Mitotic blocking, micronucleation, and chromosome doubling by oryzalin, amiprophos-methyl, and colchicine in potato

Abstract

The data on mitotic blocking, induction of micronuclei, and chromosome doubling after treatments of transformed potato suspension cells with three different anti-microtubule agents oryzalin, amiprophos-methyl (APM) and colchicine are reported. The fast growing cell suspension line 413 with high mitotic activity is used, which contains various T-DNA introduced genetic markers (kanamycin resistance, β-glucuronidase activity, hairy root phenotype, hormone autotrophy, opine production). When compared to colchicine (0.5–5.0 mM), oryzalin and APM (15–32 μM) arrested the cells in metaphase more efficiently, induced micronucleated cells at higher frequencies and yielded a greater number of micronuclei. Flow cytometric determination of nuclear DNA content in interphase cells and the analysis of chromosome numbers in mitotic cells after removal of the chemicals and subculture showed that oryzalin is the most efficient chromosome doubling agent followed by APM and colchicine in that order. The anti-microtubule properties of the spindle toxins and interrelationship of various cellular events are discussed in relation to the mechanisms and factors involved in mitotic blocking, micronucleation and chromosome doubling.