Rhythmic motions of plants - Measuring rotational movements of the root and cell turgor pressures

In order to investigate the mechanism of rhythmic motions of the plant, which is self-generated in response to its environment, a new measuring system of the rhythmic motion of the root was developed. This system can automatically record 3-dimensional motions of the root. To measure movements of the root with a high accuracy without actual contact, image processing was applied to this system. Furthermore, in order to examine plant cell turgor pressure changes, which are relative to the rhythm formation, they developed a new measuring system of cell turgor pressures, installed two pressure probes. As a result, about 1,2h cycle was observed in the rotational motion of roots, using the measuring system. And rhythmic motions at the main root disappeared when its tip was removed. In addition, it was found that turgor pressures of the main root showed periodic changes and that became synchronized with its environments when light and dark cycles, whose period was 2h, was provided.