Genome‐wide signatures of flowering adaptation to climate temperature: Regional analyses in a highly diverse native range of Arabidopsis thaliana

• Published in: Plant, cell and environment Vol. 41; no. 8; pp. 1806 - 1820
• Main Authors: Tabas‐Madrid, Daniel, Méndez‐Vigo, Belén, Arteaga, Noelia, Marcer, Arnald, Pascual‐Montano, Alberto, Weigel, Detlef, Xavier Picó, F., Alonso‐Blanco, Carlos
• Format: Journal Article
• Language: English
• Published: United States Wiley Subscription Services, Inc 01.08.2018
• Subjects: Adaptation; Arabidopsis; Arabidopsis thaliana; Casein; Casein kinase II; Climate; Climate adaptation; Collection; Demographics; Dispersal; Flowering; FRIGIDA‐like 1 (FRL1); Genes; Genetic diversity; Genomes; genome‐wide association (GWA); genomic; Ion channels; Molecular chains; Molecular modelling; Mountains; Phenotypes; Plant populations; Regional analysis; Single-nucleotide polymorphism; temperature; Temperature effects; Twin Sister of FT (TSF); Voltage‐Dependent Anion Channel 5 (VDAC5); genome-wide association (GWA); Arabidopsis; genomic; Twin Sister of FT (TSF); temperature; adaptation; FRIGIDA-like 1 (FRL1); climate; flowering; Voltage-Dependent Anion Channel 5 (VDAC5)
• ISSN: 0140-7791; 1365-3040
• DOI: 10.1111/pce.13189

Current global change is fueling an interest to understand the genetic and molecular mechanisms of plant adaptation to climate. In particular, altered flowering time is a common strategy for escape from unfavourable climate temperature. In order to determine the genomic bases underlying flowering time adaptation to this climatic factor, we have systematically analysed a collection of 174 highly diverse Arabidopsis thaliana accessions from the Iberian Peninsula. Analyses of 1.88 million single nucleotide polymorphisms provide evidence for a spatially heterogeneous contribution of demographic and adaptive processes to geographic patterns of genetic variation. Mountains appear to be allele dispersal barriers, whereas the relationship between flowering time and temperature depended on the precise temperature range. Environmental genome‐wide associations supported an overall genome adaptation to temperature, with 9.4% of the genes showing significant associations. Furthermore, phenotypic genome‐wide associations provided a catalogue of candidate genes underlying flowering time variation. Finally, comparison of environmental and phenotypic genome‐wide associations identified known (Twin Sister of FT, FRIGIDA‐like 1, and Casein Kinase II Beta chain 1) and new (Epithiospecifer Modifier 1 and Voltage‐Dependent Anion Channel 5) genes as candidates for adaptation to climate temperature by altered flowering time. Thus, this regional collection provides an excellent resource to address the spatial complexity of climate adaptation in annual plants. Despite flowering time is the best studied plant trait involved in climatic adaptation and, especially, to climate temperature, the mechanisms underlying such adaptation remain largely unknown. In this study, we aim to determine the genomic and molecular bases of flowering time adaptation to climate temperature using genome‐wide association (GWA) approaches in the model plant Arabidopsis thaliana. In contrast to most previous GWA studies that are based in world‐wide collections of accessions, we have carried out a regional study in a highly diverse native region. In addition, we have exploited not only phenotypic GWA analyses but also environmental GWA comparisons.