Abstract
The level of soluble proteins and the total activities of 14 enzymes were determined in embryo and megagametophyte tissues of jack pine (Pinus banksiana Lamb.) seeds during imbibition and germination. For embryos, enzyme activities were low in the dry seed and during imbibition but increased rapidly upon germination following emergence of the radicle and to the end of the sampling period of 13 days. For gametophytes, enzyme activities generally increased at a slower rate than embryos, with highest activity present for seeds after 8–10 days of germination. Levels of soluble protein in the gametophytes were highest shortly after emergence of the radicle, while for the embryos levels were highest at the end of the germination period.