Variability of DNA markers in Arabidopsis thaliana cultured cells under standard growing conditions and under the influence of stressors

Resumo

We investigated the genetic heterogeneity of two A. thaliana callus lines, which had been cultured in vitro, respectively, for 6 months and 8 years under standard conditions and after exposure to abiotic stressors (high temperature, anoxia, and toxic copper ions). Under standard culture conditions, the level of genetic diversity identified by AFLP was 1.2% for the six-month-old callus and 5% for the older cultivated one. In stress conditions, we observed a decrease in the level of genetic diversity of cells in both of the lines analyzed. There was no conclusive evidence of the induction of changes in the DNA nucleotide sequence under the influence of unfavorable conditions. The effect of stressors was manifested primarily at the level of cell populations and was expressed as a selection of cells with certain genotypes.