Brassinosteroids participate in the control of basal and acquired freezing tolerance of plants Journal Article

Author(s): Eremina, Marina; Unterholzner, Simon J; Rathnayake, Ajith I; Castellanos, Marcos; Khan, Mamoona; Kügler, Karl G; May, Sean T; Mayer, Klaus F; Rozhon, Wilfried M; Poppenberger, Brigitte
Article Title: Brassinosteroids participate in the control of basal and acquired freezing tolerance of plants
Affiliation IST Austria
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 post-translational 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.
Keywords: Brassinosteroid; CBF1; CBFs; CESTA; Cold responses
Journal Title: PNAS
Volume: 113
Issue 40
ISSN: 1091-6490
Publisher: National Academy of Sciences  
Date Published: 2016-10-04
Start Page: E5982
End Page: E5991
DOI: 10.1073/pnas.1611477113
Notes: We thank Joanne Chory for seeds of the bee1 bee2 bee3, bes1-D, and bzr1-1D mutants and the 35S:BRI1-GFP line; Irene Ziegler, Clarissa Fahrig, and Renata Milcevicova for technical assistance; and the horticultural staff of the TUMs Gewächshauslaborzentrum Dürnast for plant care. This work was supported by funds from the Austrian Science Fund (Project P22734 to B.P.), the Deutsche Forschungsgemeinschaft (Project PO1640/4 to B.P. and SFB924 to B.P. and K.F.X.M.), and a TUM doctoral fellowship (to M.E.). M.E. and S.J.U. were members of the TUM graduate school.
Open access: yes (repository)