Gibberellic acid and Cold Effect on Protein Variation in Ferula gummosa Boiss. seeds

Seeds of Galbanum (Ferula gummosa Boiss.) are characterized by a very low rate of germination in the laboratory condition due to the difficulties to find efficient breaking factors of the complex dormancy of these seeds. To some extent gibberellic acid (GA3) and cold temperatures can contribute to the removal of dormancy. In this study the effects of gibberellic acid pretreatments (0, 500, 1000, 1500 mM) and different temperatures (-20°C, 4°C, 8°C) given during seeds soaking step were measured on changes in electrophoretic patterns of proteins of different treated samples. The seeds pre-treated with 500 mM GA3 or 4°C germinated with a germination rate of 22% and 8% respectively. Lots of seeds, treated by other temperature conditions, which were not germinated, have an electrophoretic profile of proteins mainly characterized by the absence of three polypeptide bands. These bands are present in the protein fraction of seeds treated with GA3 and 4 °C even if the seeds did not have germinated. A 23kDa polypeptide not well present in GA3 or 4°C treated germinated and non-germinated seeds, was well presented in recalcitrant seeds. The comparison with the standard profile of alpha- amylase shows that two of these polypeptide bands correspond to this enzyme. The heterogeneity of F.gummosa response to dormancy breaking treatment was accompanied by changes in the levels of some peptides of interest in order to study further in the future. These results also highlight the role of GA3 and coldness on the synthesis of alpha-amylase involved in the metabolic activation for seeds germination of Ferula gummosa