Signaling Pathways That Regulate the Enhanced Disease….pdfVIP

MPMI Vol. 21, No. 10, 2008, pp. 1285–1296. doi:10.1094 / MPMI -21-10-1285. © 2008 The American Phytopathological Society Signaling Pathways That Regulate the Enhanced Disease Resistance of Arabidopsis “Defense, No Death” Mutants 1 1 2 3 3 3 Ruth K. Genger, Grace I. Jurkowski, John M. McDowell, Hua Lu, Ho Won Jung, Jean T. Greenberg, and Andrew F. Bent1 1Department of Plant Pathology, University of Wisconsin-Madison, Madison, WI 53706, U.S.A.; 2 Department of Plant Pathology, Physiology and Weed Science, Virginia Tech, Blacksburg, VA 24061, U.S.A.; 3 Department of Molecular Genetics and Cell Biology, University of Chicago, Chicago, IL 60637, U.S.A. Submitted 11 February 2008. Accepted 22 May 2008. Arabidopsis dnd1 and dnd2 mutants lack cyclic nucleotide- 2003). This “gene-for-gene” recognition rapidly induces an gated ion channel proteins and carry out avirulence or re- array of host defense responses, through signaling pathways sistance gene–mediated defense with a greatly reduced that include cellular ion fluxes, production of reactive oxygen hypersensitive response (HR). They also exhibit elevated intermediates, mitogen-activated protein kinase cascades, and broad-spectrum disease resistance and constitutively ele- accumulation of salicylic acid (SA), with contributions from vated salicylic acid (SA) levels. We examined the contribu- many signaling proteins (Glazebrook 2005; Hammond-Kosack tions of NPR1, SID2 (EDS16), NDR1, and EIN2 to dnd and Parker 2003; Jones and Dangl 2006; Nimchuk et al. 2003). phenotypes. Mutations that affect SA accumulation or sig-