Department of Ecology and Evolution, University of Chicago, Chicago, Illinois 60637.
Genetics. 2014 Feb;196(2):569-77. doi: 10.1534/genetics.113.157628. Epub 2013 Nov 26.
Climate change has altered life history events in many plant species; however, little is known about genetic variation underlying seasonal thermal response. In this study, we simulated current and three future warming climates and measured flowering time across a globally diverse set of Arabidopsis thaliana accessions. We found that increased diurnal and seasonal temperature (1°-3°) decreased flowering time in two fall cohorts. The early fall cohort was unique in that both rapid cycling and overwintering life history strategies were revealed; the proportion of rapid cycling plants increased by 3-7% for each 1° temperature increase. We performed genome-wide association studies (GWAS) to identify the underlying genetic basis of thermal sensitivity. GWAS identified five main-effect quantitative trait loci (QTL) controlling flowering time and another five QTL with thermal sensitivity. Candidate genes include known flowering loci; a cochaperone that interacts with heat-shock protein 90; and a flowering hormone, gibberellic acid, a biosynthetic enzyme. The identified genetic architecture allowed accurate prediction of flowering phenotypes (R(2) > 0.95) that has application for genomic selection of adaptive genotypes for future environments. This work may serve as a reference for breeding and conservation genetic studies under changing environments.
气候变化改变了许多植物物种的生活史事件；然而，对于季节热响应的遗传变异知之甚少。在这项研究中，我们模拟了当前和三种未来的变暖气候，并测量了全球多样化的拟南芥（Arabidopsis thaliana）品系的开花时间。我们发现，昼夜和季节温度（1°-3°）的升高会缩短两个秋季群体的开花时间。秋季早批群体的独特之处在于，它揭示了快速循环和越冬两种生活史策略；每升高 1°，快速循环植物的比例增加了 3-7%。我们进行了全基因组关联研究（GWAS），以确定热敏感性的潜在遗传基础。GWAS 确定了控制开花时间的五个主要效应数量性状位点（QTL），以及另外五个具有热敏感性的 QTL。候选基因包括已知的开花基因座；一种与热休克蛋白 90 相互作用的伴侣蛋白；以及一种开花激素赤霉素，一种生物合成酶。所确定的遗传结构允许对开花表型进行准确预测（R(2)>0.95），这对于未来环境中适应性基因型的基因组选择具有应用价值。这项工作可以作为在不断变化的环境中进行繁殖和保护遗传研究的参考。
