CHARACTERIZATION OF EARLY INDUCED GENES IN ARABIDOPSIS-THALIANA RESPONDING TO BACTERIAL INOCULATION - IDENTIFICATION OF CENTRIN AND OF A NOVEL PROTEIN WITH 2 REGIONS RELATED TO KINASE DOMAINS

The early response to bacterial inoculation has been investigated and two Arabidopsis genes, ap3,3a and ap4,3a have been characterized. The AP3,3A protein showed high identity to centrin, a ubiquitous cytoskele tal protein first identified in unicellular green alga, Amino-acid seq uence analyses of the AP4,3A protein indicates that the second gene ch aracterized encodes an unusual protein with two putative kinase domain s. Expression of ap3,3a and ap4.3a was rapidly induced after pathogen inoculation. A role of ap3.3a in plant defense could be postulated bas ed on its preferential induction during the incompatible interactions analyzed. In contrast, activation of ap4.3a was not specific and could be related to a more general stress response. (C) 1998 Federation of European Biochemical Societies.