The regulative sequence (2273 bp) of the chalcone synthase gene promoter of biloba was cloned by genomic walking. A 2273-bp promoter 5' upstream translation start site of GbCHS was cloned and designated as GbCHSP. pBI121+CHSP:GUS and pBI121-35S:GUS were constructed and transformed into tobacco by LBA4404. We found that GbCHSP could drive transient expression of GUS in tobacco and differentially expressed in root, stem and leaf tissues of this plant.
Ginkgolides are key pharmaceutical components in Ginkgo biloba leaves. 1-Deoxy-D-xylulose-5-phosphate synthase (GbDXS) and geranylgeranyl pyrophosphate (GbGGPPS) genes are critical genes involved in ginkgolide biosynthesis. In this study, the promoters of GbDXS and GGPPS, with 676 and 570 bp in length, respectively, were cloned by chromosome walking. The cis-elements of GbDXS and GbGGPPS promoters were predicted and analyzed by the plant cis-acting regulatory element (CARE) database.
Cultivar identification is a key step to avoid the formation of homonyms and synonyms of Ginkgo biloba. In this study, a new approach based on combinational utilization of polymorphic bands produced from 6 different random amplified polymorphic DNA (RAPD) primers was developed for identifying 42 Ginkgo cultivars, and a manual cultivar identification diagram that consisted of polymorphic bands produced from different RAPD primers was reported.
Ginkgo biloba (Egb 761) extract, the most prescribed phytomedicine in Europe for the treatment of cerebral insufficiency and vascular diseases, was tested for its possible protective effects against mitomycin C (MMC)- and cyclophosphamide (CP)-induced mutagenicity using the micronucleus test in mouse bone marrow. The extract was co-administered to mice at doses of 50, 100 and 200 mg/kg (po) with 4 mg/kg (ip) MMC or 24 mg/kg (ip) CP.