Effects of caffeine on the frequencies of chromosomal aberrations and sister chromatid exchanges induced by chemical mutagens in root tips of Vicia faba

Abstract

Lateral roots of Vicia faba were grown for one cell cycle in the presence of 5‐bromodeoxyuridine (BrdUrd) and then for another in the presence of thymidine. Between BrdUrd and thymidine treatments the roots were exposed for 1 or 2 hours to one of the following substances: MMS, EMS, MNNG, quinacrine mustard, mitomycin C, thiotepa, bleomycin or maleic hydrazide. All these agents produced chromosomal aberrations and, with the exception of bleomycin, strongly increased the frequency of sister chromatid exchanges (SCEs). The addition of caffeine to the thymidine solution resulted in a strong increase in the frequencies of chromosomal aberrations induced by these substances, but had no significant effect on the frequencies of induced SCEs. This suggests that chromosomal aberrations and SCEs are produced by mechanisms that are at least partly different. © 1978 Mendelian Society of Lund