title: Strigolactone promotes degradation of DWARF14, an α/β hydrolase essential for strigolactone signaling in Arabidopsis.
abstract: Strigolactones (SLs) are phytohormones that play a central role in regulating shoot branching. SL perception and signaling involves the F-box protein MAX2 and the hydrolase DWARF14 (D14), proposed to act as an SL receptor. We used strong loss-of-function alleles of the Arabidopsis thaliana D14 gene to characterize D14 function from early axillary bud development through to lateral shoot outgrowth and demonstrated a role of this gene in the control of flowering time. Our data show that D14 distribution in vivo overlaps with that reported for MAX2 at both the tissue and subcellular levels, allowing physical interactions between these proteins. Our grafting studies indicate that neither D14 mRNA nor the protein move over a long range upwards in the plant. Like MAX2, D14 is required locally in the aerial part of the plant to suppress shoot branching. We also identified a mechanism of SL-induced, MAX2-dependent proteasome-mediated degradation of D14. This negative feedback loop would cause a substantial drop in SL perception, which would effectively limit SL signaling duration and intensity.
authors.affiliation: Plant Molecular Genetics Department, Centro Nacional de Biotecnología/Consejo Superior de Investigaciones Científicas, Campus Universidad Autónoma de Madrid, 28049 Madrid, Spain.
authors.forename: Florian
authors.initials: F
authors.lastname: Chevalier
authors.forename: Kaisa
authors.initials: K
authors.lastname: Nieminen
authors.forename: Juan Carlos
authors.initials: JC
authors.lastname: Sánchez-Ferrero
authors.forename: María Luisa
authors.initials: ML
authors.lastname: Rodríguez
authors.forename: Mónica
authors.initials: M
authors.lastname: Chagoyen
authors.forename: Christian S
authors.initials: CS
authors.lastname: Hardtke
authors.forename: Pilar
authors.initials: P
authors.lastname: Cubas
mesh_terms: D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000254:growth & development / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D006867:Hydrolases / Q000378:metabolism*; D007783:Lactones / Q000378:metabolism*; D008969:Molecular Sequence Data; D059748:Proteolysis; D017386:Sequence Homology, Amino Acid; D015398:Signal Transduction; D014158:Transcription, Genetic
chemical_list: D029681:Arabidopsis Proteins; D007783:Lactones; D006867:Hydrolases