title: Soluble carbohydrates regulate auxin biosynthesis via PIF proteins in Arabidopsis.
abstract: Plants are necessarily highly competitive and have finely tuned mechanisms to adjust growth and development in accordance with opportunities and limitations in their environment. Sugars from photosynthesis form an integral part of this growth control process, acting as both an energy source and as signaling molecules in areas targeted for growth. The plant hormone auxin similarly functions as a signaling molecule and a driver of growth and developmental processes. Here, we show that not only do the two act in concert but that auxin metabolism is itself regulated by the availability of free sugars. The regulation of the biosynthesis and degradation of the main auxin, indole-3-acetic acid (IAA), by sugars requires changes in the expression of multiple genes and metabolites linked to several IAA biosynthetic pathways. The induction also involves members of the recently described central regulator PHYTOCHROME-INTERACTING FACTOR transcription factor family. Linking these three known regulators of growth provides a model for the dynamic coordination of responses to a changing environment.
authors.affiliation: Umeå Plant Science Centre, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, SE-901 83 Umea, Sweden.
authors.forename: Ilkka
authors.initials: I
authors.lastname: Sairanen
authors.forename: Ondřej
authors.initials: O
authors.lastname: Novák
authors.forename: Aleš
authors.initials: A
authors.lastname: Pěnčík
authors.forename: Yoshihisa
authors.initials: Y
authors.lastname: Ikeda
authors.forename: Brian
authors.initials: B
authors.lastname: Jones
authors.forename: Göran
authors.initials: G
authors.lastname: Sandberg
authors.forename: Karin
authors.initials: K
authors.lastname: Ljung
mesh_terms: D017360:Arabidopsis / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D051792:Basic Helix-Loop-Helix Proteins / Q000235:genetics / Q000378:metabolism*; D005947:Glucose / Q000494:pharmacology; D007210:Indoleacetic Acids / Q000378:metabolism*
chemical_list: D029681:Arabidopsis Proteins; D051792:Basic Helix-Loop-Helix Proteins; D005947:Glucose; D007210:Indoleacetic Acids; C508068:At2g20180 protein, Arabidopsis; C116162:PIF3 protein, Arabidopsis; C459466:PIF4 protein, Arabidopsis; C497729:PIF5 protein, Arabidopsis