title: Adaptation to low temperatures in the wild tomato species Solanum chilense.
abstract: Molecular adaptation to abiotic stresses in plants is a complex process based mainly on the modifications of gene transcriptional activity and the alteration of protein-protein interactions. We used a combination of population genetic, comparative transcriptomic and plant physiology approaches to investigate the mechanisms of adaptation to low temperatures in Solanum chilense populations distributed along Andean altitudinal gradients. We found that plants from all populations have high chilling tolerance, which does not correlate with temperatures in their native habitats. In contrast, tolerance to freezing shows a significant association with altitude and temperature variables. We also observed the differences in expression patterns of cold-response genes between plants from high- and low-altitude populations. These results suggest that genetic adaptations to low temperatures evolved in high-altitude populations of S. chilense. At the transcriptional level, these adaptations may include high levels of constitutive expression of the genes encoding ICE1, the key transcription factor of the cold signalling pathway, and chloroplast ω-3 fatty acid desaturase FAD7. At the sequence level, a signature of selection associated with the adaptation to high altitudes was detected at the C-terminal part of ICE1 encoding the ACT regulatory domain.
authors.affiliation: Section of Evolutionary Biology, Department of Biology II, Ludwig-Maximilians University of Munich, Großhaderner Str. 2, Planegg-Martinsried, 82152, Germany.
authors.forename: Tetyana
authors.initials: T
authors.lastname: Nosenko
authors.affiliation: Section of Evolutionary Biology, Department of Biology II, Ludwig-Maximilians University of Munich, Großhaderner Str. 2, Planegg-Martinsried, 82152, Germany.|Institute of Evolutionary Biology, University of Edinburgh, Ashworth Laboratories, King's Buildings, Charlotte Auerbach Road, Edinburgh, EH9, 3FL, UK.
authors.forename: Katharina B
authors.initials: KB
authors.lastname: Böndel
authors.affiliation: Section of Evolutionary Biology, Department of Biology II, Ludwig-Maximilians University of Munich, Großhaderner Str. 2, Planegg-Martinsried, 82152, Germany.
authors.forename: Gabriele
authors.initials: G
authors.lastname: Kumpfmüller
authors.affiliation: Section of Evolutionary Biology, Department of Biology II, Ludwig-Maximilians University of Munich, Großhaderner Str. 2, Planegg-Martinsried, 82152, Germany.|Museum für Naturkunde Berlin, Invalidenstr. 4, Berlin, 10115, Germany.
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Stephan
mesh_terms: D000222:Adaptation, Physiological / Q000235:genetics*; D000531:Altitude; D002677:Chile; D003080:Cold Temperature; D017753:Ecosystem; D005615:Freezing; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D005828:Genetics, Population; D010568:Peru; D010641:Phenotype; D032322:Solanum / Q000235:genetics*; D059467:Transcriptome
keywords: adaptation; cold-response pathway; multilocus selection; plant population genetics; wild tomatoes