UV-B辐射增强对水稻多胺含量及其相关酶活性的影响

试验研究表明,处理前期(7～14d)UV-B辐射增强使“汕优63”水稻精氨酸脱羧酶(ADC)、鸟氨酸脱羧酶(ODC)和S-腺苷蛋氨酸脱羧酶(SAMDC)活性分别增加165.74％、104.60％和89.60％,“南川”(NC)运3种酶活性分别增加59.91％、41.30％和23.68％,新品系“IR_(65600-85)”在UV-B辐射胁迫下多胺脱羧酶活性表现与前2品种略不同,即ADC和ODC活性分别提高115.93％、14.45％,而SAMDC活性下降33.01％。处理后期(21～28d)随UV-B辐射累积量的增加,这3种酶活性均有所下降,其中ODC和SAMDC活性降幅大于ADC,其中“汕优63”ADC、和ODC活性分别比对照增加89.72％、3.71％,“南川”则分别增加73.95％、27.38％,“IR_(65600-85)”ADC活性增加94.41％,ODC、活性却下降13.57％。处理后期(21～28d)3类水稻“汕优63”、“南川”和“IR_(65600-85)”SAMDC分别下降40.06％、19.20％和38.21％。多胺氧化酶(PAO)活性变化趋势则相反,即处理前期(7～14d)呈不同程度下降趋势,处理后期(21～28d)则呈极显著上升趋势,其结果引起多胺(PA)含量特别是腐胺(Put)含量明显上升。水稻对UV-B辐射增强的反应具有基因型差异。

Effect of enhanced UV-B radiation on polyamine contents and the activity of related enzymines in rice (Oryza sativa L.)

Experimental results show that when the plants are exposed to enhanced UV-B radiation for 7 ~ 14 days,the activities of agrininc decarboxylase (ADC),ornithine decarboxyiase (ODC) and s-adenosylmethionine decarboxylase (SAMDC) in leaves are increased by 165.74%,104.60% and 89.60% in "Shan You63" (Sy63),59.91%,41.30% and 23.68% in "Nancheum" (NC) and 115.93%,14.45% arid-33.01% in IR65600-85,respectively.However,the three enzymic activities turn to decrease with the treatment time increasing (21~28d) and the decreased extents of ODC and SAMDC are much higher than that of ADC,.The activities of ADC and ODC are increased by 89.72% and 3.71% in Sy63 and 73.95 % and 27.38 % in NC exposed to UV-B radiation for 21 ~ 28 days.The activity of ADC is also increased by 94.41% but ODC activity is decreased by 13.57% in the leaves of IR65600-85 compared with the controls.As far as SAMDC is concerned,the enzymic activities in Sy63,NC and IR65600-85 are reduced by 40.06%,19.20% and 38.21% respectively when they are exposed to enhanced UV-B radiation for 21~28 days.The reverse is true in the case of poly-amine oxidase (PAO),indicating its lower activity in earlier treatment courses (7~14d),but much higher activity in late courses (21~28d) compared with the controls.These in turn result in the increased contents of polyamine (PA),especially putrescine (Put) and the results of the experiment have shown their differences in diverse rice genotypes.