Browsing by Author "Pérez, FJ"

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    Gibberellic acid stimulation of isoperoxidase from pedicel of grape
    (1998) Pérez, FJ; Gomez, M
    Soluble peroxidase activity from pedicels of cv. Thompson seedless grape was highly stimulated by post-bloom gibberellic acid (GA(3)) applications to vines. This stimulation was dependent on the dose employed and increased with berry ripening. In control vines, i.e. non GA(3) treated, the level of peroxidase activity remained constant during; berry ripening. Isoelectrofocusing (IEF) analysis of soluble peroxidases from pedicel extracts performed ina 3-10 pH range, showed the presence of a main band that corresponded to an acidic isoperoxidase of (pI 3.5) and the presence of a minor band of (pI 3.9). It is a well-known fact that GA, applications to cv. Thompson seedless grape beside producing berry enlargement cause berry-drop which has been associated with pedicel thickening. Here we found a positive correlation between pedicel thickness and peroxidase activity within the rates of GA, used. The involvement of the acidic isoperoxidases in pedicel thickening and its relation to berry-drop are discussed. (C) 1998 Elsevier Science Ltd. All rights reserved.