Ce(Ⅲ)对UV-B辐射胁迫下大豆幼苗光化学反应的影响

用水培法研究Ce(Ⅲ)对UV-B辐射胁迫下大豆幼苗光化学反应的影响.结果表明, 20 mg·L^-1 CeCl₃使大豆幼苗净光合速率(Pn)、Hill反应、Mg²⁺-ATPase活性与光合磷酸化活力4项指标较对照提高23.2%～14.3%; 有效抑制UV-B辐射(T₁=0.15 W·m^-2和T₂=0.45 W·m^-2)胁迫下4项指标下降, 4项指标降幅［Ce(Ⅲ)+T₁为36.6%～15.9%,Ce(Ⅲ)+T₂为65.6%～33.2%］小于对应的UV-B辐射组(T₁为50.9%～23.3%,T₂为77.3%～51.4%). 动态变化显示, Ce(Ⅲ)减缓了胁迫期4项指标的下降趋势,促进了恢复期4项指标上升幅度. 说明Ce(Ⅲ)通过减轻UV-B辐射对大豆幼苗光化学反应的伤害, 遏制UV-B辐射胁迫下大豆幼苗Pn下降.

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

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.