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

该行动资助了2017财年NSF国家植物基因组计划生物学博士后研究奖学金。该研究金支持研究员在东道实验室的研究和培训计划，研究员还提出了扩大生物学参与的计划。该研究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，杂草侵扰可能加剧。为了更好地了解生物和非生物胁迫之间的相互作用，本项目研究了紫色独脚金（Striga hermonthica）对不同寄主作物和非生物环境的专化机制。 寄生独脚金是撒哈拉以南非洲粮食生产的最大生物制约因素，影响玉米、高粱、小米和水稻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，以促进抗性作物品种的开发，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DNA测序、数量遗传学和实验性植物-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，将使用在过去150年内从东非和西非不同来源的宿主中收集的200个植物标本标本的靶向外显子组测序，确定宿主专业化和地方适应的基因组特征。位点将被确定，表现出与环境和主机的原产地，与等位基因变异，跟踪随着时间的推移在区域宿主作物生产的变化的统计关联。对于第二个目标，非生物胁迫对宿主范围的影响将进行实验评估。种子萌发，早期寄主寻找行为和宿主抗性将在氮和水限制下，对三种重要的农业宿主作物（高粱，小米和玉米）的60种基因型中的20种寄生虫种群进行量化。 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）和专用项目网站（包括教学材料，代码和分子方案）公开访问。

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.