TRMS: An Integrative Study of Plant Mitochondrial Biology

Pi：Sally Mackenzie(内布拉斯加州大学)Copis：Alan Christensen(内布拉斯加州大学)，Tom Elthon(内布拉斯加州大学)，Don Wang(内布拉斯加州大学)合作者：Andrew Benson(内布拉斯加州大学)植物线粒体基因组在结构和维护特性上经历了许多变化，使其有别于哺乳动物。到目前为止，大多数植物基因组都是线性和环状相互转换分子的复杂集合，显示出重组、外源DNA整合和相对拷贝数变化的证据。这些基因组活动是由核基因控制的，核基因可以在表达过程中受到操纵，从而导致线粒体基因组的不稳定。在番茄、烟草、谷子、高粱、大豆和拟南芥中使用这种方法，可以进行线粒体基因组破坏的跨物种比较。这个项目利用这个系统来识别直接受线粒体基因组状态影响的细胞和发育途径，这些途径在植物物种中是保守的，并被植物表型的变化所证明。该项目的中心假设是，植物中的线粒体状态被整合到叶绿体发育、花粉发育、细胞周期控制和特定的植物逆境反应的离散途径中。该项目通过将拟南芥突变分析和跨物种比较与线粒体和基因表达分析相结合，提供了进入这些途径集成点的独特入口。虽然很早就知道植物线粒体在新陈代谢、生长和发育中发挥着不同的作用，但在本研究之前，直接的线粒体操作在很大程度上仅限于抑制剂研究，推断整个植物表型的机会有限。这项研究的更广泛的影响。植物线粒体基因组重排可以导致植物表型的改变，具有重要的农业意义。例如，这些研究已经产生了细胞质雄性不育的证据，这是一种在杂交种子生产和转基因遏制方面有用的特征，以及提高了作物的耐热性。这两个有价值的性状都很难用传统的作物育种方法获得。关于培训机会，内布拉斯加州大学植物科学创新中心(PSI)赞助了一项本科暑期实习计划，该计划纳入了拟议的项目；通过该计划，过去两年已经有四名少数族裔学生被招募到研究生计划中。PSI还指导了内布拉斯加州分子植物育种研究生计划；该项目至少资助了两名植物育种专业的学生参与拟议的项目。目前，美国面临着在转基因作物的田间管理、基于DNA标记的选择、统计和比较基因组学方面具有交叉专业知识的植物育种者的严重短缺。该项目与校园和工业中的植物育种者合作，为此类培训提供了肥沃的土壤。项目数据将通过http://psiweb.unl.edu/mackenzie/和发布到ArrayExpress(http://www.ebi.ac.uk/microarray-as/ae/).)的基因表达数据来访问

PI: Sally Mackenzie (University of Nebraska) CoPIs: Alan Christensen (University of Nebraska), Tom Elthon (University of Nebraska), Dong Wang (University of Nebraska) Collaborator: Andrew Benson (University of Nebraska)Plant mitochondrial genomes have undergone a number of changes in their structure and maintenance properties that distinguish them from their mammalian counterparts. Most plant genomes characterized to date are a complex collection of linear and circular interconverting molecules that display evidence of recombination, foreign DNA integration and changes in relative copy number. These genomic activities are controlled by nuclear genes that can be manipulated in their expression to cause mitochondrial genome instability. Using this approach in tomato, tobacco, millet, sorghum, soybean and Arabidopsis allows for cross-species comparison of mitochondrial genome disruption. This project exploits this system to identify cellular and developmental pathways that are directly influenced by mitochondrial genome status, conserved across plant species, and evidenced by changes in plant phenotypes. The central hypothesis of the project states that mitochondrial status in plants is integrated into discrete pathways for plastid development, pollen development, cell cycle control and particular plant stress responses. The project provides unique entry to these pathway integration points by combining Arabidopsis mutant analysis and cross-species comparisons with mitochondrial and gene expression analysis. While it has long been known that plant mitochondria play distinct roles in metabolism, growth and development, direct mitochondrial manipulations prior to this study were largely restricted to inhibitor studies with limited opportunity for extrapolation to whole plant phenotype. Broader impacts of the study. Plant mitochondrial genome rearrangement can lead to altered plant phenotypes of agricultural importance. For example, these studies have already produced evidence of cytoplasmic male sterility, a trait useful in hybrid seed production and transgene containment, and of enhanced crop thermotolerance. Both valuable traits are difficult to attain using conventional crop breeding approaches. With regard to training opportunities, the Center for Plant Science Innovation (PSI) at University of Nebraska sponsors an undergraduate summer internship program that integrates to the proposed project; through this program, four minority students have already been recruited into graduate programs in the past two years. The PSI also directs the Nebraska Molecular Plant Breeding Graduate Program; this project sponsors at least two plant breeding students on the proposed project. Currently, the US faces a critical shortage of plant breeders with cross-cutting expertise in field management of transgenic crops, DNA marker-based selection, statistics, and comparative genomics. This project provides fertile ground for such training, in cooperation with plant breeders on campus and in industry.Project data will be accessible via http://psiweb.unl.edu/mackenzie/ and gene expression data released to ArrayExpress (http://www.ebi.ac.uk/microarray-as/ae/).