supported by Key Basic Research Program (973) grant no: 2006CB101905 (to YL) and National Natural Science Foundation of China (NSFC) grants no. 30600095 (to MRD) and 30325012 (to XDS). Funding to pay the Open Access publication charge was provided by Peking University, P.R. China. Conﬂict of interest statement. None declared REFERENCES 1. Ulker,B. and Somssich,I.E. (2004) WRKY transcription factors: from DNA binding towards biological function. Curr. Opin. Plant Biol., 7, 491–498. 2. Zhang,Y. and Wang,L. (2005) The WRKY transcription factor superfamily: its origin in eukaryotes and expansion in plants. BMC Evol. Biol., 5, 1. 3. Chen,C. and Chen,Z. (2002) Potentiation of developmentally regulated plant defense response by AtWRKY18, a pathogen- induced Arabidopsis transcription factor. Plant Physiol., 129, 706–716. 4. Robatzek,S. and Somssich,I.E. (2002) Targets of AtWRKY6 regulation during plant senescence and pathogen defense. Genes Dev., 16, 1139–1149. 5. 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