David E. L.
Paul R. J.
1Unit of Mycology, Bacteriology and Nematology, Scottish Crop Research Institute, Invergowrie, Dundee, DD2 5DA, U.K.; 2Unit of Applied Genetics, Scottish Crop Research Institute, Invergowrie, Dundee, DD2 5DA, U.K.; 3Department of Biosciences, Division of Genetics, Box 56, FIN.00014, University of Finland, Helsinki
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Accepted 6 July 2000.
A potato gene encoding a putative WRKY protein was isolated from a cDNA library enriched by suppression subtractive hybridization for sequences upregulated 1 h post-inoculation with Erwinia carotovora subsp. atroseptica. The cDNA encodes a putative polypeptide of 172 amino acids, containing a single WRKY domain with a zinc finger motif and preceded by a potential nuclear localization site. St-WRKY1 was strongly upregulated in compatible, but only weakly in incompatible, interactions with Phytophthora infestans where, in all cases, it was coregulated with class I endochitinase, associating its expression with a known defense response. Whereas St-WRKY1 was strongly induced by E. carotovora culture filtrate (CF), confirming it to be an elicitor-induced gene, no such induction was detected after treatment with salicylic acid, methyl jasmonate, ethylene, or wounding. St-WRKY1 was upregulated by treatment of potato leaves with CFs from recombinant Escherichia coli containing plasmids expressing E. carotovora pectate lyase genes pelB and pelD, suggesting that either proteins encoded by these genes, or oligogalacturonides generated by their activity, elicit a potato defense pathway associated with St-WRKY1.
© 2000 The American Phytopathological Society