O_3浓度升高和UV-B辐射增强对大豆叶片抗氧化酶活性及POD同工酶的影响

Combined Effects of Elevated O_3 Concentration and UV-B Radiation on Anti-Oxidative Enzymes Activities and POD Enzymes Isozymes of Soybean

以大豆品种铁丰29为材料,利用开顶式气室(OTCs)研究了O3浓度升高和UV-B辐射增强单独胁迫及复合胁迫下大豆叶片抗氧化酶(SOD、POD和CAT)活性及POD同工酶谱带的变化。结果表明:O3处理大豆叶片SOD、CAT和POD活性均低于对照;UV处理下,大豆叶片SOD、CAT、POD活性也均低于对照,但基本高于O3处理;O3及UV复合处理下,加剧了SOD、CAT、POD活性的减弱。对POD同工酶研究发现,在分枝期,O3处理产生1条新谱带,开花期和结荚期均比分枝期多2条谱带,并且受胁迫处理的POD酶谱带与对照相比颜色较浅,说明在整个生育期,胁迫处理下的大豆叶片POD同工酶活性受到抑制。

During the last several decades, significant reductions in the concentrations of stratospheric ozone （ 03 ） have been reported. The decrease of ozone concentration causes an increment of ultraviolet-B radiation to earth surface. The objective of this experiment is to reveal the toxicological mechanism under elevated ozone concentration and UV-B radiation singly or in combination on plant anti-oxidation enzymes activities and POD isoenzyme. Open-top chambers （OTCs）were utilized to investi- gate change of anti-oxidation enzymes activities and POD isoenzyme band in soybean（ Glycine max） leaves under elevated ozone concentration and UV-B radiation singly or in combination treatment. The results of anti-oxidation enzymes activities indicated that either 03 treatment or UV-B treatment induced a decrease on SOD, POD and CAT, and in the combined stress, anti-oxida- tion enzymes activities had intensified this trend to a certain degree. The result of POD isozyme band showed that a new band appeared under 03 treatment in branching stage and two new bands appeared in flowering stage and podding stage compared of branching stage, and the shade of color of POD isoenzyme bands was lighter compared to CK treatment. It was suggested that in all growth period, POD isoenzyme activity was inhibited under combined stress.