Low temperature, gibberellin and acid lipase activity in removal of apple seed dormancy

Abstract

Abstract The activity of acid lipase and the level of gibberellin A 4 (GA 4 ) were determined in apple embryos excised from seeds after different time periods of stratification and subsequently cultured in darkness at 4°C or at 25°C. Enzyme activity and GA 4 content were higher at 4°C. Exogenous gibberellin stimulated lipase activity, while AMO‐1618, an inhibitor of gibberellin biosynthesis, inhibited, to the same degree, both the enzyme activity and the GA 4 accumulation. The involvement of GA 4 and lipolytic enzymes in cold‐mediated removal of embryonal dormancy has been discussed and compared with the role of these two factors in light‐stimulated germination of dormant apple embryos, described earlier (Smoleńska and Lewak 1974).