Cytokinin response factor 6 represses cytokinin-associated genes during oxidative stress Journal Article

Author(s): Zwack, Paul J; De Clercq, Inge; Howton, Timothy C; Hallmark, H Tucker; Hurny, Andrej; Keshishian, Erika A; Parish, Alyssa M; Benková, Eva; Mukhtar, M Shahid; Van Breusegem, Frank; Rashotte, Aaron M
Article Title: Cytokinin response factor 6 represses cytokinin-associated genes during oxidative stress
Affiliation IST Austria
Abstract: Cytokinin is a phytohormone that is well known for its roles in numerous plant growth and developmental processes, yet it has also been linked to abiotic stress response in a less defined manner. Arabidopsis (Arabidopsis thaliana) Cytokinin Response Factor 6 (CRF6) is a cytokinin-responsive AP2/ERF-family transcription factor that, through the cytokinin signaling pathway, plays a key role in the inhibition of dark-induced senescence. CRF6 expression is also induced by oxidative stress, and here we show a novel function for CRF6 in relation to oxidative stress and identify downstream transcriptional targets of CRF6 that are repressed in response to oxidative stress. Analysis of transcriptomic changes in wild-type and crf6 mutant plants treated with H2O2 identified CRF6-dependent differentially expressed transcripts, many of which were repressed rather than induced. Moreover, many repressed genes also show decreased expression in 35S:CRF6 overexpressing plants. Together, these findings suggest that CRF6 functions largely as a transcriptional repressor. Interestingly, among the H2O2 repressed CRF6-dependent transcripts was a set of five genes associated with cytokinin processes: (signaling) ARR6, ARR9, ARR11, (biosynthesis) LOG7, and (transport) ABCG14. We have examined mutants of these cytokinin-associated target genes to reveal novel connections to oxidative stress. Further examination of CRF6-DNA interactions indicated that CRF6 may regulate its targets both directly and indirectly. Together, this shows that CRF6 functions during oxidative stress as a negative regulator to control this cytokinin-associated module of CRF6- dependent genes and establishes a novel connection between cytokinin and oxidative stress response.
Journal Title: Plant Physiology
Volume: 172
Issue 2
ISSN: 1532-2548
Publisher: American Society of Plant Biologists  
Date Published: 2016-10-02
Start Page: 1249
End Page: 1258
Copyright Statement: Copyright © 2016 American Society of Plant Biologists. All rights reserved.
DOI: 10.1104/pp.16.00415
Notes: This work was financially supported by the following: The Alabama Agricultural Experiment Station HATCH grants 370222-310010-2055 and 370225-310006-2055 for funding to P.J.Z., E.A.K, A.M.P., and A.M.R. P.J.Z. and E.A.K were supported by an Auburn University Cellular and Molecular Biosciences Research Fellowship. I.D.C. is a postdoctoral fellow of the Research Foundation Flanders (FWO) (FWO/PDO14/043) and is also supported by FWO travel grant 12N2415N. F.V.B. was supported by grants from the Interuniversity Attraction Poles Programme (IUAP P7/29 MARS) initiated by the Belgian Science Policy Office and Ghent University (Multidisciplinary Research Partnership Biotechnology for a Sustainable Economy, grant 01MRB510W).
Open access: yes (OA journal)