A suspension cultured cell line was established from the cultivar of Rosa hybrida 'Charleston' as a study model to understand the response of the anthocyanin biosynthesis pathway to environmental cues. The major identified anthocyanin in cell cultures was cyanidin 3-glucoside (chrysanthemin). The anthocyanin yield was enhanced by culturing cells in the EM medium with added sucrose at high concentration under additional UV-B radiation to white light. Three cDNA fragments were cloned with degenerate primers by RT-PCR and the obtained sequences shared high homology with putative key enzymes (DFR, ANS, and UF3GT) of other species. The expression levels of these three genes were promoted under optimum conditions for anthocyanin accumulation. These results suggest that expression levels of these genes were closely correlated with a temporal buildup of anthocyanins in response to environmental factors.Key words: Anthocyanin, chrysanthemin, cyanin, Rosa hybrida, suspension cell culture.Plant Biotechnology 23, 379-385 (2006)
Original PaperThis article can be found at http://www.jspcmb.jp/ pelargonidin, cyanidin and peonidin type anthocyanins (Biolley et al. 1994). Recently, tissue culturing has become an important biotechnological technique to produce various secondary metabolites including anthocyanins on a mass scale for industrial and academic interest (Hirner et al. 2001;Gantet and Memelink 2002). Despite the fact that some plant species have been shown to produce anthocyanins in cell cultures, little information of the cell culture techniques that are capable of producing in vitro anthocyanins has been reported in rose.The biosynthesis of anthocyanins in plant cell culture is stimulated by not only genetic factors but also environmental factors such as light, temperature, growth regulators and nutrition (Sato et al. 1996;Zhang et al. 1997;Zhang et al. 2002). The identity of the environmental stimuli that lead to the accumulation of anthocyanins in rose is of considerable interest. To date, Sato et al. (1996) has examined the intensity of white light that induces anthocyanin production in strawberry cell culture lines; however, no information was obtained about the effect of light quality on the production of anthocyanins in cultural cells. Therefore, the originality of this research is to investigate anthocyanin biosynthesis in cultural cells exposed to UV-B (290-320 nm) radiation.In this study, we used Rosa hybrida cultivar 'Charleston', a climbing type, originated in Australia. The open flowers of 'Charleston' undergo a striking color change from yellow to red over 10-12 days under natural daylight. We established a suspension cultured cell line from this cultivar of rose. Anthocyanin content was quantified by HPLC to determine the most efficient conditions, such as light including UV-B radiation and media, for continuous production of the pigments in the rose cell suspension. The expression levels of three genes encoding putative key enzymes (DFR, ANS, and UF3GT) for anthocyanin biosynthesis were ana...