조경수목(造景樹木)의 대기오염물질(大氣汚染物質)에 대한 방어기능(防禦機能) (I) - SOD 활성(活性)을 중심으로 -

Resistance Functions of Woody Landscape Plants to Air Pollutants (I) - SOD Activity -

조경수목(造景樹木)들의 대기오염물질(大氣汚染物質)들에 대한 감수성(感受性) 및 저항성(抵抗性)을 규명하기 위해서 야외조사(野外調査)와 실내실험(室內實驗)을 통하여 엽내(棄內) 유황함량(硫黃含量)과 superoxide dismutase(SOD) 함량(含量)을 측정(測定) 분석(分析)하였다. 전(全) 수종(樹種)에서 엽내(棄內) 유황함량(硫黃含量)과 SOD 활성간(活性間)에 정(正)의 상관(相關)을 나타내었다. 식물체(植物體)가 오염물질(汚染物質)에 대하여 자체방어(自體防禦)를 위하여 초기(初期)에는 효소활성(酵素活性)을 증대(增大)시키지만, 식물체(植物體)의 수용한계(收容限界)를 넘을 때는 오히려 효소(酵素)의 실활(失活)과 함께 식물체(植物體)가 피해(被害)를 받았다. 활엽수(闊葉樹)는 대기오염물질(大氣汚染物質)의 정화능력(淨化能力)이 큰 반면 침엽수(針葉樹)는 오염물질(汚染物質)에 대한 방어기능(防禦機能)이 크게 나타났다. 엽내(葉內) SOD 활성(活性)은 비오염지역(非汚染地域)과 오염지역간(汚染地域間)에 차이(差異)가 뚜렷하였는데, SOD 활성(活性)은 활엽수(闊葉樹)에 비하여 침엽수(針葉樹)에서 높게 나타났으며 묘목(苗木)보다는 성목(盛木)에서 높았고, 소나무보다는 잣나무에서 활성(活性)이 높았으며, 튜립나무는 은행나무와 양버듬나무보다 낮은 것으로 나타나 SOD 활성(活性)이 높은 것이 대기오염물질(大氣汚染物質)에 대한 내성(耐性)이 강(强)함을 알 수 있었다. 고유(固有)의 SOD 활성(活性)이 높은 소나무 2년생(年生)잎과 잣나무 1, 2년생(年生)잎에서는 $SO_2$ 처리농도(處理濃度)가 강(强)해질수록 SOD 활성(活性)이 증가(增加)하였으나, 고유(固有)의 SOD 활성(活性)이 나은 수종(樹種)은 저농도(低濃度(0.5ppm)처리(處理)에서는 증가(增加)하고 고농도(高濃度) 처리(處理)에서는 감소(減少)하는 경향(傾向)이었다.

This study was conducted to determine the toxic effects of air pollutants on landscaping trees, Pinus densiflora, Pinus koraierasis, Ginkgo biloba, Liriodeytdron tulipifera, Platanus occidentalis and their resistance to the pollutant toxicity in urban and industrial regions of Seoul and Taejon, Korea. Total sulfur content and superoxide dismutase activity were analysed in tree foliage of Pinus densiflora, Pinzes koraiensis, Ginkgo biloba, Liriodendron tulipifera, Platanus occidentalis. In addition, SOD activity was analyzed in the foliage of tree seedlings, i.e. Pinus densijlora, Pinus koraiensis, Ginkgo biloba, Liriodendron tulipifera, with the lurnigation of $SO_2$ in gas chamber 4 hours a day for six days. In all species total sulfur content and SOD activity had a positive correlation. Air pollutants accumulated in tree tissues were supposed to enhance the enzyme activity like SOD providing with the resistance mechanisms. Trees under the air pollution stress increased enzyme activity to develop internal self-resistance against pollutants, but after a critical point enzyme-activity decreased gradually and resulting in injury after all, Deciduous trees had greater filtration capacity than conifers and coniferous trees showed greater resistance against air pollutants than deciduous species. Foliage SOD activity was higher in polluted area than in unpolluted area for most species. Coniferous species and mature trees had higher SOD activity than deciduous seedlings. Especially Pinus koraiensis, Ginkgo biloba and Plcatanus occidentalis had higher SOD activity than other species. The tree species with the high SOD activity showed strong resistance against air pollutants. In 2nd-year needles of Pinus densiflora seedlings and current and 2nd-year needles of Pinus koraiensis seedlings containing high native SOD activity, SOD activity increased with the increase of $SO_2$ level. But in seedlings containing low native SOD activity, SOD activity increased at 0.5ppm $SO_2$ level while it decreased at 1.5 and 2.5ppm $SO_2$. Changes of SOD activity was different between species and in most species SOD seemed to participate in resistance mechanism.