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Distribution and Isoenzymes of Aspartate Aminotrans‐f erase in Cotyledons of Germinating Pumpkins
Author(s) -
Splittstoesser Walter E.,
Stewart Sheryl A.
Publication year - 1970
Publication title -
physiologia plantarum
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.351
H-Index - 146
eISSN - 1399-3054
pISSN - 0031-9317
DOI - 10.1111/j.1399-3054.1970.tb08888.x
Subject(s) - germination , isozyme , enzyme , nitrogen , hydrolysis , biochemistry , chemistry , botany , biology , organic chemistry
During germination a steady decline in the reserve protein occurred in dark grown pumpkin cotyledons. By 9 days, 80% of this nitrogen reserve was hydrolyzed but only 50 % was removed from the cotyledons. The remaining nitrogen (30 %) was incorporated into water soluble protein which reached a maximum 9 days after germination. The increase in water soluble protein in pumpkin cotyledons parallel the increase in soluble and particulate aspartate aminotransferase (E.C.2.6.1.1.), suggesting that this enzyme is involved in nitrogen metabolism during germination. Little enzyme activity was found in pumpkin tissues other than the cotyledons. Four anodally moving isoenzymes were found in the soluble aspartate aminotrans‐ferase fraction and 3 anodally moving isoenzymes were found in the particulate fraction. The slowest moving isoenzymes disappeared first during germination.