增强UV-B辐射对蚕豆叶片微粒体膜一些性质的影响

温室条件下，用0（Control）、8．65kJm－2d－1（TI）及11．2KJm－2d－1（t2）不同剂量的UV－B辐射处理蚕豆幼苗。Ca2 ．ATPase及Mg2 －ATPase的活性在辐射处理期间下降。在处理21d，T1和T2微粒体膜的MDA含量明显高于对照，同时IUFA急剧下降，且呈明显的剂量效应。14及21d时，膜磷脂的含量也明显下降。脂氧合酶（Lox）活性在第7及14天与对照相比都显著升高，而21d后迅速下降。结果表明，增强UV－B对微粒体膜的伤害可能是一方面导致正常酶合成与分解之间的平衡失调，另一方面导致了膜脂过氧化作用。

Effects of Enhanced UV-B Radiation on Properties of Microsomal Membrane of Broad Beau Leaves

The properties of micrososmal membrane of broad bean (Vicia fabaL. ) leaves exposed to UV-B radiation(Control : 0 kJ m--1 d--1; T1: 8.65 KJm-l d-1; T2: 11.2 kJ m--1 d--1) werestudied under peen-hourse conditions.The achvities of Ca2 -ATPase andMa2 -ATPase decreased during thetreatment (Figs. 4, 5) and after 21 daysof UV-B radiation the content of MDAwas higher than the control and increasedby 68.7% in T1 and 71.5% in T2 respectively (Fig. 1 ). Meanwhile, IUFAdecreased drastically (Table 2), and wasconsisted with the strength of the UV-Bdosages, indicating that lipid peroxidation occurred . The total phospholipid contentwas higher on the 7th day tinder T1 andT2 beatments but were lower on the 14thday and the 21th day(Fig. 2). The activity of lipoxygenase was higher on the7th and the 14th day and were muchlower on the 21th day than the control(Fig. 3 ). The results suggest that theloss of activity of some functional enzymes and the lipid peroxidation were themain reasons for the damage of the microsomal membrane.Keywoad: UV-B (280 ~ 320 nm ), Vicia faba L.,microsomal membrane, membrane damage