title: Genetic Architecture of Natural Variation in Thermal Responses of Arabidopsis.
abstract: Wild strains of Arabidopsis (Arabidopsis thaliana) exhibit extensive natural variation in a wide variety of traits, including response to environmental changes. Ambient temperature is one of the major external factors that modulates plant growth and development. Here, we analyze the genetic architecture of natural variation in thermal responses of Arabidopsis. Exploiting wild accessions and recombinant inbred lines, we reveal extensive phenotypic variation in response to ambient temperature in distinct developmental traits such as hypocotyl elongation, root elongation, and flowering time. We show that variation in thermal response differs between traits, suggesting that the individual phenotypes do not capture all the variation associated with thermal response. Genome-wide association studies and quantitative trait locus analyses reveal that multiple rare alleles contribute to the genetic architecture of variation in thermal response. We identify at least 20 genomic regions that are associated with variation in thermal response. Further characterizations of temperature sensitivity quantitative trait loci that are shared between traits reveal a role for the blue-light receptor CRYPTOCHROME2 (CRY2) in thermosensory growth responses. We show the accession Cape Verde Islands is less sensitive to changes in ambient temperature, and through transgenic analysis, we demonstrate that allelic variation at CRY2 underlies this temperature insensitivity across several traits. Transgenic analyses suggest that the allelic effects of CRY2 on thermal response are dependent on genetic background suggestive of the presence of modifiers. In addition, our results indicate that complex light and temperature interactions, in a background-dependent manner, govern growth responses in Arabidopsis.
authors.affiliation: School of Biological Sciences, Monash University, Clayton, Victoria 3800, Australia.
authors.forename: Eduardo
authors.identifier: http://orcid.org/0000-0001-8151-4465
authors.initials: E
authors.lastname: Sanchez-Bermejo
authors.affiliation: School of Biological Sciences, Monash University, Clayton, Victoria 3800, Australia.
authors.forename: Wangsheng
authors.initials: W
authors.lastname: Zhu
authors.affiliation: School of Biological Sciences, Monash University, Clayton, Victoria 3800, Australia.
authors.forename: Celine
authors.initials: C
authors.lastname: Tasset
authors.affiliation: School of Biological Sciences, Monash University, Clayton, Victoria 3800, Australia.
authors.forename: Hannes
authors.initials: H
authors.lastname: Eimer
authors.affiliation: School of Biological Sciences, Monash University, Clayton, Victoria 3800, Australia.
authors.forename: Sridevi
authors.initials: S
authors.lastname: Sureshkumar
authors.affiliation: School of Biological Sciences, Monash University, Clayton, Victoria 3800, Australia.
authors.forename: Rupali
authors.initials: R
authors.lastname: Singh
authors.affiliation: School of Biological Sciences, Monash University, Clayton, Victoria 3800, Australia.
authors.forename: Vignesh
authors.initials: V
authors.lastname: Sundaramoorthi
authors.affiliation: School of Biological Sciences, Monash University, Clayton, Victoria 3800, Australia.
authors.forename: Luana
authors.initials: L
authors.lastname: Colling
authors.affiliation: School of Biological Sciences, Monash University, Clayton, Victoria 3800, Australia mb.suresh@monash.edu.
authors.forename: Sureshkumar
authors.identifier: http://orcid.org/0000-0002-1057-2606
authors.initials: S
authors.lastname: Balasubramanian
mesh_terms: D000483:Alleles; D017360:Arabidopsis / Q000235:genetics* / Q000502:physiology*; D029681:Arabidopsis Proteins / Q000235:genetics; D056931:Cryptochromes / Q000235:genetics; D059647:Gene-Environment Interaction; D017343:Genes, Plant; D014644:Genetic Variation; D055106:Genome-Wide Association Study; D018546:Hypocotyl / Q000254:growth & development; D007178:Inbreeding; D040641:Quantitative Trait Loci / Q000235:genetics; D013696:Temperature
chemical_list: D029681:Arabidopsis Proteins; C103618:CRY2 protein, Arabidopsis; D056931:Cryptochromes