Modification of UV-B radiation effect on Crepis capillaris by antioxidant and environmental conditions

Stability of cell division and genetic structures has special significance for plant development and productivity. On the basis of literature data about the very low photolyase activity in roots, the action of UV-B radiation and its putative modifying factors were studied on the root meristematic cells of model plant Crepis capillaris. It is really a very sensitive system for UV-B radiation. Action of UV-B was investigated in a wide range of doses (0; 0.75;1.00; 1.13; 1.50; 2.00; 2.50; 3.00 kJ m^-2. The dose of 0.75 kJ m^-2 already decreased the cell division and up to 1 kJ m^-2 UV-B dose induced the chromosome aberrations (CAs). The supplementary B chromosome did not show any effect on CA induction, but plants with B chromosome had a more stable mitotic activity of cells. The strongest protective effect on CA induction was revealed by salicylic acid (10-4 M). Photoreactivation also showed certain decrease of the CA level, and the lowest effect was of ascorbic acid.