title: Brassinosteroids participate in the control of basal and acquired freezing tolerance of plants.
abstract: Brassinosteroids (BRs) are growth-promoting plant hormones that play a role in abiotic stress responses, but molecular modes that enable this activity remain largely unknown. Here we show that BRs participate in the regulation of freezing tolerance. BR signaling-defective mutants of Arabidopsis thaliana were hypersensitive to freezing before and after cold acclimation. The constitutive activation of BR signaling, in contrast, enhanced freezing resistance. Evidence is provided that the BR-controlled basic helix-loop-helix transcription factor CESTA (CES) can contribute to the constitutive expression of the C-REPEAT/DEHYDRATION-RESPONSIVE ELEMENT BINDING FACTOR (CBF) transcriptional regulators that control cold responsive (COR) gene expression. In addition, CBF-independent classes of BR-regulated COR genes are identified that are regulated in a BR- and CES-dependent manner during cold acclimation. A model is presented in which BRs govern different cold-responsive transcriptional cascades through the posttranslational modification of CES and redundantly acting factors. This contributes to the basal resistance against freezing stress, but also to the further improvement of this resistance through cold acclimation.
authors.affiliation: Biotechnology of Horticultural Crops, Technische Universität München (TUM) School for Life Sciences Weihenstephan, TUM, D-85354 Freising, Germany.
authors.forename: Marina
authors.initials: M
authors.lastname: Eremina
authors.affiliation: Biotechnology of Horticultural Crops, Technische Universität München (TUM) School for Life Sciences Weihenstephan, TUM, D-85354 Freising, Germany.
authors.forename: Simon J
authors.initials: SJ
authors.lastname: Unterholzner
authors.affiliation: Biotechnology of Horticultural Crops, Technische Universität München (TUM) School for Life Sciences Weihenstephan, TUM, D-85354 Freising, Germany.
authors.forename: Ajith I
authors.initials: AI
authors.lastname: Rathnayake
authors.affiliation: Nottingham Arabidopsis Stock Centre, School of Biosciences, University of Nottingham, Loughborough LE12 5RD, United Kingdom.
authors.forename: Marcos
authors.initials: M
authors.lastname: Castellanos
authors.affiliation: Biotechnology of Horticultural Crops, Technische Universität München (TUM) School for Life Sciences Weihenstephan, TUM, D-85354 Freising, Germany.
authors.forename: Mamoona
authors.initials: M
authors.lastname: Khan
authors.affiliation: Plant Genome and Systems Biology, Helmholtz Center Munich, D-85764 Neuherberg, Germany.
authors.forename: Karl G
authors.initials: KG
authors.lastname: Kugler
authors.affiliation: Nottingham Arabidopsis Stock Centre, School of Biosciences, University of Nottingham, Loughborough LE12 5RD, United Kingdom.
authors.forename: Sean T
authors.initials: ST
authors.lastname: May
authors.affiliation: Plant Genome and Systems Biology, Helmholtz Center Munich, D-85764 Neuherberg, Germany; TUM School for Life Sciences Weihenstephan, TUM, D-85354 Freising, Germany.
authors.forename: Klaus F X
authors.initials: KF
authors.lastname: Mayer
authors.affiliation: Biotechnology of Horticultural Crops, Technische Universität München (TUM) School for Life Sciences Weihenstephan, TUM, D-85354 Freising, Germany.
authors.forename: Wilfried
authors.initials: W
authors.lastname: Rozhon
authors.affiliation: Biotechnology of Horticultural Crops, Technische Universität München (TUM) School for Life Sciences Weihenstephan, TUM, D-85354 Freising, Germany; brigitte.poppenberger@wzw.tum.de.
authors.forename: Brigitte
authors.initials: B
authors.lastname: Poppenberger
keywords: CBF1; CBFs; CESTA; brassinosteroid; cold responses