The sensitivity of Crepis capillaris transgenic roots to mutagenic factors

Rapid progress has recently been made in biotechnology, especially in the development of transformation techniques including transgenic roots - hairy roots. Transgenic root cultures are used not only as a source of secondary metabolites, but have also proven to be a very good material for cytogenetic analysis of cytotoxic and mutagenic effect of environmental factors on plant cells. In the present study, the sensitivity of transgenic roots of Crepis capillaris has been analysed. The agents used for treatment were X-rays, maleic hydrazid acid - mutagen effective in the S phase, and oryzaline - herbicide that causes depolimerization of mitotic spindle microtubules. Crepis capillaris is a very good model plant for those studies because it has three pairs of relatively big and morphologically differentiated chromosomes. The transformed Crepis roots grow quickly and are easy to culture in vitro. This makes it very convenient for the analysis of the influence of mutagenic and stress factors on plant cell. The effect of mutagenic treatments was estimated using two mutagenic tests namely micronucleus test and anaphase - telophase test. Additionally, fluorescence in situ hybridization with 45S rDNA was applied in order to analyse the involvement of NOR chromosomes in the formation of micronuclei, fragments and other types of chromosomal aberrations. Sister chromatid exchanges (SCE) were analysed to test the structural chromosome changes. The analysis of the changes in cells of Crepis capillaris after oryzaline treatment encompassed also the observation of microtubules of cytoskeleton and of mitotic spindle using the immunocytochemical approach. The results show different sensitivity of cells in 'hairy roots' and primary roots of Crepis capillaris to mutagenic factors. (author)