Calmodulin-binding transcription activator (CAMTA) 3 mediates biotic defense responses in Arabidopsis

Galon, Yael; Nave, Roy; Boyce, Joy M.; Nachmias, Dikla; Knight, Marc R.; Fromm, Hillel

doi:10.1016/j.febslet.2008.02.037

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Volume 582, Issue 6 , Pages 943-948, 19 March 2008

Calmodulin-binding transcription activator (CAMTA) 3 mediates biotic defense responses in Arabidopsis

Edited by Michael R. Sussman

Yael Galon
- Department of Plant Sciences, Faculty of Life Sciences, Tel Aviv University, Tel Aviv 69978, Israel
- These authors contributed equally to this work.
Roy Nave
- Department of Plant Sciences, Faculty of Life Sciences, Tel Aviv University, Tel Aviv 69978, Israel
- These authors contributed equally to this work.
Joy M. Boyce
- Department of Plant Sciences, University of Oxford, South Parks Road, Oxford OX1 3RB, UK
- These authors contributed equally to this work.
Dikla Nachmias
- Department of Plant Sciences, Faculty of Life Sciences, Tel Aviv University, Tel Aviv 69978, Israel
Marc R. Knight
- Plant Stress Signalling Lab, Institute of Plant and Microbial Sciences, School of Biological and Biomedical Sciences, Durham University, South Road, Durham DH1 3LE, UK
Hillel Fromm
- Department of Plant Sciences, Faculty of Life Sciences, Tel Aviv University, Tel Aviv 69978, Israel
- Corresponding author. Fax: +972 3 6406816.

Received 18 January 2008; received in revised form 14 February 2008; accepted 15 February 2008. published online 25 February 2008.

Abstract

Calmodulin-binding transcription activator (CAMTA) 3 (also called SR1) is a calmodulin-binding transcription factor in Arabidopsis. Two homozygous T-DNA insertion mutants (camta3-1, camta3-2) showed enhanced spontaneous lesions. Transcriptome analysis of both mutants revealed 6 genes with attenuated expression and 99 genes with elevated expression. Of the latter, 32 genes are related to defense against pathogens (e.g. WRKY33, PR1 and chitinase). Propagation of a virulent strain of the bacterial pathogen Pseudomonas syringae and the fungal pathogen Botrytis cinerea were attenuated in both mutants. Moreover, both mutants accumulated high levels of H₂O₂. We suggest that CAMTA3 regulates the expression of a set of genes involved in biotic defense responses.

Abbreviations: CaM, calmodulin, CAMTA, CaM-binding transcription activator, DAB, 3-diaminobenzidine, LMM, lesion mimicking mutant, ROS, reactive oxygen species, TF, transcription factor, cfu, colony forming units