Dissertation Research: Adaptive Evolution of Seed Oil Composition in Arabidopsis thaliana

实验证据支持这样一种观点，即种子油的成分，即种子油中饱和脂肪酸和不饱和脂肪酸的相对比例，已经适应了温度，因此在寒冷气候下生活的植物中，种子油的熔点较低。本研究的目的是确定种子油成分适应性差异的遗传基础，并将其与特定的生态选择压力联系起来。利用遗传和分子技术，将鉴定导致这一复杂性状变异的单个基因，并测试不同等位基因的适应价值。这个项目将是第一个确定导致复杂性状进化的遗传变异的项目之一。植物油是有机碳中能量最丰富的形式之一；它们被广泛用于人类营养、工业产品和生物燃料。了解油的成分是如何随着温度的变化而进化的，可以帮助我们为工业目的设计油的成分，比如改善生物柴油的低温性能，减少食品中难吃的脂肪酸。对种子油成分的进化知识导致了低饱和脂肪野生向日葵的发现，这些向日葵被用于生产市售的低饱和脂肪向日葵系列。本项目将为本科生提供研究进化遗传学的机会。

Experimental evidence supports the idea that seed oil composition, the relative proportions of saturated and unsaturated fatty acids in seed oils, has adapted to temperature such that the melting point of the seed oil is lower in plants that live in colder climates. The aim of this research is to determine the genetic basis of adaptive differences in seed oil composition and tie them to specific ecological selective pressures. Using genetic and molecular techniques, the individual genes underlying the variation in this complex trait will be identified and the adaptive value of different alleles tested. This project will be one of the first to identify the genetic variation responsible for the evolution of a complex trait. Plant oils are one of the most energy rich forms of organic carbon; they are widely utilized for human nutrition, industrial products, and biofuels. Understanding how oil composition has evolved in response to temperature may help us engineer oil composition for industrial purposes such as improving cold temperature performance of biodiesels and reducing unpalatable fatty acids in food products. Evolutionary knowledge of seed oil composition led to the discovery of low saturated fat wild sunflowers, which were used to produce commercially available low saturated fat sunflower lines. This project will provide undergraduates with research opportunities in evolutionary genetics.