Genomics of adaptation to agriculture in Striga hermonthica, a plant parasite of cereals

这一行动为NSF国家植物基因组计划2017财年生物学博士后研究奖学金提供了资金。该奖学金支持在东道主实验室为该研究员制定的研究和培训计划，该研究员还提出了扩大生物学参与度的计划。该奖学金的主办机构是宾夕法尼亚州立大学，赞助科学家是杰西·拉斯基博士。农艺杂草对农业生产力构成严重威胁，在气候变化的情况下，杂草侵扰可能会加剧。为了更好地了解生物和非生物应激源之间的相互作用，本项目研究了紫色独脚金对不同寄主作物和非生物环境的专化机制。寄生杂草对撒哈拉以南非洲的粮食生产构成了最大的生物制约，并破坏了玉米、高粱、谷子和大米等重要经济谷物的产量。更广泛的影响包括产生新的基因组和表型资源，以加强抗病作物品种的开发，培训本科生，以及针对非洲科学家的独脚金生物信息学讲习班。培训目标包括统计进化基因组学、古代DNA测序、数量遗传学和实验植物-寄生虫相互作用。该项目的主要目标是更好地了解不同非生物环境中作物-寄生虫相互作用的进化。首先，将利用过去150年来从东非和西非不同来源的不同宿主收集的200个标本的有针对性的外显子组测序，确定宿主专门化和局部适应的基因组特征。将确定与环境和原产地寄主具有统计关联的基因座，以及跟踪区域寄主作物产量随时间变化的等位基因变异。对于第二个目标，将从实验上评估非生物胁迫对寄主范围的影响。在氮素和水分限制条件下，将对三种农业重要寄主作物：高粱、谷子和玉米的60种基因型的20个寄生虫种群的种子萌发、早期寄主寻找行为和寄主抗性进行量化。项目期间产生的基因组和表型资源将通过在线数据库(NCBI；Project Unity，http://phenome-networks.com)和一个专门的项目网站，包括教学材料、代码和分子方案)向公众开放。

This action funds an NSF National Plant Genome Initiative Postdoctoral Research Fellowship in Biology for FY 2017. The fellowship supports a research and training plan in a host laboratory for the Fellow who also presents a plan to broaden participation in biology. The host institution for the fellowship is Pennsylvania State University and the sponsoring scientist is Dr. Jesse Lasky. Agronomic weeds pose a serious threat to agricultural productivity, and weed infestations may intensify under changing climates. To better understand interactions between biotic and abiotic stressors, this project investigates mechanisms of specialization to different host crops and abiotic environments in purple witchweed (Striga hermonthica). Parasitic witchweeds constitute the greatest biotic constraint to food production in sub-Saharan Africa and devastate yields of economically important cereals such as maize, sorghum, millet, and rice. Broader impacts include generation of new genomic and phenotypic resources to enhance development of resistant crop varieties, training of undergraduate students, and workshops in witchweed bioinformatics targeted to African scientists. Training objectives include statistical evolutionary genomics, ancient DNA sequencing, quantitative genetics, and experimental plant-parasite interactions.The main goal of this project is to better understand evolution of crop-parasite interactions across diverse abiotic environments. First, genomic signatures of host-specialization and local adaptation will be identified, using targeted exome sequencing of 200 herbarium specimens collected within the past 150 years from different hosts of origin across East and West Africa. Loci will be identified that exhibit statistical associations with environment and host of origin, with allelic variation that tracks change in regional host crop production over time. For the second aim, effects of abiotic stress on host range will be experimentally evaluated. Seed germination, early host-seeking behavior, and host resistance will be quantified under nitrogen- and water-limitation for 20 parasite populations across 60 genotypes of three agriculturally important host crops: sorghum, millet, and maize. Genomic and phenotypic resources generated during the project will be publicly accessible through online databases (NCBI; Project Unity, http://phenome-networks.com) and a dedicated project website including instructional materials, code, and molecular protocols.