The genetic basis and adaptive significance of pleiotropy: FLC-regulated germination and flowering

“物候学”，即生物事件如发芽和开花的时间，是植物对气候变化最重要的反应之一，它已被证明会影响植物的生长和局部灭绝。不同的生命阶段必须对季节性的环境线索做出适当的反应，以使它们的发展与相应的季节相匹配。该项目旨在了解两个关键物候事件“发芽和开花”的时间如何适应季节变化，即使它们具有共同的遗传基础，并且必须对相似的季节环境线索做出不同的反应。多效性是指一个基因控制一个以上的性状。理解多种性状在同一基因控制下如何适应是一个重大挑战。最近，人们发现拟南芥开花通路中的基因也能调控种子萌发，从而为研究多效性的遗传基础和适应意义提供了强有力的研究体系。开花基因座C （FLC）是植物开花的主要调控因子，是植物适应性显著性状的分子调控途径之一，已成为生态遗传学的经典系统。最近的研究发现，FLC-开花途径的直接下游元件也控制着种子的萌发行为，并且FLC的自然变化与温度依赖性萌发的自然变化有关。本项目旨在表征FLC及其通路中其他元件对萌发和开花物候的多效性作用，确定FLC介导的通路自然变异的来源，并测量FLC（及FLC通路）变异在萌发和开花过程中的适应度后果。本研究探讨了物候和环境因子的遗传基础。因此，该项目将提供植物如何应对环境变化的基本信息。该项目还将产生基因组数据和遗传物质，这些数据和遗传物质将通过拟南芥信息资源提供给研究界。该项目将为一名博士后、一名研究生、一名研究助理、几名本科生和高中生提供分子遗传学和生态遗传学方面的就业机会和培训。还将设计一个教育模块，使学生能够探索遗传途径如何影响生物体对环境变化的反应。

"Phenology", the timing of biological events such as germination and flowering, is one of the most important responses of plants to climate change, and it has been shown to influence performance and local extinctions. Different life stages must respond appropriately to seasonal environmental cues to match their development with the corresponding season. This project seeks to understand how the timing of two crucial phenological events, "germination and flowering" can adapt to seasonal variation even though they share a common genetic basis and must respond differently to similar seasonal environmental cues. Pleiotropy occurs when one gene controls more than one trait. Understanding how multiple traits can adapt when they are controlled by the same genes is a major challenge. Genes in a well known flowering pathway in Arabidopsis thaliana have recently been found to also regulate germination, thereby providing a powerful research system for investigating the genetic basis and adaptive significance of pleiotropy. The major regulator of flowering, FLOWERING LOCUS C (FLC), operates in a pathway that is one of the best characterized molecular pathways of an adaptively significant trait in plants, and it has become a classic system in ecological genetics. It was recently found that the immediate downstream elements in the FLC-flowering pathway also control the germination behavior of seeds, and that natural variation in FLC is associated with natural variation in temperature-dependent germination. This project aims to characterize pleiotropic effects of FLC and other elements in its pathway on both germination and flowering phenology, identify sources of natural variation in FLC-mediated pathways, and measure the fitness consequences of FLC (and FLC-pathway) variation operating through germination and flowering. This research explores the genetic basis of phenology and environmental cuing. As such, the project will provide basic information on how plants respond to environmental change. The project will also generate genomic data and genetic material that will be made available to the research community through The Arabidopsis Information Resource. This project will provide career opportunities and training in molecular genetics and ecological genetics to a postdoc, a graduate student, a research assistant, several undergraduates, and high school students. An educational module will be designed also so that students can explore how genetic pathways influence organismal responses to environmental change.