Evolutionary Genomics of Abiotic Stress Resistance in Wild and Cultivated Sunflowers

PI: John M. Burke（佐治亚-雅典大学）共同PI: Lisa A. Donovan（佐治亚-雅典大学），Loren H. Rieseberg（印第安纳大学），Khaled M. Bali（加州大学农业与自然资源学院），Pedro Andrade-Sanchez（亚利桑那大学），Jennifer M. Dechaine（华盛顿大学中部）主要合作伙伴：Jeffrey W. White （USDA-ARS/Maricopa）和Nicolas B. Langlade （INRA, France）野生和栽培植物经常受到干旱、土壤盐碱化和低养分利用率等因素造成的各种非生物胁迫的挑战。这些胁迫影响植物生长发育，降低作物产量。尽管野生植物种群已经适应了许多这些挑战，但作物的适应能力往往较差。这可能是由于抗逆性与整体生长/生产力之间的权衡，以及作物驯化和育种过程中遗传多样性的丧失。为了对抗压力导致的产量损失和改善粮食安全，人们的注意力已经转向开发抗压力作物，但这种努力需要知识。因此，需要更好地了解非生物抗逆性的潜在机制，以开发能够在气候日益变化的背景下养活快速增长的人口的作物，特别是在边际土地投入生产的情况下。在这个项目中进行的研究将产生重要的实际成果，最终将促进生产更具抗逆性的作物。这些成果包括产生关于抵抗限制农业生产力的非生物胁迫的分子和生理机制的可操作知识，可以从野生种群转移到下游育种计划的有利遗传变异的鉴定，以及有价值的种质资源的开发和分配。该项目还将为不同层次、不同背景的学生提供教育机会。该项目包括详细调查栽培向日葵及其生殖相容、应力适应野生物种的干旱、盐和低营养胁迫抗性的基因组和生理基础，这些野生物种是有益等位基因的潜在供体。向日葵是这项工作的理想研究系统，因为栽培向日葵的生产力明显受到这种胁迫的限制，而相关的野生物种适应各种极端环境的生活。本项目的目标是：(1)利用传统和高通量表型分析方法评估栽培向日葵及其野生近缘种的抗旱、耐盐、抗低营养胁迫及相关性状；(2)将栽培向日葵和野生向日葵非生物抗逆性和相关性状的变异与特定基因、调控网络和/或因果变异联系起来；(3)通过对具有不同胁迫反应的基因型进行深入的生理和转录组学表征，确定抗逆性的机制基础；(4)确定合适的抗逆境等位基因（即在多个遗传背景中表现出抗性的等位基因，理想情况下，最小的权衡）用于向日葵育种计划；(5)为不同背景的学生在植物科学领域的职业生涯做好准备。所有种质资源将通过存储在公共存储库（例如USDA-GRIN）中提供，结果数据将通过同行评审出版物、公开演讲和存储到相关公共数据库中传播，包括向日葵基因组数据库（http://www.sunflowergenome.org/）、HeliaGene向日葵数据库（http://www.heliagene.org/）、GenBank （http://www.ncbi.nlm.nih.gov/genbank/）、Phytozome （http://www.phytozome.net/）、Gene Expression Omnibus （http://ncbi.nlm.nih.gov/geo/）和Dryad （http://datadryad.org/）。

PI: John M. Burke (University of Georgia-Athens)Co-PIs: Lisa A. Donovan (University of Georgia-Athens), Loren H. Rieseberg (Indiana University), Khaled M. Bali (University of California Division of Agriculture & Natural Resources), Pedro Andrade-Sanchez (University of Arizona), and Jennifer M. Dechaine (Central Washington U.)Key Collaborators: Jeffrey W. White (USDA-ARS/Maricopa) and Nicolas B. Langlade (INRA, France)Wild and cultivated plants are regularly challenged by a variety of abiotic stresses resulting from factors such as drought, soil salinization, and low nutrient availability. These stresses affect plant growth and development and reduce crop productivity. Though wild plant populations have adapted to many of these challenges, crops are often less resilient. This is likely due to the occurrence of tradeoffs between stress resistance and overall growth/productivity, as well as the loss of genetic diversity during the domestication and breeding of crop plants. To combat stress-induced yield loss and improve food security, attention has turned to the development of stress-resistant crops, but such efforts require knowledge. An improved understanding of the mechanisms underlying abiotic stress resistance is thus needed to develop crops capable of feeding a rapidly growing population in the context of an increasingly variable climate, particularly as marginal lands are brought into production. The research conducted in this project will have important practical outcomes that will ultimately facilitate the production of more resilient crop plants. These outcomes include the production of actionable knowledge regarding the molecular and physiological mechanisms underlying resistance to abiotic stresses that limit agricultural productivity, the identification of favorable genetic variants that can be moved from wild populations into downstream breeding programs, and the development and distribution of valuable germplasm resources. This project will also provide educational opportunities for students at multiple levels, and from diverse backgrounds.This project involves a detailed investigation of the genomic and physiological basis of drought, salt, and low nutrient stress resistance in cultivated sunflower and its reproductively compatible, stress-adapted wild species that are potential donors of beneficial alleles. Sunflower is an ideal study system for this work because the productivity of cultivated sunflower is clearly limited by such stresses, while related wild species are adapted to life in a variety of extreme environments. The goals of this project are to: (1) assess resistance to drought, salt, and low nutrient stress and related traits in cultivated sunflower and its wild relatives using traditional and high-throughput phenotyping approaches; (2) associate variation in abiotic stress resistance and related traits in cultivated and wild sunflowers with specific genes, regulatory networks, and/or causal variants; (3) determine the mechanistic basis of stress resistance via in-depth physiological and transcriptomic characterization of genotypes with divergent stress responses; (4) identify suitable stress resistance alleles (i.e., those exhibiting resistance in multiple genetic backgrounds, ideally with minimal tradeoffs) for use in sunflower breeding programs; and (5) prepare students from diverse backgrounds for careers in the plants sciences. All germplasm resources will be made available via deposition in public repositories (e.g., USDA-GRIN) and the resulting data will be disseminated via peer-reviewed publications, public presentations, and deposition into relevant public databases including the sunflower genome database (http://www.sunflowergenome.org/), the HeliaGene sunflower database (http://www.heliagene.org/), GenBank (http://www.ncbi.nlm.nih.gov/genbank/), Phytozome (http://www.phytozome.net/), the Gene Expression Omnibus (http://ncbi.nlm.nih.gov/geo/), and Dryad (http://datadryad.org/).