Abstract
Reeds are perennial grasses which can grow in saline and keep shoot Na+ content low. To analyze Na+ distribution in reed, radioisotope tracer experiments were carried out. More 22Na was distributed into stem and leaf sheath during short or long uptake periods. For pulse chase experiments, plants were loaded with 22Na for 1 week under saline condition and transferred to chase solution with salt. The radio activities in root were quickly decreased during chase period, but these in shoot were not significantly decreased. Considering that shoot Na+ content of reed reach the maximum level at three days after salt treatment, our results suggested that reeds could keep Na+ content in shoot low due to restriction of Na+ transport from root to shoot rather than to retranslocation of Na+ from shoot. We will also discuss the real-time Na+ behavior using PETIS (Positron Emitting Tracer Imaging System) under continuous saline stress.
