The evolution of herbicide resistance

除草剂抗性的演变

• 批准号: RGPIN-2020-06276
• 负责人: Yakimowski, Sarah
• 金额: $ 2.04万
• 依托单位: Queen's University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=745955
• 关键词: evolution; herbicide; resistance

Rapid contemporary evolution is an opportunity to investigate the dynamics of evolution in response to environmental stress. Gene copy number variation, a common but understudied form of genetic variation, has emerged as a mechanism that can play a role in adaptation to environmental stress, including the evolution of herbicide resistance in plants. The origin(s) of copy number variation, its relationship to resistance phenotype, and the upper limit(s) to copy number are not well understood in plants. Moreover, the potential interaction between a gene copy number variant and genomic background is acknowledged but rarely investigated, especially across a geographic range. Therefore, to advance understanding of gene copy number evolution I propose a quantitative genetic approach. I will use the evolution of resistance to the ubiquitous herbicide, glyphosate, in Amaranthus palmeri as a model to explore the evolutionary limit(s) of gene copy number. Copy number of resistance gene EPSPS (5enolpyruvyl- shikimate-3-phosphate synthase) ranges from 1 to >100 in A. palmeri. This crop weed is expanding its previously restricted range - southwest US and Mexico - now occurring across the US and moving toward the Canadian border. My long-term research goals will advance understanding of the role of copy number variation in evolution: What are the genetic mechanisms, evolutionary origin(s) and evolutionary limit(s) of stress resistance traits? How common is gene copy number variation, and how often is it involved in adaptation to the environment? The short-term research proposed here investigates whether EPSPS copy number variation explains the majority of variation in glyphosate resistance across the geographic range, and whether other genomic variation contributes. Historical plant samples provide opportunity to investigate whether EPSPS copy number variation pre-dated the development and ubiquitous use of glyphosate. To forecast the future trajectory of EPSPS copy number variation, we will extend EPSPS copy number variation through artificial selection in search of the upper limit(s) of gene copy number. This program is a rare opportunity to combine investigation of the historical, contemporary and future evolution of a trait in response to environmental change. The proposed research program at the intersection of evolutionary biology and agriculture provides training opportunities for 3 PhD, 4 MSc and 10 BSc HQP. For development of sustainable agriculture practices it is critical to understand the role herbicides play(ed) in the evolution of agricultural weed populations, and whether resistance evolution has potential to intensify, or has reached a stable limit. This program will train HQP in field biology, experimental design, quantitative genetics, statistics, genomics and bioinformatics, as well as both oral and written communication - preparing HQP for academic, industrial and/or government research.

当代快速进化是研究响应环境压力的进化动态的一个机会。基因拷贝数变异是一种常见但尚未得到充分研究的遗传变异形式，它已成为一种在适应环境压力（包括植物除草剂抗性进化）中发挥作用的机制。植物中拷贝数变异的起源、其与抗性表型的关系以及拷贝数的上限尚不清楚。此外，基因拷贝数变异与基因组背景之间的潜在相互作用已被承认，但很少进行研究，尤其是在地理范围内。因此，为了加深对基因拷贝数进化的理解，我提出了一种定量遗传方法。我将利用苋对普遍存在的除草剂草甘膦的抗性进化作为模型来探索基因拷贝数的进化极限。棕榈曲霉中抗性基因 EPSPS（5 烯醇丙酮酰莽草酸 3-磷酸合酶）的拷贝数范围为 1 至 >100。这种农作物杂草正在扩大其先前限制的范围 - 美国西南部和墨西哥 - 现在已经遍布美国并向加拿大边境移动。 我的长期研究目标将促进对拷贝数变异在进化中的作用的理解：抗逆性状的遗传机制、进化起源和进化极限是什么？基因拷贝数变异有多常见？它与环境适应有关的频率如何？这里提出的短期研究调查了 EPSPS 拷贝数变异是否解释了整个地理范围内草甘膦抗性的大部分变异，以及其他基因组变异是否有所贡献。历史植物样本提供了研究 EPSPS 拷贝数变异是否早于草甘膦的开发和普遍使用的机会。为了预测 EPSPS 拷贝数变异的未来轨迹，我们将通过人工选择来扩展 EPSPS 拷贝数变异，以寻找基因拷贝数的上限。该项目是一个难得的机会，可以结合研究特征响应环境变化的历史、当代和未来演变。拟议的进化生物学和农业交叉研究项目为 3 名博士、4 名硕士和 10 名理学学士 HQP 提供培训机会。对于可持续农业实践的发展，了解除草剂在农业杂草种群进化中所起的作用以及抗性进化是否有可能加剧或已达到稳定限度至关重要。该项目将对 HQP 进行现场生物学、实验设计、定量遗传学、统计学、基因组学和生物信息学以及口头和书面交流方面的培训 - 为 HQP 进行学术、工业和/或政府研究做好准备。