Vicilin-like seed storage proteins in the gymnosperm interior spruce (Picea glauca/engelmanii)

A seed storage protein cDNA was characterized from a library of interior spruce (Picea glauca/engelmanii complex) cotyledonary stage somatic embryos. The deduced amino acid sequence predicts a 448 amino acid (50 kDa) polypeptide with 28-38% identity with angiosperm vicilin-like 7S globulins. XXC/G codon usage is low (47%) relative to monocot angiosperms while pairwise comparisons show that spruce, monocot, and dicot vicilins are approximately equal in amino acid divergence. Although small by comparison, the spruce vicilin contains an N terminal hydrophilic region characteristic of angiosperm 'large' vicilins. Genomic Southern blotting predicts that the cDNA is encoded by a gene family.