Evolutionary genetics of vernalization responsiveness in the temperate grass subfamily Pooideae

温带禾本科早熟禾亚科春化反应的进化遗传学

• 批准号: 1353056
• 负责人: Jill Preston
• 金额: $ 42.2万
• 依托单位: University of Vermont & State Agricultural College
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-08-01 至 2019-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1353056&HistoricalAwards=false
• 关键词: Evolutionary; genetics; vernalization; responsiveness; temperate

Jill PrestonIOS-1353056Evolutionary Genetics of Vernalization Responsiveness in the Temperate Grass Subfamily PooideaeMost plant species integrate multiple environmental cues, such as day length and past winter chilling, to ready them to flower when local conditions are favorable. Not only does flowering time affect plant fitness, but also the yield of grains, fruits, and seeds available for human consumption. But how do plants in different climates know to vary their flowering times, and what happens as these local climates change over time? To address these questions, this project focuses on a geographically and ecologically diverse group of cereal crop and forage grasses with the aim of determining how flowering time has evolved at both the whole plant and genetic level under global cooling over the past 50 million years. By shedding light on the past, results of this study promise to allow better prediction of flowering time responses to current global change, and to isolate novel genes and genetic pathways for the potential manipulation of flowering time in crop grasses.The "pooid" grasses evolved from a tropical ancestor around 48 million years ago and have subsequently colonized a wide range of habitats in both the northern and southern temperate zones as global temperatures decreased. One of the major barriers to living in the temperate region is freezing temperatures, which are particularly detrimental to reproductive structures. The crop pooids barley, wheat, and oats are able to avoid flowering in winter by rapidly becoming competent to flower after an extended period of cold tempreatures (vernalization). However, it is unknown whether the evolution of the vernalization response was key to the diversification of all temperate pooids, or if it evolved more recently in separate grasses. To determine the evolutionary origin(s) and genetic basis of the vernalization response, the PI will work with students, a postdoctoral researcher, and computer scientists in the Vermont Genetics Network to carry out flowering time experiments on 40 species of pooid grasses collected from different latitudes across the world. The flowering time response of each species to cold temperatures will be mapped onto an evolutionary tree and models will be used to estimate when and how many times flowering in response to cold evolved. As a complement to this, genomic data will be collected to pinpoint similarities and differences in vernalization responsive gene expression between species. By determining different levels of plant responses to chilling, data from this project will facilitate critical insights into the complex adaptations of plants to their environments. Furthermore, activities and outcomes of this study will be used to foster interdisciplinary and active learning activities for high school to graduate students, paving the way for the next generation of successful organismal and evolutionary biologists.

Jill PrestonIOS-1353056温带草亚科春化反应的进化遗传学大多数植物物种将多种环境信号整合在一起，如白天长度和过去的冬季寒冷，以便在当地条件有利的时候开花。开花时间不仅影响植物的适合性，而且还影响可供人类食用的谷物、水果和种子的产量。但是，不同气候中的植物如何知道改变它们的开花时间，以及随着时间的推移，这些当地气候发生了什么变化？为了解决这些问题，该项目侧重于地理和生态多样性的一组谷类作物和牧草，目的是确定在过去5000万年全球变冷的情况下，整个植物和遗传水平的开花时间是如何演变的。通过揭示过去的情况，这项研究的结果有望更好地预测开花时间对当前全球变化的反应，并分离出新的基因和遗传途径，用于潜在地操纵作物草的开花时间。大约4800万年前的热带祖先进化而来，随后随着全球气温的下降，杂草在南北温带的广泛栖息地定居。在温带地区生活的主要障碍之一是严寒，这对生殖结构特别有害。豆荚类作物大麦、小麦和燕麦在经过较长一段时间的低温(春化)后，迅速变得有能力开花，从而能够避免冬季开花。然而，尚不清楚春化反应的进化是否是所有温带瓢虫多样化的关键，或者它是否最近在不同的牧草中进化。为了确定春化反应的进化起源(S)和遗传基础，PI将与学生、博士后研究员和佛蒙特州遗传学网络的计算机科学家合作，对从世界不同纬度收集的40种杂草进行开花时间实验。每个物种对寒冷温度的开花时间反应将被映射到进化树上，并将使用模型来估计何时以及多少次开花对寒冷的反应进化。作为补充，将收集基因组数据，以查明不同物种之间春化反应基因表达的相似和差异。通过确定植物对低温反应的不同水平，该项目的数据将有助于深入了解植物对环境的复杂适应。此外，这项研究的活动和成果将被用来促进高中到研究生的跨学科和积极的学习活动，为下一代成功的生物学家和进化生物学家铺平道路。