The location of Na~+ influx into rice roots and Na~+ transport from root to shoot

摘要

Through ~(22)Na~+ trace trials and multi-compartment transport box experiments, Na~+ influx into different root zones and transport to the shoot were studied. The Na~+ influx rate of branched roots was higher than that of un-branched roots, especially in external solution with higher Na~+ concentration solutions. The rate of uptake in younger branched root was lower than in mature branched roots. The Na~+ taken up by mature branched roots was transported to the shoots more quickly than that from the other root zones. The further the uptake was from root apex, the faster the transport to the shoot. In the moderate external solutions (50mM), Na~+ influx rate, Na~+ transports rate to the shoot and Na~+ concentration in the shoots were not affected by the Ca~(2+). But in the external solution with higher Na~+ concentration solution (100 mM), Na~+ transport to the shoot was inhibited 10%, and Na~+ influx rate was inhibited nearly 50%. The mature lateral root zone was the most important in Na~+ influx and transportation because it has larger epidermal area and excellent vascular bundle.