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

该奖项的全部或部分资金根据《2021 年美国救援计划法案》（公法 117-2）提供。气温变暖以及更加严重和频繁的高温事件将为商业植物物种的发育和生存带来重大挑战。因此，深入了解表型塑料反应和耐旱性对于物种管理至关重要。对于花旗松等长世代树种，今天采取的管理决策将影响未来 50-100 年的森林生产力。这项研究的结果将是针叶树物种中的首次研究成果，并将极大地有助于我们了解长世代树种表型变异的基因组和表观基因组基础。花旗松和其他针叶树杂交在适应气候变化方面的作用尚未得到充分研究，因此这项研究也将为该领域做出重要贡献。本科生和研究生将通过实习、课程模块和夏季研讨会接受分子实验室技术、温室工作和生物信息分析方面的培训。将通过 K-12 学校的科学展览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。环境胁迫和杂交可能会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多变的环境中生存的能力。该项目将研究杂交对时间和可遗传的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树种道格拉斯冷杉（DF、Pseudotsuga menziessii var. glauca 和 var.menziessii）的两个品种的生长和耐旱性增强。气温升高和更频繁的高温事件将降低耐旱性较差的商业 DF 沿海品种的生长能力。相比之下，DF内陆品种更耐旱，但生长缓慢，因此不适合商业用途。初步研究表明，品种之间的杂交表现出比其亲本更高的耐旱性，这可能是由于海侵隔离或适应性渗入所致。这项研究结合了物种中纯种、F1、F2和高代杂种的生理学研究、基因组、表观基因组和表达数据，可以研究基因组和表观基因组杂交的跨代效应，并剖析杂种优势和越界分离的分子基础。在开展这些研究工作的同时，该项目旨在培养一名博士后、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存储库向公众开放。该奖项反映了 NSF 的法定使命，并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，被认为值得支持。

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.