Some factors affecting sister-chromatid differentiation (SCD) and sister-chromatid exchange (SCE) in Hordeum vulgare.

A study of some factors affecting sister-chromatid differentiation (SCD) and sister-chromatid exchanges (SCE) in Hordeum vulgare is reported. After we studied the influence of 5-fluorodeoxyuridine (FdU) and growth temperature on SCE in barley cells, and the effect of FdU, growth temperature, the growth time of plant cells in 5-bromo-2-deoxyuridine (BrdU) solution on SCD, we found an experimental condition under which the frequency of SCE is lower, but the percentage of SCD is higher. Our data show that ascorbic acid, mitomycin C, adriamycin, and maleic hydrazide induce SCEs in cells of Hordeum vulgare by means of free radicals. This can be shown from the two observations: (1) sulfhydryl compounds such as cysteine and glutathione can completely or partially inhibit the SCEs induced by ascorbic acid, mitomycin C, adriamycin and maleic hydrazide; (2) the amounts of free radicals in root tips correlate with the frequencies of SCE in root tip cells.