MECHANISM OF HORMONAL-REGULATION OF POTATO (SOLANUM-TUBEROSUM L) TUBER DORMANCY

The transition of potato tubers from dormancy to growth is connected w ith quantitative and qualitative changes in the content of endogenous growth regulating substances. These changes clearly influence the main metabolic reactions (RNA and protein synthesis, plasma membrane funct ioning, cytoplasmic Ca2+ content) in tuber cells. Growth regulating su bstances influence in vitro the incorporation of labelled precursors i nto protein and into different RNA fractions. This influence differs a t different stages of the storage period. The treatment of plasma memb rane fraction with gibberellic acid or abscisic acid leads to binding of these phytohormones to some membrane protein and to changes in memb rane surface structure, Short-term incubation of potato tuber tissues with gibberellic acid or abscisic acid activates membrane-bound bound protein kinase C and changes Ca2+ content in the microsomal fraction. The possible mechanism of hormonal signal transduction in plant cells is discussed.