Evolutionary Genomics of Abiotic Stress Resistance in Wild and Cultivated Sunflowers

PI：John M.伯克（佐治亚大学-雅典分校）合作PI：丽莎A。Donovan（University of Georgia-Athens），Loren H. Rieseberg（印第安纳州大学），Khaled M. Bali（加州大学农业自然资源部）、Pedro Andrade-Sanchez（亚利桑那大学）和Jennifer M. Dechaine（中央华盛顿U.）主要合作者：Jeffrey W.白色（USDA-ARS/Marvala）和Nicolas B。Langlade（INRA，法国）野生和栽培植物经常受到各种非生物胁迫的挑战，这些非生物胁迫是由干旱、土壤盐碱化和低养分可用性等因素造成的。这些压力影响植物生长和发育，降低作物产量。尽管野生植物种群已经适应了其中许多挑战，但作物的适应力往往较弱。这可能是由于胁迫抗性和整体生长/生产力之间的权衡，以及作物植物驯化和育种过程中遗传多样性的丧失。为了防止压力引起的产量损失和改善粮食安全，人们的注意力转向了抗压力作物的开发，但这种努力需要知识。因此，需要更好地了解抗非生物胁迫的机制，以便在气候日益多变的情况下，特别是在边际土地投入生产的情况下，开发能够养活迅速增长的人口的作物。在该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弹性的作物。这些成果包括产生关于限制农业生产力的非生物胁迫抗性的分子和生理机制的可操作知识，鉴定可以从野生种群转移到下游育种计划的有利遗传变异，以及开发和分配有价值的种质资源。本项目还将为来自不同背景的学生提供多层次的教育机会。本项目涉及对栽培向日葵及其繁殖相容性、适应压力的野生物种的抗旱性、盐和低营养胁迫抗性的基因组和生理基础的详细调查，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显然受到这种压力的限制，而相关的野生物种适应各种极端环境中的生活。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对干旱、盐和低营养胁迫的抗性及相关性状;（2）将栽培向日葵和野生向日葵的非生物胁迫抗性及相关性状的变异与特定基因、调控网络和/或因果变异相关联;（3）通过对具有不同胁迫反应的基因型进行深入的生理学和转录组学表征来确定胁迫抗性的机制基础;（4）鉴定合适的胁迫抗性等位基因（即，那些在多种遗传背景中表现出抗性的，理想情况下具有最小的权衡）用于向日葵育种计划;以及（5）为来自不同背景的学生在植物科学中的职业生涯做好准备。所有种质资源将通过存放在公共储存库（例如，USDA-GRIN），并将通过同行评审的出版物、公开演示和存入相关公共数据库（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/））传播所得数据。

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/).