Production of insect juvenile hormone III and its precursors in cell suspension cultures of the sedge, Cyperus iria L.

 Juvenile hormones (JHs) are sesquiterpenoids that regulate metamorphosis and reproduction in most insect species. There has been one report of an insect JH in plants: JH III, methyl-10R,11-epoxy-3,7,11-trimethyl 2E, 6E-dodecadienoate, has been identified in two sedge species, Cyperus iria L. and C. aromaticus (Ridley) Mattf and Kük. This is the first report of callus and cell suspension cultures derived from C. iria. Farnesol and methyl farnesoate, two biosynthetic intermediates of JH III in insects, as well as JH III have been identified in suspension culture cell extracts by gas chromatography-mass spectroscopy. These cultures thus provide a useful in vitro model to investigate the biosynthesis of JH III in the sedge, C. iria. Received: 30 October 1998 / Revision received: 11 February 1999 / Accepted: 3 March 1999     

In vitro Induction of primary antibody responses to particulate and soluble protein antigens in T cell—replaced murine spleen cell cultures

Specific antibody responses could be induced in serumfree condition.Specific anti-SRBC or anti-SRBC ghost antibody were induced from anti-Thy treated (T-depleted) murine spleen cells in serum-free culture in the presence of Con A conditioned medium.This induction system may facilitate the study of lymphokine functions on antigen triggered B cells. In T cell-replaced cultures,the antibody responses of B cells could be successfully induced when soluble SRBC membrane proteins were used as antigens.It thus indicates that antigen together with lymphokines are sufficient to drive B cells to become antibody secreting cells in the absence of T cells.The T cell-replaced system provides a more stable way for in vitro immunization and may be applied to monoclonal antibody production when in vivo immunization is difficult to be carried out.     

High-frequency plant regeneration via somatic embryogenesis and organogenesis and in vitro flowering of regenerated plantlets in Panax ginseng

 The morphogenesis ability of light yellowish globular callus derived from cotyledons of mature zygotic embryos of Panax ginseng was investigated. The optimal media for somatic embryogenesis and shoot organogenesis were MS medium containing 0.5 mg l^–1 2,4-dichlorophenoxyacetic acid, 0.1 mg l^–1 6-benzyladenine (BA), and 500 mg l^–1 lactoalbumin hydrolysate, and SH medium supplemented with 0.5 mg l^–1 α-naphthaleneacetic acid, 0.1 mg l^–1 BA, and 500 mg l^–1casein hydrolysate. The influences of glucose, mannose, fructose, and sorbose in the media on somatic embryogenesis and shoot organogenesis were revealed as differences in the numbers of somatic embryos and adventitious shoots per gram of morphogenic callus. The best regeneration of somatic embryos was obtained on medium containing glucose, with a mean of 8.7 somatic embryos per gram of callus. The best regeneration of shoots was observed on medium containing fructose, with an average of 12.2 adventitious shoots per gram of callus. Of the somatic embryos 95% were converted into regenerated plantlets, and 100% of adventitious shoots rooted to form regenerated plantlets. Regenerated plants were successfully established in soil. Flowering was observed in 5.7% of the regenerated plants derived from shoot organogenesis and in 1.4% of the regenerated plants derived from somatic embryogenesis. Received: 1 December 1998 / Revision received: 13 September 1999 / Accepted: 20 September 1999     

Transient expression of antibodies in suspension plant cell suspension cultures is enhanced when co‐transformed with the tomato bushy stunt virus p19 viral suppressor of gene silencing

Two distinct transient expression approaches were compared with assess the impact of the viral suppressor p19 on a recombinant protein production performed in Nicotiana benthamiana suspension culture. A parental N. benthamiana cell line was transiently transformed with either an Agrobacterium containing a gene construct for a murine IgG1 (R514) or concurrently with two Agrobacteria containing R514 or p19. In addition, a stably transformed N. benthamiana cell line that constitutively expresses p19 was transformed with R514‐containing Agrobacterium. The parental N. benthamiana cell line that had been co‐cultivated with both p19 and R514 achieved the highest yield of IgG1 (1.06 mg IgG1/kg FW; 0.024% TSP) compared with that obtained without p19 (0.61 mg IgG1/kg FW; 0.014% TSP). The N. benthamiana cell line that had been stably transformed with p19 only reached 0.25 mg IgG1/kg FW (0.009% TSP) when co‐cultured with R514‐containing Agrobacterium. Dual agroinfiltration of N. benthamiana leaves with p19 and R514 was also performed to assess for Agrobacteria efficiencies and 147.7 mg IgG1/kg FW were obtained. Therefore, our results demonstrate that transient co‐transformation of plant cell suspension culture with two transformation vectors is feasible and that the use of the viral suppressor of silencing p19 significantly raises the production of the protein of interest. © 2010 American Institute of Chemical Engineers Biotechnol. Prog., 2010