Visualizations of photoassimilate translocation in intact eggplant fruit using a positron-emitting tracer imaging system

Kikuchi, Kaori*; Kawachi, Naoki; Ishii, Satomi; Suzui, Nobuo; Ito, Sayuri; Ishioka, Noriko; Honda, Ichiro*; Fujimaki, Shu

Positron-emitting tracer imaging system (PETIS) noninvasively visualizes movement of C-labeled photoassimilate in plants. So we fed CO to a leaf and monitored the translocation of C-labeled photoassimilate into the eggplant fruit by PETIS. Continuous images of the translocation of [C]photoassimilate from the leaf to the fruit and inside the fruit were produced, with a shorter time resolution than reported previously. C signal intensity in the fruit increased gradually, and its distribution was not uniform. The fruits were sliced after PETIS measurement and exposed to the imaging plates of a bio-imaging analyzer system. The resultant images indicated that translocation of photoassimilate within the fruit was not uniform. Furthermore, we successfully estimated the velocity of photoassimilate translocation in the peduncle and changes in the rate of translocation of photoassimilate in the fruit.