Nicotiana sylvestris L. mutants resistant to isopropyl N-phenyl carbamate possess microtubule organizing centers of heightened stability

N. sylvestris mutants resistant to isopropyl N-phenyl carbamate (IPC), a herbicide belonging to the phenyl carbamate series, are obtained by means of in vitro selection using gamma radiation. A concentration of 30 μM IPC was found to be the maximum concentration at which mutants of the N. sylvestris line capable of regeneration and rooting under conditions of selection pressure could be selected. IPC resistance in the mutants obtained was confirmed by a number of tests, in particular, tests that measure the capacity of leaf explants of the mutant lines to regenerate plants and the ability of their callus cells to survive in media with a selective IPC concentration, as well as by means of genetic, morphometric, cytological, and immunofluorescent analyses. The results of these studies attest to increased resistance of the mutant plants to this antimitotic substance by comparison with a control. It is shown that resistance to IPC is based on the heightened resistance of the microtubule organizing centers of the cells of these lines. It is established that the acquired resistance trait inherited in the F₁ and F₂ generations of the mutants is a dominant nuclear trait.