Jose J. Rodríguez-Herva,1
Pablo Rodríguez-Palenzuela,1 and
1Centro de Biotecnología y Genómica de Plantas (CBGP), Universidad Politécnica de Madrid-Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria, Pozuelo de Alarcón, Madrid, Spain; 2The James Hutton Institute, Invergowrie, Dundee DD25DA, Scotland, U.K.
Go to article:
Accepted 18 December 2011.
Antimicrobial peptides constitute an important factor in the defense of plants against pathogens, and bacterial resistance to these peptides have previously been shown to be an important virulence factor in Dickeya dadantii, the causal agent of soft-rot disease of vegetables. In order to understand the bacterial response to antimicrobial peptides, a transcriptional microarray analysis was performed upon treatment with sub-lethal concentration of thionins, a widespread plant peptide. In all, 36 genes were found to be overexpressed, and were classified according to their deduced function as i) transcriptional regulators, ii) transport, and iii) modification of the bacterial membrane. One gene encoding a uricase was found to be repressed. The majority of these genes are known to be under the control of the PhoP/PhoQ system. Five genes representing the different functions induced were selected for further analysis. The results obtained indicate that the presence of antimicrobial peptides induces a complex response which includes peptide-specific elements and general stress-response elements contributing differentially to the virulence in different hosts.
© 2012 The American Phytopathological Society