Quantitative Studies of Root Development II. Growth in the Early Stages of Development

Abstract

A method has been developed for automatic scanning of plant roots to record accurately and with good resolution sites of uptake and accumulation of radioactively labelled nutrients. This technique was applied to a comparison of phosphate uptake by excised and attached wheat roots. In periods of 2 and of 15 min attached roots absorbed 40-60% more phosphate than did roots excised immediately prior to uptake. These differences could not be ascribed to transpiration nor to translocation in whole plants and hence rapid physiological changes upon excision are suggested. The lower uptake of excised roots occurred in both the apical and the mid-root portions.