Mitotic blocking agents for suspension cultures of maize 'Black Mexican Sweet' cell lines

Abstract

Good metaphase arrest (25% mitotic index) in maize (Zea mays L.) 'Black Mexican Sweet' suspension cultures can be obtained with colchicine treatment alone, but only if very high concentrations (0.5%; 12.5 mM) are used. This colchicine concentration is 5- to 10-fold greater than that required for optimum mitotic arrest in cell cultures of other plant species. In contrast, we report that the herbicide amiprophos methyl (APM) is a much more efficient metaphase inhibitor for 'Black Mexican Sweet' suspension cultures than colchicine. Low concentrations (50 μm) of APM applied for 21–28 h produce a similar 25% mitotic index, and the growth-inhibiting effects of this treatment are undetectable 24 h after the removal of APM from the culture medium, APM, therefore, may be a useful agent for mitotic arrest in experiments which require survival of the treated cells. Another antitubulin herbicide, trifuralin, also was tested for ability to promote metaphase arrest in 'Black Mexican Sweet' cultures, but it proved to be ineffective.Key words: mitotic arrest, colchicine, phosphoric amide herbicide.