WAVELENGTH DEPENDENCE OF ULTRAVIOLET RADIATION-INDUCED MORTALITY AND K+ EFFLUX IN CULTURED CELLS OF Rosa damascena

Abstract— The sensitivity of the colony-forming ability of rose-cell cultures ( Rosa damascena L. cv Gloire de Guilan) to ultraviolet radiation has been measured for wavelengths from 240-334 nm. These cultures are much less sensitive than bacteria and animal cells in the region from 240-310 nm, an observation attributed to the presence in rose cells of ultraviolet-radiation-absorbing compounds. The effect of the same wavelengths on K+ efflux was also measured and compared to the spectrum for lethality. K+ efflux or damage leading to K+ efflux might contribute to lethality at wavelengths longer than 290 nm but not at shorter wavelengths.