Mechanisms, Gene Targets and Response Strategies of Retrograde Signaling During Mitochondrial Perturbations in Plants

线粒体是执行许多新陈代谢过程并产生必要化学能量的亚细胞隔间。高臭氧水平和寒冷等环境压力会对植物线粒体功能产生负面影响，从而限制生产力。有证据表明，线粒体是“传感器”，它将细胞状态的变化传递给细胞核，从而改变基因的表达；这个过程被称为线粒体逆行调节(MRR)。据推测，基因表达的变化是为了从压力造成的干扰中恢复过来。这是一个重要的研究领域，因为越来越清楚的是，MRR是许多真核生物应激和疾病反应的一个基本方面。然而，这种线粒体到细胞核的通讯机制仍然难以捉摸。这项研究的结果将使人们更好地了解线粒体如何与细胞核通信以改变基因的活动。这将通过1)生物化学和代谢组学来识别可能参与MRR的化合物；2)“反向遗传学”来研究缺乏被认为参与MRR的特定蛋白质的植物；以及3)基因组学来识别模式植物拟南芥中所有在MRR反应的早期阶段受到影响的基因。预计这项研究工作将导致鉴定MRR分子机制的组成部分，以及植物用来克服环境胁迫的线粒体导向策略。如果能够提高MRR，这一进步可能会使作物生产出更耐受环境压力的作物，并提高粮食和生物燃料的植物生产率。该项目将涉及研究生、本科生和博士后研究员。此外，它将是高中教师培训计划的一部分，并为学生(包括科学方面代表性不足的群体的成员)提供机会，将其作为高中课程的一部分参与生物技术/基因组研究。

Mitochondria are the sub-cellular compartments that perform numerous metabolic processes and produce necessary chemical energy. Environmental stresses such as high ozone levels and cold can negatively affect plant mitochondrial function, which can limit productivity. Evidence suggests that mitochondria are 'sensors' that communicate cell status changes to the nucleus to alter expression of genes; a process called mitochondrial retrograde regulation (MRR). Presumably, the changes in gene expression are directed at recovering from the perturbations caused by the stresses. This is an important research area because it is becoming increasingly clear that MRR is a fundamental aspect of many eukaryotic stress and disease responses. However, the mechanisms of this mitochondria-to-nucleus communication remain elusive. Results from this research will allow a greater understanding of how mitochondria can communicate with the nucleus to alter the activity of genes. This will be accomplished by using 1) biochemistry and metabolomics to identify compounds that may be involved in MRR; 2) "reverse genetics" to study plants that lack specific proteins thought to be involved in MRR; and 3) genomics to identify all genes in the model plant Arabidopsis thaliana that are affected in the early stages of the MRR response. It is expected that this research effort will result in identification of components of the molecular mechanisms of MRR and mitochondria-directed strategies that plants use to overcome environmental stresses. If MRR can be enhanced, this advance may allow production of crop plants that are more tolerant to environmental stresses and increased plant productivity for food and biofuels. This project will involve graduate students, undergraduate students and post-doctoral fellows. Additionally, it will be part of a training program for high school teachers and provide opportunities for students (including members of under-represented groups in science) to participate in biotechnology/genomic research as part of a high school curriculum.