Transcriptional analysis of the sweet orange interaction with the citrus canker pathogens

ABSTRACT: We have used the citrus GeneChip array (GPL5731) to survey the transcription profiles of sweet orange in response to the bacterial pathogens Xanthomonas axonopodis pv. citri (Xac) and Xanthomonas axonopodis pv. aurantifolii (Xaa). Xac is the causal agent of the citrus canker disease on a wide range of citrus species, including sweet oranges (Citrus sinensis). On the other hand, Xaa is pathogenic to Mexican lime (Citrus aurantifolia) only, and in sweet orange it triggers a defense response. In order to identify the genes induced during the defense response (Xaa-responsive genes) or citrus canker development (Xac-responsive genes), we conducted microarrays hybridization experiments at 6 and 48 hours after bacterial infiltration (habi). The analysis revealed that genes commonly modulated by Xac and Xaa are associated with basal defenses normally triggered by pathogen-associated molecular patterns, including those involved in reactive oxygen species production and lignification. Significantly, Xac-infected leaves showed considerable changes in the transcriptional profiles of defense-, cell wall-, vesicle trafficking- and cell growth-related genes between 6 and 48 habi. This is consistent with the notion that Xac suppresses host defenses near the beginning of the infection and simultaneously changes the physiological status of the host to promote cell enlargement and division. Finally, Xaa triggered a MAP kinase signaling pathway involving WRKY and ethylene-responsive transcriptional factors known to activate downstream defense genes. Keywords: Comprehensive transcriptional analysis of the Citrus-Xanthomonas interaction Adult leaves of sweet orange were infiltrated with the bacterial suspensions or water (mock control). Two stages were selected after bacterial infiltration for RNA extraction and hybridization on Affymetrix microarrays. In total, these experiments consist of two biological replicates of six samples: water-infiltrated leaves, Xaa-infiltrated leaves and Xac-infiltrated leaves, at both 6 and 48 (habi).

ORGANISM(S): Citrus sinensis

SUBMITTER: C Benedetti 

PROVIDER: E-GEOD-10798 | biostudies-arrayexpress |

REPOSITORIES: biostudies-arrayexpress