Intersection of the Plant Epigenome and Bioenergetics in Phenotypy

S.麦肯齐，PI，内布拉斯加大学M。弗洛姆，coPI，内布拉斯加大学。Yu，coPI，内布拉斯加大学A.劳伦斯，首席信息官，内布拉斯加大学。王，合作者，内布拉斯加大学J.-内布拉斯加大学的合作者J. Rimeirs线粒体和叶绿体是细胞的生物能量焦点，划分了细胞功能的代谢基础。同样，它们作为关键的环境压力传感器，对处理植物防御反应至关重要。 然而，它们整合到植物细胞的系统模型中，由于无法以足够的特异性干扰它们的功能而变得复杂。 该研究团队实施了一种优雅的方法来改变线粒体和叶绿体的特性，重点是操纵单个核基因MSH 1（MutS同源物1）。 MSH 1功能的丧失产生细胞器变化，以调节不同的植物生长表型，而不改变植物的基因型。 这些变化包括生长速率、开花时间、繁殖、叶绿体发育以及生物和非生物胁迫反应的急剧变化。 作为本研究的中心假设，假定与msh 1相关的细胞器改变引起植物表观基因组的可遗传的、程序化的变化。 计划中的调查利用最近的关键观察涉及MSH 1，并实施跨物种的比较分析，在转录本配置文件为基础的解剖出现的表型。 该项目测试msh 1对小RNA和DNA甲基化变化的影响，使用拟南芥作为未来在高粱和大豆中测试的初始模型。 该合作结合了细胞器生物学，定量遗传学，表观遗传学和下一代序列技术的专业知识，以研究细胞器信号对植物表观基因组的影响。 这些研究解决了生物学中关于压力信号的跨代传递模式和细胞器作为植物细胞压力传感组件的作用的主要未回答的问题。 自达尔文时代以来，遗传学家就一直在推测杂种优势和跨代适应压力的潜在基础。 虽然最近的证据表明这些现象具有表观遗传性质，但直接调查将生物能量或环境传感与细胞中的表观遗传程序联系起来的过程通常是棘手的。 我们调查的系统可能在解决这些过程中证明是无价的。 因此，这项研究可能对植物育种过程以及我们对植物防御和适应的理解具有重要意义。 这些研究将把高中和本科生纳入暑期研究活动，作为我们鼓励科学研究事业的计划的一部分。

S. Mackenzie, PI, University of NebraskaM. Fromm, coPI, University of NebraskaB. Yu, coPI, University of NebraskaA. Lorenz, coPI, University of NebraskaD. Wang, collaborator, University of NebraskaJ.-J. Riethoven, collaborator, University of NebraskaMitochondria and chloroplasts serve as bioenergetic focal points of the cell, compartmenting the metabolic underpinnings of cellular function. Likewise, they act as key environmental stress sensors, and are vital to processing plant defense responses. Yet, their integration to a systems model for the plant cell has been complicated by inability to perturb their functions with adequate specificity. This research team has implemented an elegant approach to alter mitochondrial and chloroplast properties that focuses on manipulation of a single nuclear gene, MSH1 (MutS homolog 1). Loss of MSH1 function produces organelle changes to condition distinct plant growth phenotypes without altering genotype of the plant. These include dramatic changes in growth rate, flowering time, reproduction, chloroplast development, and biotic and abiotic stress responses. it is postulated, as the central hypothesis to this research, that the msh1-associated organelle alterations cause heritable, programmed changes to the plant epigenome. The planned investigations capitalize on recent key observations involving MSH1, and implement cross-species comparative analysis in transcript profile-based dissection of emergent phenotypes. The project tests for msh1 effects on small RNA and DNA methylation changes, using Arabidopsis as an initial model for future tests in sorghum and soybean. The collaboration combines expertise in organelle biology, quantitative genetics, epigenetics and next-gen sequence technologies to investigate the influence of organelle signals on the plant epigenome. These studies address major unanswered questions in biology regarding the mode of trans-generational transmission of stress signals and the role of organelles as stress sensing components of the plant cell.Broader impacts. Since Darwin's time, geneticists have speculated about the underlying basis of hybrid vigor and trans-generational adaptations to stress. While more recent evidence has suggested an epigenetic nature to these phenomena, direct investigation of the process linking bioenergetic or environmental sensing with epigenetic programs in the cell has generally been intractable. The system we investigate may prove invaluable in addressing these processes. Consequently, this research could have important implications for the plant breeding process and for our understanding of plant defense and adaptation. These studies will incorporate high school and undergraduate students in summer research activities, as part of our program to encourage careers in science research.