期刊
NEW PHYTOLOGIST
卷 163, 期 3, 页码 585-594出版社
WILEY
DOI: 10.1111/j.1469-8137.2004.01132.x
关键词
UV-radiation; auxin; stress; peroxidase; chlorophyll a fluorescence; Nicotiana tabacum (tobacco)
Class III peroxidases catalyse the oxidative crosslinking of UV-absorbing phenolics. The effect of changes in the activity of phenol oxidising peroxidases (EC 1.11.1.7) on UV-tolerance in Nicotiana tabacum plants has been determined. The UV-sensitivity of transgenic N. tabacum lines, altered in their peroxidase expression pattern, was studied by measuring radiation effects on photosynthetic efficiency. Analysis of the effect of UV-radiation on the relative variable chlorophyll fluorescence showed that the SPI-2 line, which over-expresses a defence-related cationic peroxidase, is markedly UV-tolerant. By contrast, the ROPN3-line, which overexpresses a synthetic horseradish peroxidase-C gene, was found to be UV-sensitive. The increased activity of indole-3-acetic acid (IAA) inducible peroxidases in homozygous IAA-overproducing transgenic plants was also found to correlate with UV-sensitivity. It is concluded that only specific peroxidase isozymes, through their effects on phenolic metabolism, contribute to the UV protection response. Thus, the analysis of the role of isozymes in UV-protection addresses fundamental questions of isozyme diversity and/or redundancy in relation to phenolic substrates.
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