An electrophoretic analysis of the seed proteins from Pinus monticola and eight other species of pine

Abstract

The major storage proteins of mature Pinus monticola Dougl. seed megagametophytes are crystalloids and are only completely soluble in buffer solutions if sodium dodecyl sulphate is present. These insoluble proteins-constitute 50% of the storage reserve in the seed. Crystalloid proteins are found in embryonic axes also and are a major protein reserve in mature seeds from all other Pinus species examined. These proteins in their nonreduced form have molecular masses of 51 – 55 kilodaltons (kDa) and in reduced form migrate on polyacrylamide gels as two distinct groups of proteins, one in the molecular mass range 31 – 34.5 kDa and the other in the 21.5 – 22.5 kDa range. The pine crystalloid proteins are not glycosylated and have similar solubility, structural, and size characteristics to crystalloid proteins found in other seed types, such as Ricinus communis and Cucurbita species. However, they are immunologically different from the crystalloid proteins of R. communis. In general, the soluble protein gel profiles vary considerably among the species. Some similarities do exist; in particular, a group of proteins in the 27 – 29.5 kDa molecular mass regions of polyacrylamide gels is common to all Pinus species examined. The soluble proteins are not glycosylated.