Effects of La(NO_3)_3 on Photosynthetic Light Reaction in Chloroplast of Tobacco Plants

The contents of REE(rare earth elements) in different organs of tobacco are determined by ICP MS. The results indicated: ① in Hoagland solution with La(NO 3) 3, the content of REE in tobacco plants was in the order as rootleafstem. ② the content was enhanced as the concentration of La(NO 3) 3 increased. It has been found that La(NO 3) 3 could increase the activities of Hill reaction, Mg 2+ ATPase and the rate of photophosphorylation in chloroplast of tobacco seedlings when 5 to 50 mg/L La(NO 3) 3 in Hoagland solution were added, and the optimum concentrations of La(NO 3) 3 is in the range of 10 to 20 mg/L but inhibited when the concentrations of La(NO 3) 3 were≥50 mg/L.