CAREER: Temporal and Transgenerational Genomic and Epigenetic Effects of Hybridization in Long-generation Tree Species

该奖项全部或部分由2021年美国救援计划法案（公法117-2）资助。变暖的气温和更严重、更频繁的高温事件将给商业植物物种的发展和生存带来重大挑战。因此，深入了解表型可塑性反应和耐旱性对于物种管理至关重要。对于像道格拉斯冷杉这样世代较长的树种，今天所采取的管理决策将影响到今后50-100年森林的生产力。这项研究的成果将是第一个针叶树种，并将显着有助于我们了解的基因组和表观基因组的基础上的表型变异在长世代树种。杂交在道格拉斯冷杉和其他针叶树适应气候变化中的作用研究得很少，因此这项研究也将对该领域做出重要贡献。本科生和研究生将通过实习、课程模块和暑期研讨会接受分子实验室技术、温室工作和生物信息学分析方面的培训。将通过K-12学校的科学博览会和公共科学活动鼓励非正式科学教育。了解表型变异的基因组和表观基因组基础是一个关键的生物学问题。环境胁迫和杂交可以产生广泛的基因组和表观基因组变化，这些变化可以传递给后代，并可能有助于植物在可变环境中持续存在的能力。本项目将调查杂交对时间和遗传基因组和表观基因组变化的贡献，这些变化可能导致经济上重要的木材物种道格拉斯冷杉（DF，花旗松变种）的两个品种的生长和耐旱性增加。glauca和var.menziessii）。变暖的温度和更频繁的热事件将降低商业DF沿海品种的生长能力，这是耐旱性较低。相比之下，DF内部品种更耐旱，但生长缓慢，因此不适合商业用途。初步研究表明，品种间杂种比亲本表现出更强的耐旱性，这可能是由于超亲分离或适应性渐渗所致。本研究结合了该物种纯合品种、F1、F2代和高世代杂种的生理研究、基因组、表观基因组和表达数据，从基因组和表观基因组上研究杂交的跨代效应，剖析杂种优势和超亲分离的分子基础。在开展这些研究工作的同时，本项目旨在培养一名博士后研究员和31名本科生和研究生。包括数据和教育资源在内的项目成果将通过项目/实验室网站以及TreeGenes和其他长期公共数据库公开获取。该奖项反映了NSF的法定使命，并被认为值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估来支持。

This award is funded in whole or in part under the American Rescue Plan Act of 2021 (Public Law 117-2).Warming temperatures and more severe and frequent heat events will bring significant challenges to the development and survival of commercial plant species. Therefore, a deep understanding of the phenotypic plastic responses and drought tolerance is crucial for species management. In long-generation tree species, such as Douglas fir, the management decisions taken today will affect the productivity of forests over the next 50-100 years. The outcomes of this research will be the first of their kind for a conifer species and will significantly contribute to our understanding of the genomic and epigenomic basis of phenotypic variation in long-generation tree species. The role of hybridization in adaptation to changing climates in Douglas fir and other conifers has been poorly studied, so this study will also make important contributions to that area. Undergraduate and graduate students will be trained in molecular lab techniques, greenhouse work and bioinformatic analyses through internships, course modules and summer workshops. Informal science education will be encouraged through science expositions at K-12 schools and public scientific events. Understanding the genomic and epigenomic basis of phenotypic variation is a key biological question. Environmental stresses and hybridization may produce wide genomic and epigenomic changes that can be transmitted to subsequent generations and may contribute to the ability of plants to persist in variable environments. This project will investigate the contribution of hybridization to temporal and inheritable genomic and epigenomic changes that could lead to increased growth and drought tolerance in two varieties of the economically important timber species Douglas fir (DF, Pseudotsuga menziessii var. glauca and var.menziessii). Warming temperatures and more frequent heat events will reduce the growth capacity of the commercial DF coastal variety which is less drought tolerant. In contrast, the DF interior variety is more drought-tolerant, but grows slowly, and is therefore not ideal for commercial purposes. Preliminary studies suggest hybrids between varieties show increased drought tolerance than its parents, which could be due to transgressive segregation or adaptive introgression. This study combines physiological studies, genomic, epigenomic and expression data of pure varieties, F1s, F2s and advanced-generation hybrids in the species, allowing the study of transgenerational effects of hybridization in the genome and epigenome, and the dissection of the molecular basis of heterosis and transgressive segregation. Simultaneous with these research efforts, this project aims to train one postdoctoral fellow, and 31 undergraduate and graduate students. Project outcomes including data and educational resources will be made publicly accessible through project/lab websites as well as through TreeGenes and other long-term public data repositories.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.