Experiments using rice plants (Oryza sativa L.) were conducted to examine uptake of 14C-acetic acid via the root and 14C behavior on the root surface. For hydroponics, three types of rice plants were cultured with 14C-acetic acid solution: complete plant, half-rooted plant, and non-rooted plant. Also, for the root incubation experiment, sterilized root and non-sterilized root were incubated with 14C-acetic acid solution. The 14C radioactivities in the plant parts and solution were measured. Non- and half-rooted plant had 14C radioactivity in their aerial part, but the complete plant did not. The trends of radioactivity levels in the solution were directly opposite to those of plant root biomass. A high level of 14C radioactivity was observed on the entire root surface of non-sterilized root in the incubation experiment, and 14C radioactivity in the solution also remarkably decreased from 7 h to 96 h after the 14C addition. These results suggest that the amount of 14C-acetic acid absorbed by the plant through the roots is very small. However, the plant absorbs 14C-acetic acid through breaks in the roots. Once 14C-acetic acid is inside the plant, it immediately transfers to the shoots. Degradation of 14C radioactivity in the solution and 14C fixation on the root surface arise from the context of microbial activities.

This content is only available via PDF.
You do not currently have access to this content.