INOSITOL 1,4,5-TRISPHOSPHATE DISTRIBUTION IN LYCOPERSICON-ESCULENTUM MILL SEEDLINGS CULTIVATED IN-VITRO UNDER DIFFERENT CONDITIONS

Measurements of inositol 1,4,5-trisphosphate (Ins1,4,5-P-3) in cotyled ons, epicotyls and roots of tomato seedlings grown ''in vitro'' either in the light or in the dark indicated that higher concentrations of t his signal-transducing molecule are contained in hypogeous vs, epigeou s tissues. The same wets observed in induced cotyledon explants grown in the light in the presence of growth regulators. Data concerning pho sphatidylinositol metabolism in seedling roots are also reported. Take n together, our results may be helpful in understanding the role of th e polyphosphoinositide signal system in plants.