Ce(Ⅲ)对UV-B辐射胁迫下大豆幼苗光化学反应的影响

Effect of Ce(Ⅲ) on Photochemical Reaction Activity in Soybean Seedlings Under Supplementary UV-B Radiation Stress

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-1CeCl3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=0.15W.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 exposed to uhraviolet-B radiation （UV-B, 280 - 320 nm） was studied with hydroponics under laboratory conditions. The results showed that CeCl3 （20 mg·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（Tt = O. 15 W·m^-2 and T2 = 0.45 W·m^-2 ） on the four indexes above in plants to a certain extent,and the decreasing degrees of the indexes under Ce（ m ） 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 J, 50.9% - 23.3% （%）, 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.