Effect of hydrogen peroxide on synthesis of proteins during somatic embryogenesis in Lycium barbarum

Direct exposure of calluses of Lycium barbarum L. to an auxin-free medium can induce somatic embryogenesis. The effect of hydrogen peroxide on synthesis of proteins during somatic embryogenesis in Lycium barbarum L. was studied. One-dimensional gel electrophoresis showed that new protein was synthesized by embryogenic callus II (in MS+200 μmol 1-1 H2O2 medium). Therefore, we suggested that there was a synthesis of H2O2-induced protein during somatic embryogenesis of Lycium barbarum L. Cycloheximide and actinomycin D prevented the synthesis of the new protein (H2O2-induced) effectively. The results of two-dimensional gel electrophoresis showed that the differences in the protein patterns between embryogenic callus occurred at 35∼55 kDa with a pI-level of about 5∼6. Changes at the transcriptional level in embryogenic callus I and II were analyzed by comparing in vitro translation patterns. The results showed that several new in vitro-translated proteins were found in embryogenic callus treated with hydrogen peroxide. It suggests that the exogenous added H2O2 induced genes expression at the mRNA level during somatic embryogenesis of Lycium barbarum L.