Translocation III. Experiments with Carbon 14, Chlorine 36, and Hydrogen 3

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Abstract
Short-period (20 and 30-minutes) translocation has been studied in soybean (Glycine max.). Rates of movement of labelled photosynthate (from leaves) or fructose-U-C14 (from petioles) has been compared with HCl36 and THO. Effort to determine any directing influence by specific plant organs were unsuccessful. Removal of root tips and growing points gave variable results; steaming the lower stem reduced the rate of photosynthate into stems; excision below the cotyledon completely stopped the downward movement of all leaf- and petiole-applied tracers. When HC136 is applied, Cl appears to moves as the ion. At moderate light levels, photosynthesis is inhibited in the presence of non-wilting amounts of HC1, as shown by double-labeling experiments with C14O2. Cl movement is reduced also in the light compared to the dark. Simultaneous petiole feeding of THO and fructose-U-C14 results in the expected .movement of fructose, but essentially no movement of THO. T-photosynthate, from leaf-vapor THO feedings, also moves at expected rates, but is accompanied with essentially no THO. Similar results for leaf-vapor feeding were obtained for cumcumber. The data are best explained by a process involving movement of solute without corresponding movement of water as the solvent. On the basis of quantitative comparison, it was concluded that the tracers (except for THO) may be transported by the same type of mechanism, whether fed from solution through cut petioles or through leaves after gaseous application.