Histological and 2-D protein patterns comparisons between a wild type and a somatic embryogenic mutant of Asparagus officinalis L.

We study the induction of somatic embryogenesis using an original Asparagus model: a mutant type which an important somatic embryogenesis and its non- embryogenic wild type used as control. We describe the histological events and the modifications of protein patterns occurring during the initiation o f somatic embryogenesis in cultures of apices. Using the mutant type apices , pro-embryogenic masses and embryogenic cells are observed at the peripher y of the callus after transfer on hormone-free medium while in the same cul ture conditions, the wild type calli never show embryogenic structure. Anal ysis of the tissular proteins during the culture leads us to classify 116 p roteins into 20 groups potentially related to somatic embryogenesis. Two of these groups are particularly interesting as they correspond to polypeptid es that are only related to one of the two types: six polypeptides (group 1 ) are specific to the mutant type apices and could be related to the compet ence of the mutant tissues with respect to somatic embryogenesis. Eleven pr oteins (group 7) are detected specifically in the wild type tissues and the ir presence could be related to an inhibition of the somatic embryogenesis ability. (C) 1999 Elsevier Science Ireland Ltd. All rights reserved.