DISSERTATION RESEARCH: Evolution of hyperaccumulation in wild Helianthus: a phylogenetically explicit assessment of evolutionary history and adaptive hypotheses

论文研究：野生向日葵超积累的进化：对进化历史和适应性假设的系统发育明确评估

• 批准号: 1501215
• 负责人: Lisa Donovan
• 金额: $ 1.94万
• 依托单位: University of Georgia Research Foundation Inc
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-04-01 至 2018-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1501215&HistoricalAwards=false
• 关键词: DISSERTATION; RESEARCH; Evolution; hyperaccumulation; wild

Over 500 species of flowering plants are metal hyperaccumulators, meaning they possess the ability to take up extremely high concentrations of normally toxic metals into their shoot tissues. This natural ability may be harnessed for useful technological applications, including phytoremediation (the use of plants for environmental cleanup of polluted areas) as well as biofortification (the enrichment of crops with key nutrients like iron). The broad objective of the proposed research is to understand how the development of metal hyperaccumulation ability depends on metal tolerance, and how hyperaccumulation ability may benefit wild plants. Proposed benefits of hyperaccumulation to plants have included reduced herbivory and disease, improved drought tolerance, and reduced competition. This research will test these proposed benefits using the genus Helianthus (the sunflowers), a group of diverse species found in habitats across North America. Sunflowers are known to many for the agriculturally and horticulturally important crop species Helianthus annuus, which is itself a known hyperaccumulator of at least five different heavy metals. In addition to improving our understanding of plant ecology, this research will provide direct insights into hyperaccumulator physiology for the improved breeding and use of sunflower in technological applications.The evolutionary interactions of metal tolerance and metal hyperaccumulation will be assessed using 35 wild Helianthus species, through a manipulative greenhouse study generating a soil nickel gradient consisting of ten separate treatment levels, in which the evolution of tolerance and hyperaccumulation are parsed apart as separate and distinct traits. The putative costs and benefits of hyperaccumulation will be examined in greenhouse experiments which will quantify fitness-related costs while simultaneously evaluating five leading adaptive hypotheses. A phylogenetically explicit approach to the study of metal hyperaccumulation evolution can dramatically improve the understanding of the ecological and evolutionary context of metal hyperaccumulation. More broadly, this research will promote further development of the newly emerging field of evolutionary toxicology and will implement novel phylogenetic comparative methods for assessing environmentally responsive traits, allowing for an improved range of tools to address existing and emerging environmental concerns.

超过500种的开花植物是金属高积累剂，这意味着它们具有将正常有毒金属浓度的极高浓度的能力进入芽组织。可以利用这种自然能力来用于有用的技术应用，包括植物修复（使用植物来清理污染区域）以及生物强化（富含用铁等关键营养素的农作物富集）。拟议的研究的广泛目标是了解金属过度蓄积能力的发展如何取决于金属耐受性，以及如何使野生植物受益。提议的对植物过度蓄积的好处包括减少草食和疾病，提高了干旱耐受性以及竞争降低。这项研究将使用Helianthus属（向日葵）测试这些提议的益处，这是北美栖息地中发现的一组不同的物种。向日葵在农业和园艺上重要的农作物物种Helianthus Annuus众所周知，它本身就是至少五种不同的重金属的已知高积累剂。除了提高我们对植物生态学的理解外，这项研究还将直接见解超级污染子生理学，以改善在技术应用中在技术应用中改善葵花籽的繁殖和使用。金属耐受性和金属超值耗竭的进化相互作用将通过35种野生鸟类进行评估，通过35种野生鸟类，通过TOL进行验证，该水平的持续性均匀的治疗量，该水平的固定水平是土壤矿体层次的，该水平的水平与土壤层次的层次分开，该水平分别构成型号的水平，该水平的水平与土壤矿体层次分别，构成型号的水平。超积累作为单独且不同的特征分开。在温室实验中将检查推定的成本和优势，这些实验将量化与健身相关的成本，同时评估五个主要的自适应假设。对金属高蓄能进化的研究的系统发育方法可以极大地改善对金属高蓄积的生态和进化环境的理解。更广泛地说，这项研究将促进进化毒理学新兴领域的进一步发展，并将实施新型的系统发育比较方法来评估环境响应迅速的特征，从而改善了解决现有和新兴环境问题的工具范围。