Nitrate and Other Anions in the Rice Phloem Sap

The anionic composition was determined for pure rice phloemsap which had been collected from brown planthopper styletsby cutting them with a YAG laser beam. The most abundant inorganicanion was Cl^– at 52.1 mM. PO₄^3– and SO₄^2–were found at 8.1 mM and 1.8 mM, respectively. NO₃^– waspresent at 1.9 mM when the rice had been grown with nutrientsolution containing 0.35 m of NO₃^– The phloem sap alsocontained malic, succinic and citric acid at 7.3, 3.0 and 3.2mM respectively. Small amounts of other organic acids were alsofound. (Received October 4, 1984; Accepted December 14, 1984)