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The extractable protein in bark tissue of one-year-old shoot of gingko trees (Ginkgo biloba L.) declined dramatically during spring growth, while amino acids increased. The regrowth in the spring is characterized by the mobilization of reserves from the storage tissue and the transfer of solubilities derivatives to the growing parts. The proteins and amino acids were shown to change greatly during early stage of regrowth. The proteins contributed the greater part of the storage nitrogen decreased at the beginning of growth. On the other hand, the amino acids in the bark increased proportionately to the decreased protein. At 30℃, the rate of increase of amino acids in the bark was higher than that of 20℃ and 25℃. The content of amino acids in intact shoot increased much as compared with the shoots of which buds were excised. The contents of protein in intact shoots at 30℃ decreased more rapidly than those of excised shoots at 20℃ and 25℃, indicating that it eras influenced by the regulator which may be presented in buds and by the higher temperature. All three groups of protein I, II and III which were separated with diethylaminoethyl (DEAE)-cellulose column chromatography decreased rapidly after onset of sprouting. Polyacrylamide gel electrophoresis of the proteins at the dormant and beginning of growth stage exhibited the changes of the protein, showing the shift of protein peaks from higher to molecular weight ranges. However, the majority of proteins showed little evidence of net breakdown during early spring growth.
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