Engineering of ubiquinone biosynthesis using the yeast coq2 gene confers oxidative stress tolerance in transgenic tobacco
Engineering of ubiquinone biosynthesis using the yeast coq2 gene confers oxidative stress tolerance in transgenic tobacco
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DOI：
10.1111/j.1365-313x.2004.02246.x
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发表时间：
2004-12-01
期刊：
影响因子：
7.2
通讯作者：
Yazaki, K
中科院分区：
文献类型：
--
作者：
Ohara, K;Kokado, Y;Yazaki, K
泛醌（UQ）是从细菌到人类呼吸链中的电子载体，在体外具有抗氧化活性，但其在植物体内的生理作用尚不清楚。通过过表达酵母基因coq 2（其编码对羟基苯甲酸：聚异戊二烯基转移酶）来修饰UQ生物合成，以增加UQ-6在酵母中的积累和UQ-10在烟草中的积累。酵母和烟草转基因株系的UQ分别增加了约3倍和6倍。COQ 2多肽，其定位被强制改变到内质网，在酵母和烟草转化体中对UQ的增加具有与ESTA定位的COQ 2相同或更大的作用，表明UQ中间体从内质网转运到线粒体。具有高UQ水平的植物对甲基紫精或高盐度引起的氧化胁迫具有更强的抗性。这是由于与野生型相比，转基因株系具有更强的自由基清除能力。
Ubiquinone (UQ), an electron carrier in the respiratory chain ranging from bacteria to humans, shows antioxidative activity in vitro, but its physiological role in vivo is not yet clarified in plants. UQ biosynthesis was modified by overexpressing the yeast gene coq2, which encodes p-hydroxybenzoate:polyprenyltransferase, to increase the accumulation of UQ-6 in yeast and UQ-10 in tobacco. The yeast and tobacco transgenic lines showed about a three- and six-fold increase in UQ, respectively. COQ2 polypeptide, the localization of which was forcibly altered to the endoplasmic reticulum, had the same or a greater effect as mitochondria-localized COQ2 on the increase in UQ in both the yeast and tobacco transformants, indicating that the UQ intermediate is transported from the endoplasmic reticulum to the mitochondria. Plants with a high UQ level are more resistant to oxidative stresses caused by methyl viologen or high salinity. This is attributable to the greater radical scavenging ability of the transgenic lines when compared with the wild type.