biologia plantarum

Biologia plantarum 33:216, 1991 | DOI: 10.1007/BF02897886

Analysis of globulin maturation in developing sunflower seeds

E. Ferjani¹, G. Ledoigt¹

¹ Laboratoire de Phytomorphogenèse, Biologie et Physiologie végétales, Université Blaise-Pascal (Clermont II), Clermont-Ferrand, France

The synthesis of major storage globulin polypeptides has been examined in developing seeds of sunflower(Helianthus annuus L.). Analyses of total proteins and purified globulins, also called helianthinin, by gel electrophoresis and immunoelectrophoresis have shown that a burst of protein synthesis and accumulation occurs around 10 d after flowering. There is no mature globulin before that time and only small amounts of precursor forms can be detected. Thus, 10-12 d after flowering appears to be a transition period during which genetic information for the globulin becomes actively expressed. Immunoelectrophoresis has confirmed that globulin is the main storage protein, at seed maturation, accounting up to 70 % of total proteins per kernel. Pulse chase experiments have shown that synthesis initially involves the formation of high molecular mass precursors and that storage proteins are post-translationally processed. Intermediary products, with molecular mass higher than early translational products, can be detected, together with mature globulin polypeptides.

Received: March 2, 1990; Accepted: August 20, 1990; Published: May 1, 1991  Show citation