STRAIN OF ROSA-DAMASCENA CULTURED-CELLS RESISTANT TO ULTRAVIOLET-LIGHT

A strain of cultured cells of R. damascena Mill. cv. Gloire de Guillan which showed unusual resistance to damage by short wave (254 nm) UV radiation was isolated. The resistant cells were 2.2-2.8 times larger and had about twice the amount of DNA and more chromosomes than the parental, sensitive cells. The resistant cells also produced larger quantities of polyphenolic compounds, principally flavonoids, during the later phases of culture growth. At 10 days, resistant cells had 4 times more nonflavonoid polyphenolics and 14 times more flavonoids than parental cells. The resistance, which was also observed only in the later phases of culture growth, was best correlated with the production of polyphenolics, which apparently shielded UV sensitive target molecules from damage.