ECHOTOXICOLOGY OF ULTRA VIOLET RADIATION ON EARTH ENHANCED BY DEPLETION OF STRATOSPHERIC OZONE

平流层臭氧的消耗被认为会增强地球上的紫外线辐射，并破坏地球的生态系统。研究了紫外光辐射对植物的生态毒理作用。A.三叶草的叶绿体部分在其起始阶段催化丙咪胺的脱甲基化。一种商品的叶绿素a在500 nm以上的光照下催化丙咪胺的脱甲基化反应，表明它能产生单线态氧作为反应中间体。为了利用叶绿素a作为光催化剂，发现它在非极性溶剂中很稳定，但在氧化镁上部分分解。辐射对类囊体膜中的叶绿素含量没有影响，但其发光光谱发生了变化，表明类囊体膜的光胁迫。在UV-A辐射下观察到单线态氧的光形成，但随着照射时间的延长而失活。蛋白水解酶抑制剂停止了其失活，表明UV-A辐射诱导了某种蛋白水解酶的产生。

The depletion of of stratospheric ozone is considered to enhance UV radiation on the earth and to destroy its echosystem. Echotoxicolgy of UV radiation was studied for plants.A.The chloroplast fraction of a clover, Trifolium, was found to catalyze the demethylation of imipramine for its starting period. Chlrophyll was suggested to be an active compornent and to lose its catalytic activity spontaneously.B.A commercial chlorophyll a was used for catalytic demethylation of imipramine under radiation of light above 500nm, indicating that it produces singlet oxygen as a reation intermediate.C.In interest to utilize chlorophyll a as photocatalyst, it was found to be stable in nonpolar solvent but decomposed partially on MgO.Chlorophyll a impregnated on MgO gave a hydroxy radical under visible light, indicating its usefulness as photocatalyst.D.Spinach thyarkoid membrane was radiated by UV-A light in interest for its photodamage to plants. The radiation did not affect the amount of chlorophyll contained in it, but its luminescence spectra was changed indicating the photostress of thyrakoid membrane. Photoformation of singlet oxygen was observed in radiation of UV-A,but was deactivated with radiation time. Protease inhibitor stopped its deactivation, suggesting an induction of some kind of protease by UV-A radiation.