The Metabolism of Phloem Isolated From Grapevine

Abstract

Small slices of phloem tissue have been isolated from grapevine canes and cultured in sugar-buffer solutions, and measurements made of the respiration rate and of the changes of sugar concentration in the tissue. Calculations from these measurements of the permeability of the tissue to sucrose, and of the rate of sucrose synthesis from glucose and fructose, show that the phloem is not very different from other plant tissue in either activity. The bearing of these findings on our knowledge of the translocation of carbohydrates by the phloem is discussed.