Kee-Yoeup Paek

Combined effects of phytohormone, indole-3-butyric acid, and methyl jasmonate on root growth and ginsenoside production in adventitious root cultures of Panax ginseng C.A. Meyer

Indole-3-butyric acid at 25xa0μM with methyl jasmonate (MJ) at 100xa0μM in Panax ginseng synergistically stimulated both root growth and ginsenoside accumulation compared with 100xa0μM MJ alone. Productivity of ginsenoside was 10xa0mgxa0l−1xa0d−1 compared to 7.3xa0mgxa0l−1xa0d−1 with MJ elicitation alone.

The Effectiveness of Selection for Salinity Tolerance Using In vitro Shoot Cultures

Shoot cultures of sugarbeet (Beta vulgaris `Prima Hill), tobacco (Nicotiana tabacum `Wisconsin 38), Chinese cabbage (Brassica campestris ssp. pekinensis `Kimjung), and canola (Brassica napus `Westar) were grown on media with and without additional salt. After varying times in culture (6-24 subcultures) with salt, growth tests were used to assess salt tolerance. There was no evidence for any increase in tolerance in the selected cultures, and, in all species except sugarbeet, selected cultures showed less vigor than controls. The morphogenic reponse of leaf explants from sugarbeet shoots selected on 140 mM Na2SO4 was much greater than that from the control culture. Tobacco and sugarbeet shoot cultures were more tolerant than either Brassica species and had a higher water content. In both Chinese cabbage and sugarbeet, the concentration of reducing sugars decreased on salt, while sucrose remained at a lower, but relatively constant, level. When grown on salt, Chinese cabbage produced proline, and sugarbeet produced quaternary ammonium compounds. In Chinese cabbage, Na2SO4 was more inhibitory than NaCl.

Auxin Affects on Production of Adventitious Roots and Secondary Metabolites in Echinacea angustifolia

The production of adventitious roots derived from root explant of Echinacea angustifolia and its secondary metabolite content were assessed in different types and levels of auxin. The induction of adventitious roots from root explant cultured in Murashige and Skoog solid medium supplemented with 1.0 mg/L indole -3-butyric acid (IBA) attained highest as 20.87 mg fresh weight and 3.07 mg dry weight per culture but root suspension culture at the same concentration of IBA enhanced biomass production as 3.07 g fresh weight and 0.38 g per culture after 4 weeks in culture. 3.0 mg/L -naphthalene acetic acid (NAA) treatment had similar effect on root biomass production as 3.07 g fresh weight and 0.38 g per culture with liquid suspension culture, whereas adventitious roots exposed to over 3.0-5.0 mg/L IBA or 5.0 mg/L NAA were less responsive by reducing the number of adventitious roots and/or changing root morphology such as short and thick. The content of secondary metabolites such as phenolic, flavonoids and total caffeic acid in adventitious roots cultured on MS medium supplemented with 1.0 mg/L IBA were attained highest as 27.20, 9.60. 10.67 mg/g dry weight, respectively. Overall, the best production of root biomass and secondary metabolites were given by 1.0 mg/L IBA.

Micropropagation of Raphanus sativus L. var. longipinnatus (Japanese radish) cv. Gungjung

Shoot cultures were established from seedling shoot tips of Raphanus sativus var. longipinnatus Bailey cv. Gungjung, (Japanese radish) cultured on a Murashige-Skoog medium supplemented with ca. 4.5–135 μM kinetin or N6-benzyladenine. The latter cytokinin supported overall better growth, and 22.2 μM was adopted for maintenance of established cultures. The nitrate: ammonium levels in the medium proved optimal for growth and shoot proliferation and both these parameters were significantly increased by addition of adenine sulfate or sodium phosphate. Rooting of excised shoots was achieved on auxin containing medium. Indole-3-butyric acid (ca. 5 or 10 μM) also enhanced shoot growth. Plants were easily established in soil, appeared morphologically normal, and flowered.

Sodium Sulfate Tolerance in Beta vulgaris (Sugar Beet) Callus Cultures

Beta vulgaris L. cv Prima Hill (sugar beet) callus, was selected for tolerance to Na2SO4 and maintained on this salt. The effect of 0, 70, 140, and 210 mM Na2SO4 on the concentrations of ions, reducing sugars, sucrose, quaternary ammonium compounds (QACs), and proline in unselected and selected callus was assessed. Both types responded similarly. Sodium accumulated in proportion to its initial concentration in the medium, while calculated molar concentrations of proline, reducing sugars, and sucrose increased slightly. There was a fourfold increase in the concentration of QACs. Tolerance, measured by survival and growth, was lost within one subculture in selected callus maintained without Na2SO4, although the high FW:DW ratio, characteristic of tolerance, was retained in the absence or presence of Na2SO4. Evidence suggests physiological adaptation to Na2SO4 occurred during selection.

Plant Cell and Organ Culture as an Alternative for the Production of Anticancer Compounds

Plants are the reservoirs of various valuable secondary metabolites like camptothecin, podophyllotoxin, and ginseng saponins which are used as anticancer agents. Plant cell and organ cultures are competent to synthesize and accumulate many of these compounds and can be used as a source for extraction of such compounds. Different strategies have been applied for overaccumulation of secondary metabolites in plant cell cultures which include screening and selection of high yielding cell lines, optimization of nutrient media, and elicitation. In the present chapter, some of the anticancer compounds derived from plant cell and organ cultures are described, and various strategies for improving the accumulation of useful secondary metabolites in cell and organ cultures and methods for the large-scale production using bioreactors are highlighted.