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Loblolly pine seed dormancy. I. The relationship between protein synthesis and the loss of dormancy

Schneider, Wendy L., Gifford, David J.
Physiologia plantarum 1994 v.90 no.2 pp. 246-252
Pinus taeda, buffers, cooling, lipid content, molecular weight, protein content, protein depletion, protein synthesis, proteins, seed dormancy, seeds
Embryos from the mature unstratified loblolly pine (Pinus taeda L.) seeds used in this study were nondormant: however, they failed to germinate in situ because of constraints imposed by the surrounding tissues. During a stratification period of 35 days of moist chilling at 2°C, seed germinability increased from 19 to 76%. The total lipid content of the megagametophyte did not change during stratification, whereas the total protein content of both megagametophyte and embryo was more variable. The rate of synthesis of buffer soluble proteins in these two tissues increased and electrophoretic analysis showed that while similar proteins were synthesized during the stratification period, changes in the patterns of synthesis of some proteins did occur. In both the embryo and megagametophyte the synthesis of a set of proteins with molecular masses below 46 kDa decreased markedly after 14 days of chilling (DOC). In the megagametophyte, the synthesis of a more diverse set of proteins with molecular masses ranging from 16 to 78 kDa increased after 14 DOC. It is noteworthy that these changes in the patterns of protein synthesis coincided with the greatest relative increase in seed germinability of 35%.