was to describe the morphology, distribution and structure of C. acuminata trichomes and to investigate the chemical nature of the substances secreted by GTs. Light and fluorescence microscope, scanning electron microscope (SEM) and transmission electron microscope (TEM) were used to determine the morphology, distribution and structure of GTs and NGTs. Thin layer chromatography (TLC) and high-performance liquid chromatography (HPLC) analyses were carried out to confirm the presence of CPT in GTs, and histochemical tests were performed to investigate the presence of other secondary metabolites. C. acuminata possesses two types of GTs (GT1…
cell specific expression of tryptophan decarboxylase and 10 hydroxygeraniol oxidoreductase key genes involved in camptothecin biosynthesis in Camptotheca acuminata decne nyssaceaeBMC Plant Biology, 2010Co-Authors: Alessio Valletta, Livio Trainotti, Anna Rita Santamaria, Gabriella PasquaAbstract:
Camptotheca acuminata is a major natural source of the terpenoid indole alkaloid camptothecin (CPT). At present, little is known about the cellular distribution of the biosynthesis of CPT, which would be useful knowledge for developing new strategies and technologies for improving alkaloid production.
anthocyanic vacuolar inclusions in cell suspension cultures of Camptotheca acuminata decneCaryologia, 2007Co-Authors: Valletta Alessio, Isabella Moro, Nicoletta Rascio, Gabriella PasquaAbstract:
W edemonstrated the presence of anthocyanic vacuolar inclusion (AVI) in anthocyanin-producing cells of Camptotheca acuminata Decne cultured in vitro. During the four cell growth cycles, the number of cells with a col- ourless vacuole decreased. The percentage of cells with AVIs increased during the first and second cell growth cycles and then decreased. This decrease was accompanied by a considerable increase in the percentage of cells with no AVIs, with anthocyanins dissolved in the vacuolar solution. The cytochemical analysis applied to the transmission electron microscopy, revealed the presence of a protein component in the shell of the AVIs.
Craig L Nessler – 2nd expert on this subject based on the ideXlab platform
camptothecin and 10 hydroxycamptothecin from Camptotheca acuminata hairy rootsPlant Cell Reports, 2004Co-Authors: Argelia Lorence, Fabricio Medinabolivar, Craig L NesslerAbstract:
Camptothecin (CPT) is an anticancer and antiviral alkaloid produced by the Chinese tree Camptotheca acuminata (Nyssaceae) and some other species belonging to the families Apocynaceae, Olacaceae, and Rubiaceae. Bark and seeds are currently used as sources for the drug. Several attempts have been made to produce CPT from cell suspensions; however, the low yields obtained limit this approach. Cultures of differentiated cell types may be an alternative source of alkaloid production. Hairy root cultures of C. acuminata were established from tissue transformed with Agrobacterium rhizogenes strains ATCC 15834 and R-1000. Integration of the genes responsible for the hairy-root phenotype (rol genes) into the plant genome was verified by DNA gel blot analysis. The hairy roots produce and secrete CPT as well as the more potent and less toxic natural derivative, 10-hydroxycamptothecin (HCPT), into the medium. Remarkably, the cultures were able to synthesize the alkaloids at levels equal to, and sometimes greater than, the roots in planta, i.e., 1.0 and 0.15 mg/g dry weight for CPT and the HCPT, respectively.
sustained harvest of camptothecin from the leaves of Camptotheca acuminataJournal of Natural Products, 1997Co-Authors: Rebecca M Vincent, Melina Lopezmeyer, Thomas D Mcknight, Craig L NesslerAbstract:
Over a 12-week period, new growth was collected at different intervals from Camptotheca acuminata trees to determine whether a leaf harvest strategy would be an efficient means for the production of the alkaloid camptothecin. Because camptothecin accumulates in young leaves and because the harvesting of young tissue stimulates axillary bud outgrowth, this strategy increased the harvestable amount of camptothecin from trees in a nondestructive manner.
clonal propagation of Camptotheca acuminata through shoot bud culturePlant Cell Tissue and Organ Culture, 1996Co-Authors: Ashok K Jain, Craig L NesslerAbstract:
The chinese tree Camptotheca acuminata produces the anti-cancer and anti-retroviral drug camptothecin. Methods were developed for the clonal propagation of this important medicinal plant through shoot bud culture. Shoot buds were excised from 25 to 30 day old seedlings, presoaked for 48 h in three different liquid media containing either BA (2.22–17.4 μM), kinetin (2.32–18.58 μM), or thidiazuron (0.1–10 μM) and were subsequently cultured on semi-solid medium of the same composition. Multiple shoots only developed from the 6-benzyladenine presoaked explants with the maximum number of shoots initiated from buds presoaked in and grown on B5 medium containing 17.4 μM 6-benzyladenine. Individual shoots were removed from clusters and rooted on B5 supplemented with indole-3-butyric acid (4.9–19.6 μM). The lowest concentration of indole-3-butyric acid (4.9 μM) gave the highest percentage of rooting (82%) and the shortest root initiation period (18 d). Over 90% of the in vitro rooted plantlets survived transfer to soil.
Kexuan Tang – 3rd expert on this subject based on the ideXlab platform
examination of camptothecin and 10 hydroxycamptothecin in Camptotheca acuminata plant and cell culture and the affected yields under several cell culture treatmentsBiocell, 2010Co-Authors: Yan Pi, Kexuan Tang, Yifu Gong, Keji JiangAbstract:
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. Alkaloid accumulation by cells under various treatments (heavy metal ions, UV-B), methyl-jasmonate, absci- sic 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 sali- cylic acid (which showed a 25-fold increase in 10-hydroxycamptothecin concentration). These results are significant in the context of the production of both pharmaceuticals.
molecular cloning and characterization of a novel stem specific gene from Camptotheca acuminataJournal of Biochemistry and Molecular Biology, 2006Co-Authors: Yan Pi, Zhihua Liao, Yourong Chai, Hainian Zeng, Peng Wang, Yifu Gong, Yongzhen Pang, Kexuan TangAbstract:
: In higher plants, P450s participate in the biosynthesis of many important secondary metabolites. Here we reported for the first time the isolation of a new cytochrome P450 cDNA that expressed in a stem-specific manner from Camptotheca acuminata (designated as CaSS), a native medicinal plant species in China, using RACE-PCR. The full-length cDNA of CaSS was 1735 bp long containing a 1530 bp open reading frame (ORF) encoding a polypeptide of 509 amino acids. Bioinformatic analysis revealed that CASS contained a heme-binding domain PFGXGRRXCX and showed homology to other plant cytochrome P450 monooxygenases and hydroxylases. Southern blotting analysis revealed that there was only one copy of the CaSS present in the genome of Camptotheca acuminata. Northern blotting analysis revealed that CaSS expressed, in a tissuespecific manner, highly in stem and lowly in root, leaf and flower. Our study suggests that CaSS is likely to be involved in the phenylpropanoid pathway.