Адаптація клону моху Pottia intermedia до ртуті

Abstract

To differentiate between the physiologic and genetic adaptations in the clone from an individual gametophyte cell of moss Pottia intermedia, the small explants of leaf plates were regenerated on the Knop-agar medium containing 0.5–1.7 μM HgCl2. The survival percentage was found to be 38.5–1.1%, respectively, elevating with increase of the explant size in plants and recloned from a lower HgCl2 concentration to higher ones. As compared with the mutation rate, the high survival percentage can be regarded as a consequence of metal-induced permanent adaptive epigenetic changes. The area of unilaminate leaflets of mosses recloned from the metal-containing medium on the control one is enlarged by 2.4–3.2 times, while the leaf cell area remains constant, indicating the increase of the cell division rate. The intensity of the luminescence of nuclear DNA-acridine orange in plants adapted to mercury exhibited the pronounced tendency to increase, while a decrease of the DNA-AO luminescence of nuclei after the treatment with DNase 1 was more weakly expressed in plants survived on mercury than in control ones. The results suggest that the genetic adaptation in the moss clone can be caused by the amplification of certain DNA sites related to the mitotic activity.