EN
ACPase activity was localized in the apoplast of pea root nodules under phosphorus deficiency. Pea plants (Pisum sativum L. cv. Sześciotygodniowy) where inoculated with Rhizobium leguminosarum bv. viciae 248 and were cultured on nitrogen-free medium with phosphate (-N/+P) or phosphate-deficient (-N/-P) one. In comparison with control nodules, P-deficient nodules showed the increase of ACPase activity in plant cell walls and the infection threads. The increase in bacterial ACPase activtty under P-deficiency may reflect higher det mand for inorganic phosphorus that is necessary for bacteria multiplication within the infection threads. The increase of ACPase activity in nodule apoplast under P stress may enlarge the availability of phosphate for plant and bacteria.