Location: Soil and Water Management ResearchTitle: Genetic variation for life history sensitivity to seasonal warming in Arabidopsis thaliana Author
Submitted to: Genetics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/12/2013
Publication Date: 11/26/2013
Publication URL: http://handle.nal.usda.gov/10113/59580
Citation: Li, Y., Cheng, R., Spokas, K.A., Palmer, A., Borevitz, J. 2013. Genetic variation for life history sensitivity to seasonal warming in Arabidopsis thaliana. Genetics. 196:569-577. Interpretive Summary: The natural genetic variation underlying fall seasonal temperature regulation of flowering time is important life history trait underlying plant fitness. Life history events have been altered in many species due to global warming, but little is known about the population and quantitative genetic variation underlying such responses. This knowledge is necessary in order to predict how species may adapt under new environments. This study was unique in that current and future climates were simulated in growth chambers where powerful Genome Wide Association Studies (GWAS) revealed candidate genes sensitive to climate warming. This study with Arabidopsis is a template for crop and foundation species, where whole genome analysis of standing genetic variation can reveal genes for breeding and conservation under changing environments. These findings could provide additional insights and direction in the focus of the adaptability of agronomic crops to climate change. These results are significant to farmers and policy makers and will assist scientists and engineers in developing an improved understanding in the alterations of plant species as a function of climate change.
Technical Abstract: 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 to 3°C) 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°C 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 co-chaperone that interacts with Heat Shock Protein 90, and a flowering hormone, Gibberellic Acid, biosynthetic enzyme. The identified genetic architecture allowed accurate prediction of flowering phenotypes (R2 > 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.