Inhibition of RNA synthesis in Chlorella pyrenoidosa and Bacillus megaterium by the pine-blight toxin, dothistromin.

Dosthistromin, an anthraquinone derivative produced by the pine-blight fungus, Dothistroma pini, inhibits the growth of Chlorella pyrenoidosa and Bacillus megaterium. At growth inhibitory concentrations, dothistromin strongly inhibits incorporation of [3H]uridine into RNA of both species. With B. megaterium, marked inhibition of [3H]uridine incorporation is apparent within 5 min of addition of dothistromin, but only a slight inhibition of [3H]thymidine incorporation into the DNA-containing fraction or of [14C]leucine incorporation into protein is detectable after 10 min.