Plant mitochondrial gene expression and evolution

植物线粒体基因表达和进化

• 批准号: 46530-2011
• 负责人: Bonen, Linda
• 金额: $ 2.91万
• 依托单位: University of Ottawa
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2015
• 资助国家: 加拿大
• 起止时间: 2015-01-01 至 2016-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=568975
• 关键词: Plant; mitochondrial; gene; expression; evolution

Mitochondria possess their own distinctive DNA, with genes essential for cellular energy production. Since the time that mitochondria arose through symbiosis between a primitive respiring bacterium and host cell, they have evolved very different ways of storing and decoding genetic information. The study of mitochondria from plants, animals, fungi and protists has uncovered a wealth of novel features (such as altered genetic codes, RNA editing, mobile intron ribozymes), and this has prompted a reconsideration of certain fundamental principles in molecular biology. My research program focuses on the mitochondrial genetic systems of flowering plants, which have the largest and most dynamic mitochondrial DNAs known. RNA copied from their genes must undergo complex events (such as editing and trans-splicing) before being decoded into protein. The removal of introns, which belong to an intriguing family of self-splicing mobile retroelements, involves unusual splicing reactions, and we are using molecular, biochemical and bioinformatics strategies to understand mechanistic and evolutionary pathways taken. We are also studying RNA processing events during embryo-to-seedling development (under ambient and cold growth) in wheat, an important Canadian crop plant, and have particular interest in the impact of DNA rearrangements on expression. In some cases, scattered pieces of genes are still functional because RNA copies are correctly spliced together, whereas in other cases, DNA rearrangements are known to lead to mutants which are male sterile. The latter are important to crop breeders in the production of hybrid seed. Plants also offer a unique opportunity to study the successful movement of genes from the mitochondrion to the nucleus during evolution, because these events are still going on in plants. As we trace the steps involved in such migration, we are finding duplicated genes, silent genes, and pseudogenes. This work is directed at providing insight into how the different genetic compartments inside the plant cell communicate with each other, as well as how (genetically-manipulated) products can be targeted to the mitochondrion.

线粒体拥有自己独特的DNA，以及细胞能量产生所必需的基因。自从线粒体通过原始呼吸细菌和宿主细胞之间的共生而出现以来，它们已经进化出非常不同的存储和解码遗传信息的方式。对植物、动物、真菌和原生生物的线粒体的研究揭示了大量新的特征（如改变的遗传密码、RNA编辑、移动的内含子核酶），这促使人们重新思考分子生物学的某些基本原则。 我的研究项目主要集中在开花植物的线粒体遗传系统，它具有已知的最大和最动态的线粒体DNA。从它们的基因复制的RNA在被解码成蛋白质之前必须经历复杂的事件（如编辑和反式剪接）。内含子，这属于一个有趣的家庭自我剪接移动的逆转录元件，涉及不寻常的剪接反应，我们正在使用分子，生物化学和生物信息学策略，以了解机制和进化途径。我们还研究RNA加工过程中的事件胚胎到幼苗的发展（在环境和寒冷的生长）在小麦，一个重要的加拿大作物植物，并有特别的兴趣在DNA重排的影响表达。在某些情况下，分散的基因片段仍然有功能，因为RNA拷贝正确地拼接在一起，而在其他情况下，DNA重排已知会导致雄性不育的突变体。后者对作物育种者生产杂交种子很重要。 植物也提供了一个独特的机会来研究基因在进化过程中从细胞核到细胞核的成功运动，因为这些事件仍然在植物中进行。当我们追踪这种迁移所涉及的步骤时，我们发现了复制基因、沉默基因和假基因。这项工作旨在深入了解植物细胞内不同的遗传区室如何相互交流，以及如何（遗传操纵）产品可以靶向细胞。