Polycomb Response Elements (PREs) and Polycomb Recruitment in Plants

植物中的 Polycomb 响应元件 (PRE) 和 Polycomb 募集

• 批准号: 1243757
• 负责人: Doris Wagner
• 金额: $ 75.02万
• 依托单位: University of Pennsylvania
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-03-15 至 2017-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1243757&HistoricalAwards=false
• 关键词: Polycomb; Response; Elements; PREs; Recruitment

Intellectual Merit: In eukaryotes, genomic DNA is highly compacted in the nucleus. This compaction renders portions of the genomic DNA inaccessible to transcription factors or the general transcriptional machinery. A large fraction of the inaccessible DNA consists of gene-poor heterochromatin. Portions of the gene-rich euchromatin are also inaccessible or silenced. A hallmark of this silencing is that it occurs only in certain conditions, for example in some cell types or in the absence of an environmental cue. In multicellular eukaryotes, euchromatic silencing is largely mediated by Polycomb repression. Polycomb repressors do not have inherent sequence specificity; instead, they need to be targeted to the correct genomic loci. This project will identify DNA sequence motifs that direct Polycomb repressors to euchromatic genomic regions in Arabidopsis thaliana for proper plant development and proper plant stress responses. The ultimate goal of the project is to be able to predict--based on the presence of the DNA sequence motifs--which genomic regions Polycomb repressors can be recruited to in this, and in other, plant species and to identify the sequence-specific binding factors involved in the recruitment. Broader Impacts: The project will train the next generation of scientists in state-of the art research. Undergraduate researchers, including underrepresented minorities, will conduct individual independent laboratory research and conduct research in new one-semester-long lab modules. The research will be related to the main objectives of the project. In the past, the undergraduate contributions have been excellent and have warranted authorships on scientific publications. The project will teach topics related to chromatin-mediated regulation of genome accessibility to high-school students in a summer course and to Biology teachers of inner city high schools during professional development sessions. Finally, the project will train researchers from other labs and institutions in critical techniques used in this field. In plants, Polycomb repression regulates the transition to reproductive development, flower formation and seed development as well as response to abiotic stress. Understanding and consequently being able to manipulate the recruitment of these activities to certain regions in the plant DNA should thus allow improvement of agricultural traits such as biomass and seed production as well as water stress tolerance.

智力优势：在真核生物中，基因组DNA在细胞核中高度致密。这种紧凑使基因组DNA的一部分无法被转录因子或一般转录机制所访问。很大一部分无法接触到的DNA由缺乏基因的异染色质组成。富含基因的常染色质的部分也是无法访问或沉默的。这种沉默的一个特点是，它只在特定的条件下发生，例如在某些细胞类型中或在没有环境提示的情况下。在多细胞真核生物中，常染色质沉默在很大程度上是由Polycomb抑制所介导的。多梳抑制物不具有固有的序列特异性；相反，它们需要针对正确的基因组位点。这个项目将确定DNA序列基序，这些基序将多梳阻遏物定向到拟南芥的常染色质基因组区域，以实现适当的植物发育和适当的植物胁迫反应。该项目的最终目标是能够--基于DNA序列基序的存在--预测这种植物和其他植物物种中Polycomb阻遏物可以招募到哪些基因组区域，并确定招募过程中涉及的序列特异性结合因素。更广泛的影响：该项目将培训下一代科学家进行最先进的研究。本科生研究人员，包括未被充分代表的少数民族，将进行个人独立实验室研究，并在为期一学期的新实验模块中进行研究。这项研究将与项目的主要目标有关。过去，本科生的贡献一直很出色，因此有资格在科学出版物上发表论文。该项目将在暑期课程中向高中生传授与染色质介导的基因组可及性调节相关的主题，并在专业发展课程中向市中心高中的生物学教师传授相关主题。最后，该项目将对其他实验室和机构的研究人员进行该领域使用的关键技术方面的培训。在植物中，多梳抑制调控向生殖发育、花形成和种子发育的过渡以及对非生物胁迫的反应。因此，了解并因此能够操纵这些活动在植物DNA中的某些区域的招募，应该能够改善诸如生物量和种子生产等农业特性以及对水分胁迫的耐受性。