Genetics of Maize Mitochondria

玉米线粒体遗传学

• 批准号: 9406055
• 负责人: Kathleen Newton
• 金额: $ 43万
• 依托单位: University of Missouri-Columbia
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1994
• 资助国家: 美国
• 起止时间: 1994-09-01 至 1999-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9406055&HistoricalAwards=false
• 关键词: Genetics; Maize; Mitochondria

Abstract 9406055 A long-term objective of this project is to understand the effects of individual plant mitochondrial genes on organelle biogenesis and overall cellular function. The genetic analysis of plant mitochondrial genomes has been limited due to the fact that only a few mutations with known progenitors have been described. We have focused on a set of lethal maize mutations (Nonchromosomal stripe; NCS) that survive in heteroplasmic plants. Different NCS mutants are associated with distinct phenotypes and the mutations have been shown to be deletions affecting the expression of at least three different mitochondrial genes (cox2, nad4 and the co-transcribed S3 an L16 ribosomal protein genes. The major goal of the current proposal is to transform mitochondria that are homoplasmic for a deletion of the 5' end and promoter sequences of cytochrome oxidase subunit 2 with a distinguishable, functional copy of cox2. This would open up higher plant mitochondria to genetic manipulations that cannot otherwise be performed. Normal and mutant promoter constructs will be tested in vivo. We propose to continue our analyses of new mitochondrial mutations, particularly the partially characterized NCS4 mutation. The NCS4 mutant rearrangement involves S2-plasmid sequences that have incorporated into the mitochondrial genome. Finally, we propose to continue our genetic approach to analyzing the roles of mitochondria during plant development. The mutants in different steps of oxidative phosphorylation have distinguishable effects on chlorophyll levels and the production of nuclear-coded products for chloroplast function. We will also use the mutants to determine when mitochondrial function is essential for the survival of cells, tissues and organs. %%% The long-term objective of this project is to understand the effects of individual plant mitochondrial genes on organelle biogenesis and overall cellular function. During the tenure of this award, the focus will be on: (1) devel oping procedures for transforming higher plant mitochondria (2) continuing the analysis of existing mitochondrial mutations and (3) continuing to genetically analyze the role(s) of mitochondria during plant development. ***

摘要9406055本项目的一个长期目标是了解单个植物线粒体基因对细胞器生物发生和整体细胞功能的影响。植物线粒体基因组的遗传分析一直受到限制，因为只有少数突变与已知的祖先已被描述。我们已经集中在一组致命的玉米突变（非染色体条纹; NCS），在异质性植物中生存。不同的NCS突变体与不同的表型相关，并且突变已显示为影响至少三种不同线粒体基因（cox 2、nad 4和共转录的S3和L16核糖体蛋白基因）表达的缺失。目前的建议的主要目标是转化同质的线粒体，用于删除细胞色素氧化酶亚基2的5'端和启动子序列，并具有可区分的cox 2的功能性拷贝。这将打开高等植物线粒体的基因操作，否则不能执行。将在体内测试正常和突变启动子构建体。我们建议继续分析新的线粒体突变，特别是部分表征的NCS 4突变。NCS 4突变体重排涉及已并入线粒体基因组的S2质粒序列。最后，我们建议继续我们的遗传方法来分析线粒体在植物发育过程中的作用。在氧化磷酸化的不同步骤中的突变体对叶绿素水平和叶绿体功能的核编码产物的产生具有可区分的影响。我们还将使用突变体来确定线粒体功能何时对细胞，组织和器官的生存至关重要。 本项目的长期目标是了解单个植物线粒体基因对细胞器生物发生和整体细胞功能的影响。 在该奖项的任期内，重点将放在：（1）开发转化高等植物线粒体的程序（2）继续分析现有的线粒体突变和（3）继续遗传分析线粒体在植物发育过程中的作用。 ***