Invasive Species Compendium

Detailed coverage of invasive species threatening livelihoods and the environment worldwide

Abstract

Developmental gene expression in conifer embryogenesis and germination I. Seed proteins and protein body composition of mature embryo and the megagametophyte of white spruce (Picea glauca (Moench) Voss.).

Abstract

An ultrastructural study of protein bodies of P. glauca showed the presence of globoids and crystalloids embedded in an amorphous matrix. Storage protein composition of isolated protein bodies was examined by SDS-PAGE analysis and compared to that of embryonic and megagametophytic tissue. Crystalloids were shown to be the major storage proteins and were only completely soluble in buffered sodium dodecyl sulfate or 6 smallcap˜M guanidine-HC1. These insoluble proteins constituted up to 70% of the storage reserves in the seed. Crystalloid proteins were found in the megagametophyte and, to a lesser extent, in the embryonic axis, and are a major protein reserve in mature seeds from all other Picea species examined. These proteins in their non-reduced form had MWs of 57 kDa and in reduced form migrated as 3 distinct groups of proteins with MWs of 42, 34.5-35 and 22.5-23 kDa. The soluble protein gel profile showed that a group of proteins in the 27-30 kDa molecular weight region are the major proteins in the buffer soluble fraction and are common to all Picea species examined. None of the proteins of P. glauca appeared to be glycosylated.