The Uptake of Orthophosphate and Its Incorporation into Organic Phosphates Along Roots of Pinus Radiata

Abstract

An automatic scanning-recording method showed that relative incorporation of [32P]orthophosphate along sterile pine roots into both the nucleic acid fraction and the phospholipid-phosphoprotein fraction was usually much greater in the apical 1-and 2-cm segments than in the remainder of the root. Relative incorporation into phosphate fractions was modified considerably by the phosphate uptake and phosphate status at different parts of the root_ Relative incorporation into the readily acid-soluble fraction was greatest at sites of greatest phosphate uptake along the root, and was less with phosphate-deficient plants than with high-phosphate plants. Description of root behaviour as an average of the entire root is inadequate and is likely to lead to erroneous interpretation of nutrient uptake and use by roots_