Endogenous polyamines in the pericarp and seed of the grape berry during development and ripening

The levels of free, perchloric acid-soluble conjugated and perchloric acid-insoluble bound polyamines were determined in pericarp and seeds of 'Muscat Bailey A' grapes (Vitis labrusca L. x Vitis vinifera L.) during development and ripening. In both, the pericarp and seeds, putrescine was the predominant polyamine in the three fractions, and the bound polyamine level was the highest of the fractions. In the pericarp, the levels of free putrescine and spermidine were higher during early development. In all fractions, all polyamines in the pericarp increased 30 days after full bloom; the increase was greatest in conjugated polyamines, and least in free polyamines. These increases coincided with an increase in the levels of free polyamines in the seeds. Polyamine levels in all fractions were almost constant during ripening. In the seed, the levels of free polyamines increased when the levels of conjugated polyamines decreased at 30 days after full bloom. The levels of conjugated and bound polyamines increased 50 days after full bloom, with a decrease in the free polyamine level. The inverse relation between the change in the levels of free polyamine and of conjugated and/or bound polyamines was a peculiar feature to the seeds. (C) 2000 Elsevier Science B.V. All rights reserved.