Three major somatic embryogenesis related proteins in Cichorium identifiedas PR proteins

In Cichorium hybrid clone '474' (C, intybus L., var. sativum x C, endivia L ., var. latifolia), the direct somatic embryogenesis process in leaf tissue s is accompanied by an overall increase in the amount of proteins secreted into the culture medium, Amongst these, three major protein bands of 38 kDa , 32 kDa and 25 kDa were found in the conditioned media. These extracellula r protein bands accumulated in the medium of the embryogenic Cichorium hybr id up to 8-fold compared with those in the medium of a nonembryogenic varie ty, 32 and 25 kDa proteins were purified from the medium and their identiti es were determined as already described for 38 kDa beta-1,3-glucanases, To investigate their possible function in somatic embryogenesis, peptide seque nces, serological relationships or biochemical properties revealed that the re were at least two acidic chitinases of 32 kDa and one glycosylated osmot in-like protein of 25 kDa in the embryogenic culture medium. Comparing the amounts of the 38 kDa glucanases, the 32 kDa chitinases, and the 25 kDa osm otin-like protein present in the conditioned media of the embryogenic '474' hybrid and of a non-embryogenic variety, a 2-8-fold higher accumulation of these proteins was observed in the embryogenic hybrid culture medium. This may suggest that part of the accumulation of these three pathogenesis-rela ted (PR) proteins could be correlated with the somatic embryogenesis proces s, Their possible involvement in this developmental process is discussed.