Hormone levels and protein patterns in dormant and non-dormant buds of strawberry, and induction of bud break by gibberellic acid

  • Hala F. S. Ahmed Department of Botany, Faculty of Science, Ain Shams University, Cairo, Egypt
  • Mohamad Imam Ragab Department of Horticulture, Faculty of Agriculture, Ain Shams University, Egypt.
Keywords: Abscisic acid, auxin, cytokinin, zeatin, benzyladenine, histology, PAGE-electrophoresis

Abstract

Strawberry runners are characterized by the occurrence of a dormant bud followed by a consequent non-dormant bud. Dormant buds were found to contain relatively low levels of endogenous gibberellic acid (GA3) and enhanced levels of abscisic acid (ABA), as compared with non-dormant buds. The lower contents of GA3 in the dormant buds were also accompanied by attenuated levels of auxin (IAA) and cytokinins (zeatin and benzyladenine). Exogenous application of GA3 (50 ppm) to the latent buds could achieve 97% break of their onset of dormancy. Histological examination showed that the initial stage of bud formation was similar in the dormant and non-dormant buds. Thus, triggering the burst of a dormant bud by GA3 treatment is assumed to occur in the second developmental stage. Comparison of the proteinbanding patterns in the dormant and non-dormant buds showed a slight difference in the number of protein bands, but a wide variation in their types. The results suggest differences in the regulation of gene expression, perhaps controlled mainly by ABA in the dormant buds and GA3in the active state.
KEY WORDS: Abscisic acid, auxin, cytokinin, zeatin, benzyladenine, histology, PAGE-electrophoresis
Egyptian Journal of Botany Vol.5 2003: 35-42
Published
2005-03-17
Section
Articles

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eISSN: 1110-6859