Effect of enhanced UV-B radiation on polyamine contents and the activity of related enzymines in rice (Oryza sativa L.)
UV-B辐射增强对水稻多胺含量及其相关酶活性的影响

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.