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

Abstract

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 of somatic embryogenesis in cultures of apices. Using the mutant type apices, pro-embryogenic masses and embryogenic cells are observed at the periphery of the callus after transfer on hormone-free medium while in the same culture conditions, the wild type calli never show embryogenic structure. Analysis of the tissular proteins during the culture leads us to classify 116 proteins into 20 groups potentially related to somatic embryogenesis. Two of these groups are particularly interesting as they correspond to polypeptides 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 competence of the mutant tissues with respect to somatic embryogenesis. Eleven proteins (group 7) are detected specifically in the wild type tissues and their presence could be related to an inhibition of the somatic embryogenesis ability.