$SO_2$에 대한 양버즘나무의 내성을 증대시키고자 생장왜화제인 uniconazole을 토양주입하고, 그 내성 기작을 superoxide dismutase와 peroxidase의 역할과 관련하여 조사했던 바 다음과 같은 결과를 얻었다. Uniconazole은 농도가 높아질 수록 간장, 엽면적 및 T/R율(率)을 현저하게 감소시키고, 엽록소 농도와 superoxide dismutase 및 peroxidase활성을 현저하게 증가시켜 $SO_2$ 처리에 의한 가시피해를 유의성있게 경감시켰다. Diethyldithiocarbamate를 엽면살포하였을때, superoxide dismutase와 peroxidase 활성이 현저하게 불활성화되어 $SO_2$ 처리에 의한 가시피해(可視被害)가 증가되었으며 uniconazole 처리에 의해 증대되었던 $SO_2$ 내성은 diethyldithiocabamate 처리에 의하여 다시 감소되었다. 이상과 같이 uniconazole은 식물생장의 왜화(矮化)에 의한 조직의 치밀화 이외에 SOD와 POD의 활성증대를 통해 $SO_2$에 대한 내성을 증대시킨 것으로 판단된다.
This study was conducted to investigate the phytoprotective effects of uniconazole on $SO_2$ injury in P. occidentalis. The detoxification role of free radical scavengers such as superoxide dismutase (SOD) and peroxidase (POD) was also examined under the conditions of combined treatment with uniconazole and diethyldithiocarbamate (DDTC). Uniconazole drenching significantly reduced the occurrence of visible injuries. Though shoot length, leaf area, and T/R rate were greatly decreased by uniconazole application, the tolerance to $SO_2$ was enhanced through increased chlorophyll content and activities of SOD and POD. Spray of DDTC decreased the activity of SOD and POD resulting in the increase of visible injury. Plant tolerance to $SO_2$ induced by uniconazole application was reduced by the additional application of DDTC. These results indicate that plant tolerance to $SO_2$ induced by uniconazole is associated with the reduction of vegetative growth as well as the increase in free radical scavengers such as SOD and POD.
