The system consisting of a few proportional detectors with appropriate electronic components was earlier developed for in vivo studies of long distance transport in whole maize seedlings. ¹⁴CO₂ assimilation rate (Pa), time of radioactivity appearing in the loading region (AT), transport speed in the leaf (TSl), transport speed between the leaf and the roots (TSr), the maximum radioactivity values detected in the leaf below the feeding area (Rl) and in the mesocotyl (Rr) from leaves to roots in maize seedlings were calculated from the obtained temporal profiles of radioactivity. The study was undertaken to follow the changes in separate steps of long distance transport in maize seedlings as affected by two light irradiances and application of p-chloromercuribenzenesulphonic acid and fusicoccin, with the aim to investigate different steps of long distance transport, particularly phloem loading. The method used allows to study in vivo the different aspects of long distance transport in maize seedlings, both qualitatively and quantitatively. It was shown that the characteristics obtained from the radioactivity profiles corresponded to different steps of long distance transport, as assimilate synthesis, phloem loading, and phloem translocation. It was also demonstrated that although active phloem loading participate in assimilate export from the leaves, assimilate transport along the maize seedling might undergo accordingly to assimilate gradient, particularly under light irradiance higher than during the growth.
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.