Evolutionary genetics of vernalization responsiveness in the temperate grass subfamily Pooideae

温带禾本科植物春化反应的进化遗传学大多数植物综合多种环境因素，如日照长度和过去冬季的寒冷程度，以便在当地条件有利时开花。开花时间不仅影响植物的适应性，还影响可供人类食用的谷物、水果和种子的产量。但是，不同气候下的植物是如何知道它们的开花时间变化的呢？随着时间的推移，这些当地气候会发生什么变化呢？为了解决这些问题，该项目将重点放在地理和生态多样性的谷类作物和饲草上，目的是确定在过去5000万年全球变冷的情况下，开花时间在整个植物和遗传水平上是如何进化的。通过对过去的揭示，本研究的结果有望更好地预测开花时间对当前全球变化的响应，并为农作物开花时间的潜在操纵分离新的基因和遗传途径。“类”草大约在4800万年前从热带祖先进化而来，随着全球气温的下降，它们随后在北温带和南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寒冷的气温，这对生殖结构尤其有害。大麦、小麦和燕麦等作物在经过长时间的低温（春化）后迅速变得有能力开花，从而能够避免在冬季开花。然而，尚不清楚春化反应的进化是否是所有温带类群多样化的关键，或者它是否在最近的不同禾本科中进化。为了确定春化反应的进化起源和遗传基础，PI将与佛蒙特州遗传学网络的学生，博士后研究员和计算机科学家合作，对从世界不同纬度收集的40种类草进行开花时间实验。每个物种对低温的开花时间反应将被映射到进化树上，模型将被用来估计何时和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，以查明物种之间春化反应基因表达的异同。通过确定植物对寒冷的不同反应水平，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，本研究的活动和成果将用于促进高中到研究生的跨学科和主动学习活动，为下一代成功的生物和进化生物学家铺平道路。

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.