【摘要】 用缺Cu或Zn,与缺Cu、Zn的木村B营养溶液培养杂交水稻威优48(V₄₈),威优49(V₄₉)与常规稻竹系26(ZX₂₆)幼苗至七叶期。缺Cu的稻苗,上部新生叶（六、七叶）先端扭曲,叶尖枯黄。缺Zn与缺Cu、Zn的稻苗,六、七叶脉间全部褪绿,植株矮小,根系衰退。凡是缺素培养的稻苗,根与叶的超氧物歧化酶（SOD）活性均显著减弱,叶绿体基粒与间质片层明显减少,缺Cu、Zn的叶绿体还出现较大的淀粉“液泡”。经凝胶电泳,显示出水稻SOD有4组活性带,缺Cu或Zn与缺Cu、Zn使迁移率较高的3组活性带的活性明显减弱。更多还原

【Abstract】 This paper reports the effects of Cu and Zn on the SOD activity of rice seedlings, the relationship between SOD activity and structure of thylakoid membranes in chloroplasts, and the possible influence of Cu and Zn on biomembrane through SOD.Seedlings of two hybrid rice (V₄₈, V₄₉) and a conventional rice variety (ZX₂₆) were cultured in Kimura solution B without Cu and/or Zn. At the 7th leaf stage, upper parts of new leaves of Cu-deficient plants twisted and leaf tips turned yellow. However, the main parts of the leaves remained green and the growth of roots and leaves was not significantly inhibited. Under Zn and Cu+Zn stress, the 6th and 7th leaves became yellowish between veins, and plant height, root length and number of white roots were markedly reduced as compared with those of the control （Table 1）.The SOD activities, determined using the method of Giannopolitis and Ries （1977）, were much lower in the roots and leaves of Cu or Zn and Cu+Zn deficient plants （Table 2）. In the polyacrylamide gel electrophoretogram, the SOD showed 4 groups of isoenzymes. The group migrating slowest had only one band but the activity was the highest and was not influenced by the Cu and Zn deficiency, while the activities of the other 3 groups were markedly reduced by the nutrient stress （Fig. 1）. Under electronmicroscope, it was observed that the number of grana, and stroma lamellas were considerably decreased in the chloroplasts of the stressed plants. In particular, some large starch "vacuoles" appeared in the chloroplasts under Cu+Zn deficiency （Fig. 1）.From the analysis of the results, it can be seen that the reduced thylakoid membrance and disorderly arranged lamellas are correlated with the SOD activity under Cu or Zn deficiency. When SOD activity decreases, pepoxidation of lipids occurs in thylakoid membrance containing mainly polyunsaturated fatty acids, which leads to the destruction of some thylakoid membranes. Therefore, it is possible that Cu or Zn deficiency indirectly affects thylakoid membrance by directly influencing SOD activity. Furthermore, the chlorophyll content was not significantly influenced under Cu deficiency, but was obviously reduced under Zn deficiency （Table 1）. This may be due to the inhibition of the biosynthesis of chlorophyll by Zn deficiency. Copper deficiency enhances Zn uptake and then stimulates the biosynthesis of chlorophyll. This compensation effect may explain the normal chlorophyll content under Cu deficiency.更多还原