Movement within leaves and plants of 14C applied as 14CO2

Abstract

A study was carried out to determine how 14C applied as 14CO2 to a localized area of the leaf for 5 min moved to the rest of the leaf during the treatment period. It was concluded that 14CO2 diffuses from the application area to the rest of the leaf where it is fixed photosynthetically in the position detected by whole leaf autoradiography. These conclusions were deduced from experiments on darkening a portion of the leaf, comparing the radioactive compounds in treated and untreated areas of the leaf, and by using variegated Pelargonium leaves. Using the darkening technique, 14CO2 movement in the stem of soybean was not detected for 15 min after treatment of a primary leaf with 14CO2 in the light.