TARGETING THE MAIZE T-URF13 PRODUCT INTO TOBACCO MITOCHONDRIA CONFERS METHOMYL SENSITIVITY TO MITOCHONDRIAL RESPIRATION
TARGETING THE MAIZE T-URF13 PRODUCT INTO TOBACCO MITOCHONDRIA CONFERS METHOMYL SENSITIVITY TO MITOCHONDRIAL RESPIRATION
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DOI：
10.1073/pnas.92.4.1167
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发表时间：
1995-02-14
影响因子：
11.1
通讯作者：
BOUTRY, M
中科院分区：
文献类型：
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作者：
CHAUMONT, F;BERNIER, B;BOUTRY, M
玉米线粒体T-urf 13基因编码的URF 13蛋白被认为是致病毒素和灭多威敏感性以及雄性不育的原因。我们研究了T-urf 13在其他植物中表达时是否赋予毒素敏感性和雄性不育性。将T-urf 13编码序列与线粒体靶向前序列融合，置于花椰菜花叶病毒35 S启动子的控制下，并通过根癌农杆菌介导的转化导入烟草。亚细胞分析表明，URF 13主要与线粒体结合，在线粒体中加入灭多威后，线粒体的呼吸和氧化磷酸化反应均增强，说明URF 13被导入线粒体，并赋予了灭多威对毒素的敏感性。大多数表达缺乏线粒体前序列的T-urf 13构建体的对照植物是灭多威敏感的，并且在膜部分中含有URF 13。通过蔗糖梯度离心的亚细胞分级显示URF 13沉淀在几个位置，表明该蛋白质与包括线粒体在内的各种细胞器相关。表明URF 13不是输入的，并且不赋予线粒体毒素敏感性。因此，URF 13赋予转基因烟草毒素敏感性，无论是否输入线粒体。URF 13的表达与雄性不育性之间没有相关性，表明URF 13在转基因烟草中不引起雄性不育，或者URF 13在适当的花药细胞中没有以足够的量表达。
The URF13 protein, which is encoded by the maize mitochondrial T-urf13 gene, is thought to be responsible for pathotoxin and methomyl sensitivity and male sterility, We have investigated whether T-urf13 confers toxin sensitivity and male sterility when expressed in another plant species, The coding sequence of T-urf13 was fused to a mitochondrial targeting presequence, placed under the control of the cauliflower mosaic virus 35S promoter, and introduced into tobacco by Agrobacterium tumefaciens-mediated transformation. Plants expressing high levels of URF13 were methomyl sensitive, Subcellular analysis indicated that URF13 is mainly associated with the mitochondria, Adding methomyl to isolated mitochondria stimulated NADH-linked respiration and uncoupled oxidative phosphorylation, indicating that URF13 was imported into the mitochondria, and conferred toxin sensitivity. Most control plants, which expressed the T-urf13 construct lacking the mitochondrial presequence, were methomyl sensitive and contained URF13 in a membrane fraction, Subcellular fractionation by sucrose gradient centrifugation showed that URF13 sedimented at several positions, suggesting the protein is associated with various organelles, including mitochondria, No methomyl effect was observed in isolated mitochondria, however, indicating that URF13 was not imported and did not confer toxin sensitivity to the mitochondria. Thus, URF13 confers toxin sensitivity to transgenic tobacco with or without import into the mitochondria, There was no correlation between the expression of URF13 and male sterility, suggesting either that URF13 does not cause male sterility in transgenic tobacco or that URF13 is not expressed in sufficient amounts in the appropriate anther cells.