title: PIF4 and ELF3 Act Independently in Arabidopsis thaliana Thermoresponsive Flowering.
abstract: Plants have evolved elaborate mechanisms controlling developmental responses to environmental stimuli. A particularly important stimulus is temperature. Previous work has identified the interplay of PIF4 and ELF3 as a central circuit underlying thermal responses in Arabidopsis thaliana. However, thermal responses vary widely among strains, possibly offering mechanistic insights into the wiring of this circuit. ELF3 contains a polyglutamine (polyQ) tract that is crucial for ELF3 function and varies in length across strains. Here, we use transgenic analysis to test the hypothesis that natural polyQ variation in ELF3 is associated with the observed natural variation in thermomorphogenesis. We found little evidence that the polyQ tract plays a specific role in thermal responses beyond modulating general ELF3 function. Instead, we made the serendipitous discovery that ELF3 plays a crucial, PIF4-independent role in thermoresponsive flowering under conditions more likely to reflect field conditions. We present evidence that ELF3 acts through the photoperiodic pathway, pointing to a previously unknown symmetry between low and high ambient temperature responses. Moreover, in analyzing two strain backgrounds with different thermal responses, we demonstrate that responses may be shifted rather than fundamentally rewired across strains. Our findings tie together disparate observations into a coherent framework in which multiple pathways converge in accelerating flowering in response to temperature, with some such pathways modulated by photoperiod.
authors: University of Washington Department of Genome Sciences, Seattle, United States of America.
authors: Maximilian O
authors: http://orcid.org/0000-0001-9233-2157
authors: MO
authors: Press
authors: University of Washington Molecular and Cellular Biology Program, University of Washington Department of Biology, Seattle, United States of America.
authors: Amy
authors: A
authors: Lanctot
authors: University of Washington Department of Genome Sciences, Seattle, United States of America.
authors: Christine
authors: C
authors: Queitsch
mesh_terms: D017360:Arabidopsis / Q000235:genetics* / Q000502:physiology; D029681:Arabidopsis Proteins / Q000235:genetics / Q000502:physiology*; D051792:Basic Helix-Loop-Helix Proteins / Q000235:genetics / Q000502:physiology*; D002940:Circadian Rhythm; D035264:Flowers / Q000235:genetics / Q000502:physiology*; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D014644:Genetic Variation; D018546:Hypocotyl / Q000502:physiology; D009154:Mutation; D010455:Peptides / Q000737:chemistry; D010641:Phenotype; D017440:Photoperiod; D013696:Temperature; D014157:Transcription Factors / Q000235:genetics / Q000502:physiology*; D019076:Transgenes
chemical_list: D029681:Arabidopsis Proteins; D051792:Basic Helix-Loop-Helix Proteins; D010455:Peptides; D014157:Transcription Factors; C432430:At2g25930 protein, Arabidopsis; C459466:PIF4 protein, Arabidopsis; C097188:polyglutamine