The MKK2 pathway mediates cold and salt stress signaling in Arabidopsis

Author(s)
Markus Teige, Elisabeth Scheikl, Thomas Eulgem, Robert Dóczi, Kazuya Ichimura, Kazuo Shinozaki, Jeffery L Dangl, Heribert Hirt
Abstract

The Arabidopsis mitogen-activated protein kinase (MAPK) kinase 2 (MKK2) and the downstream MAPKs MPK4 and MPK6 were isolated by functional complementation of osmosensitive yeast mutants. In Arabidopsis protoplasts, MKK2 was specifically activated by cold and salt stress and by the stress-induced MAPK kinase kinase MEKK1. Yeast two-hybrid, in vitro, and in vivo protein kinase assays revealed that MKK2 directly targets MPK4 and MPK6. Accordingly, plants overexpressing MKK2 exhibited constitutive MPK4 and MPK6 activity, constitutively upregulated expression of stress-induced marker genes, and increased freezing and salt tolerance. In contrast, mkk2 null plants were impaired in MPK4 and MPK6 activation and were hypersensitive to salt and cold stress. Full genome transcriptome analysis of MKK2-overexpressing plants demonstrated altered expression of 152 genes involved in transcriptional regulation, signal transduction, cellular defense, and stress metabolism. These data identify a MAP kinase signaling cascade mediating cold and salt stress tolerance in plants.

Organisation(s)
External organisation(s)
University of North Carolina at Chapel Hill, Ulmer Fundamental Symmetries Laboratory, Universität Wien, Österreichische Akademie der Wissenschaften (ÖAW)
Journal
Molecular Cell
Volume
15
Pages
141-152
No. of pages
12
ISSN
1097-2765
DOI
https://doi.org/10.1016/j.molcel.2004.06.023
Publication date
2004
Peer reviewed
Yes
Austrian Fields of Science 2012
1060 Biology
Portal url
https://ucris.univie.ac.at/portal/en/publications/the-mkk2-pathway-mediates-cold-and-salt-stress-signaling-in-arabidopsis(ef23de38-0fb9-42f3-9407-f282dc6437b8).html