The explosion in one of the four reactors of the Chernobyl Nuclear Power Plant (CNPP, Chernobyl) caused the worst nuclear environmental disaster ever seen. Currently, 23 years after the accident, the soil in the close vicinity of CNPP is still significantly contaminated with long-living radioisotopes, such as (137)Cs. Despite this contamination, the plants growing in Chernobyl area were able to adapt to the radioactivity, and survive. The aim of this study was to investigate plant adaptation mechanisms toward permanently increased level of radiation using a quantitative high-throughput proteomics approach. Soybeans of a local variety (Soniachna) were sown in contaminated and control fields in the Chernobyl region. Mature seeds were harvested and the extracted proteins were subjected to two-dimensional gel electrophoresis (2-DE). In total, 9.2% of 698 quantified protein spots on 2-D gel were found to be differentially expressed with a p-value

Embryogenic cell lines initiated from immature zygotic embryos of Pinus nigra Arn. ssp. Austriaca were characterized in terms of macromorphological traits (colour, bipolar structures formation, germination ability) and their embryogenic potential was defined as high, medium or null. Quantification of global genomic DNA methylation revealed the existence of specific DNA methylation levels for the determinated embryogenic potentials. The line considered as effectively embryogenic, i.e., with the ability of develop the whole embryogenic program and producing plants, showed the lowest methylation levels. There was also proved the existence of an inverse relationship between total contents of free PAs and embryogenic potential, being the highest contents of free putrescine and spermidine in the non-embryogenic line and the lowest in the effectively embryogenic one. Relationships among DNA methylation levels, profiles of free individual polyamine contents and embryogenic potentials based on the ability to produce well-formed somatic embryos with effective plant conversion are discussed.