Effects of caffeine pre-and posttreatment on the frequencies of sister chromatid exchanges and exchange-aberrations induced by quinacrine mustard and UV-light in Vicia faba L.

Abstract

Lateral roots of Vicia faba L. were grown for one cell cycle in presence of 5'-bromodeoxyuridme (BrdU), followed by another cell cycle in presence of thymidine. Between these treatments root tips were exposed to either quinacrine mustard or to UV-light, both known to induce structural chromosome aberrations of the exchange type and sister chromatid exchanges (SCE). An additional treatment with caffeine during the first cell cycle (pretreatment) led to a reduced number of exchange aberrations, whereas caffeine given during the second cell cycle (posttreatment) increased the frequency of exchange aberrations. SCE frequencies were not affected by caffeine. The effects of caffeine pre- or posttreatment on chromatid exchange aberrations and the relationship between exchange aberrations and sister chromatid exchanges are discussed.