Agrobacterium-mediated genetic transformation of secondary somatic embryos in alfalfa / 生物工程学报

We describe a genetic transformation method of secondary somatic embryogenesis in alfalfa through cotyledon-stage somatic embryos of alfalfa infected by Agrobacterium strain GV3101. The Agrobacterium strain GV3101 contained binary vector pCAMBIA2301 that had gus gene as reporter and npt II gene as selectable marker. The infected primary embryos were induced through series of medium under 75 mg/L kanamycin selection. We obtained the transgenic alfalfa plants. Then, GUS expression in different tissue of transgenic alfalfa was tested by GUS histochemical analysis. Further, the stable integration and transformation efficiency were tested by polymerase chain reaction and Southern blotting hybridization. The result showed that GUS expression was different in different organs of transgenic alfalfa; the copy number of integrated npt II gene was from 1 to 4; the transformation efficiency via primary somatic embryogenesis was 65.82%.

End point determination by HPLC chromatographic fingerprint in processing prepared Rehmannia / 中国中药杂志

To establish HPLC chromatographic fingerprints to control the quality of Chinese herbal medicine. In this study, fingerprints were established based on HPLC-DAD chromatographs. And with these fingerprints, content variations of three important active components catalpol, 5-hydroxymethylfurfural and acteoside in Rehmannia rhizome were analyzed during processing, as well as changes of the fingerprints. Fingerprints comparing with the standard prepared Rehmannia fingerprints which came from the mean of prepared ones randomly chosen for standard was done to seek optimal processing time. The results indicated that catalpol decreased quickly as braising prolonged and almost vanished in the end. While the active component of 5-HMF increased linearly throughout the process of braising. And the content of acteoside did not show obvious change. Similarity to standard prepared Rehmannia reached summit after braising for 26 hours. So 26 hours could be considered to be the optimum time for braising prepared Rehmannia. Chromatographic fingerprint is convenient for revealing changes of constituents and for accurately controlling quality during processing prepared Rahmannia.