Repetitive somatic embryogenesis induced cytological and proteomic changes in propagated embryogenic lines of Pseudotsuga menziesii [Mirb.]

Objectives: to characterize and to better understand changes at the cellular and molecular levels, in embryogenic lines in Douglas-fir obtained after repetitive somatic embryogenesis, that could explain improvement of their embryogenic potential : to primary lines, secondary ones showed an increase of their embryogenic potential; then tertiary lines showed again an improved embryogenic potential compared to second lines. Interestingly, the proteomic analysis further revealed different sets of significant proteins suggesting that each cycle of repetitive somatic embryogenesis is promoting substantial genome-wide rearrangement of the gene expression pattern.