title: Natural variation involving deletion alleles of FRIGIDA modulate temperature-sensitive flowering responses in Arabidopsis thaliana.
abstract: Ambient temperature is one of the major environmental factors that modulate plant growth and development. There is extensive natural genetic variation in thermal responses of plants exemplified by the variation exhibited by the accessions of Arabidopsis thaliana. In this work we have studied the enhanced temperature response in hypocotyl elongation and flowering shown by the Tsu-0 accession in long days. Genetic mapping in the Col-0 × Tsu-0 recombinant inbred line (RIL) population identified several QTLs for thermal response including three major effect loci encompassing candidate genes FRIGIDA (FRI), FLOWERING LOCUS C (FLC) and FLOWERING LOCUS T (FT). We confirm and validate these QTLs. We show that the Tsu-0 FRI allele, which is the same as FRI-Ler is associated with late flowering but only at lower temperatures in long days. Using transgenic lines and accessions, we show that the FRI-Ler allele confers temperature-sensitive late flowering confirming a role for FRI in photoperiod-dependent thermal response. Through quantitative complementation with heterogeneous inbred families, we further show that cis-regulatory variation at FT contributes to the observed hypersensitivity of Tsu-0 to ambient temperature. Overall our results suggest that multiple loci that interact epistatically govern photoperiod-dependent thermal responses of A. thaliana.
authors.affiliation: School of Biological Sciences, Monash University, Clayton Campus, VIC, 3800, Australia.
authors.forename: Eduardo
authors.initials: E
authors.lastname: Sanchez-Bermejo
authors.affiliation: School of Biological Sciences, Monash University, Clayton Campus, VIC, 3800, Australia.
authors.forename: Sureshkumar
authors.identifier: 0000-0002-1057-2606
authors.initials: S
authors.lastname: Balasubramanian
mesh_terms: D000483:Alleles; D017360:Arabidopsis / Q000254:growth & development* / Q000502:physiology; D029681:Arabidopsis Proteins / Q000235:genetics / Q000502:physiology*; D035264:Flowers / Q000254:growth & development* / Q000502:physiology; D017353:Gene Deletion; D014644:Genetic Variation / Q000502:physiology; D018546:Hypocotyl / Q000254:growth & development / Q000502:physiology; D026161:MADS Domain Proteins / Q000235:genetics / Q000502:physiology; D017440:Photoperiod; D030821:Plants, Genetically Modified; D040641:Quantitative Trait Loci; D013696:Temperature
chemical_list: D029681:Arabidopsis Proteins; C418902:At5g10140 protein, Arabidopsis; C414613:FRI protein, Arabidopsis; C418905:FT protein, Arabidopsis; D026161:MADS Domain Proteins
keywords: QTL analysis; ambient temperature; epistatic interactions; flowering time; natural variation