期刊
PHYSIOLOGIA PLANTARUM
卷 128, 期 1, 页码 186-197出版社
WILEY
DOI: 10.1111/j.1399-3054.2006.00720.x
关键词
-
We conducted a series of experiments to assess the effects of oxidative stress on chlorophyll biosynthesis in the vascular plant Cucumis sativus (cucumber). Specifically, cucumber cotyledons were treated with 100 mu M methyl viologen (MV) and subsequently exposed to dark (0 mu E m(-2) s(-1)), low light (4045 mu E m(-2) s(-1)), or high light (1500-1600 mu E m(-2) s(-1)). Following treatment, extracts of these samples were subjected to high-performance liquid chromatography (HPLC) to quantitate the accumulation of chlorophyll biosynthetic pathway intermediates. The results of these analyses revealed significant accumulation of Mg-protoporphyrin IX monomethyl ester (Mg-proto IX ME) in green (14-h illuminated) as well as in etiolated cotyledons with MV treatment. These data suggest that MV-induced oxidative stress may have inhibited Mg-proto IX ME cyclase activity. Upon exposure to high light, in the presence or absence of MV, both green and etiolated cotyledons predominantly accumulated protoporphyrin IX (Proto IX). These elevated levels of Proto IX might be attributable to attenuated activity of any or all of the following enzymes: Mg-chelatase, Fe-chelatase and protoporphyrinogen IX oxidase. We also observed that MV-induced oxidative stress impacts on chlorophyll biosynthesis to a greater extent than on photosystem II. These results demonstrate that oxidative stress impedes key steps in chlorophyll biosynthesis by either directly or indirectly inhibiting the activity of these enzymes.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据