THE AGENT OF LATE BLIGHT PHYTOPHTHORA-INFESTANS (MONT) DEBARY INTERFERES WITH FUNCTIONING OF THE GROWTH-REGULATING SYSTEM IN POTATO CELLS

We studied the effect of fungal extracellular metabolites (FEM) of Phy tophthora infestans (Mont.) De Bary on binding of phytohormones with c ytoplasmic membrane preparation (CMP) from potato tubers, and investig ated the action of exogenous phytohormones on binding of FEM with CMP. Parameters of binding of GA and ABA did not change during action of F EM on CMP from freshly harvested tubers, but underwent significant alt eration at the end of the period of dormancy. These changes depended o n the phytohormone used and tbe race of the fungus (compatible or inco mpatible with the corresponding potato cultivar). Gibberellic acid or IAA increased binding of anti-FEM immunoglobulins with CMP, whereas AB A did not alter it. It is concluded that fungal metabolites affect int eraction of phytohormones with the cytoplasmic membrane of tubers. Mor eover, phytohormones affect binding of fungal metabolites-and anti-fun gal and anti-membrane immunoglobulins-with the cytoplasmic membrane.