Isotypes of 78 kD Streptavidin Biotin-binding Proteins (SBP) during Initial Germination of Dark-grown Pea (<i>Pisum sativum</i> L.) Seedlings

Abstract

In this study two dimensional page and western blotting have been used to investigate the status of isotypes of 78 kD streptavidin biotin-binding proteins (SBP) in dry seeds, germinated seeds and a combination with its different plant parts including stems, plumules and roots of pea ( Pisum sativum L. var Alaska). Dry seeds contain 21 isotypes, five of them are almost separated with isoelectric point (PI) 5.66, 5.82, 5.88, 5.91 and 6.55, and four of them are partially separated with pI values 5.92, 5.94, 5.96 and 5.98, the remaining forming unseparated isotypes mixture with pI values varied from 5.07 to 6.50. Embryos of forty hours germinated pea seeds showed 9 different biotin isotypes with pI values from 5.76 to 6.64. Stems parts of seventy two hours germinated pea seeds showed highest expressed 11 biotin isotypes with pI values from 5.60 to 6.65, whereas the plumules parts showed 10 isotypes with pI values from 5.78 to 6.46. And the root parts showed 5 separated isotypes with PI values from 5.72 to 6.00 and unseparated isotypes mixture with a pI values ranged from 6.27 to 6.67. These results suggest that the isotypes of 78 kD streptavidin biotin-binding proteins in dormant and germinating pea seeds might play a role in embryo longevity and early seed germination.