Radioactive Chernobyl Environment Has Produced High-Oil Flax Seeds That Show Proteome Alterations Related to Carbon Metabolism during Seed Development

Starting in 2007, we have grown soybean
(Glycine max [L.] Merr. variety Soniachna) and flax
(Linum usitatissimum, L. variety Kyivskyi) in the
radio-contaminated Chernobyl area and
analyzed the seed proteomes. In the second-generation flax seeds,
we detected a 12% increase in oil content. To characterize the bases
for this increase, seed development has been studied. Flax seeds were
harvested in biological triplicate at 2, 4, and 6 weeks after flowering
and at maturity from plants grown in nonradioactive and radio-contaminated
plots in the Chernobyl area for two generations. Quantitative proteomic
analyses based on 2-D gel electrophoresis (2-DE) allowed us to establish
developmental profiles for 199 2-DE spots in both plots, out of which
79 were reliably identified by tandem mass spectrometry. The data
suggest a statistically significant increased abundance of proteins
associated with pyruvate biosynthesis via cytoplasmic glycolysis, l-malate decarboxylation, isocitrate dehydrogenation, and ethanol
oxidation to acetaldehyde in early stages of seed development. This
was followed by statistically significant increased abundance of ketoacyl-[acylcarrier
protein] synthase I related to condensation of malonyl-ACP with elongating
fatty acid chains. On the basis of these and previous data, we propose
a preliminary model for plant adaptation to growth in a radio-contaminated
environment. One aspect of the model suggests that changes in carbon
assimilation and fatty acid biosynthesis are an integral part of plant
adaptation.