[Effects of lanthanum on root membrane permeability and nutrient contents in root exudate of rice]

This study showed that when lanthanum was in lower concentration (< or = 50 microg x ml(-1)), the membrane permeability of rice root was stabilized by decreasing the electrolyte exosmosis, and the contents of K+, Ca2+, P and H+ in root exudate were lower than the control; while the concentration of La3+ was in the range of 100-400 microg x ml(-1), the electrolyte exosmosis was reduced in the first 6 hours, and then significantly increased. When the concentration of La3+ was over 500 microg x ml(-1), the electrolyte exosmosis was continuously enlarged because of the destruction of the membrane. Under this condition, K+, Ca2+, P and H+ in root exudate were higher than the control. It could be concluded that the concentration of 50 microg x ml(-1) La3+ was safe to rice growing.