[Effect of Ce (III) on photochemical reaction activity in soybean seedlings under supplementary UV-B radiation stress].

ABSTRACT

Effect of Ce(III) on photochemical reaction activity in soybean seedlings exposed to ultraviolet-B radiation (UV-B, 280 - 320 nm) was studied with hydroponics under laboratory conditions. The results showed that CeCl3 (20 mg x L(-1)) could improve photosynthesis action and net photosynthesis rate, the Mg(2+) -ATPase activeness, the photosynthetic phosphorylation active and stimulate the activity of Hill reaction (23.2% - 14.3%). And Ce(III) could alleviate the inhibition of UV-B (T1 = 0.15 W x m(-2) and T2 = 0.45 W x m(2-)) on the four indexes above in plants to a certain extent, and the decreasing degrees of the indexes under Ce(III) and UV-B stress were lower than those only under UV-B stress, which were 36.6% - 15.9% [Ce(III) + T1 ], 65.6% - 33.2% [Ce(III) + T2], 50.9% - 23.3% (T1), 77.3% - 51.4% (T2) respectively. The dynamic data indicated that Ce(III) could alleviate the inhibition of UV-B on the four indexes above while promoting without UV-B stress. The results showed that Ce(III) could alleviate the decrease in the net photosynthesis rate by lightening the damage of the photochemical reaction activity on the soybean seedings under UV-B stress.