Expression profiling of the host response to bacterial infection: the transition from basal to induced defence responses in RPM1-mediated resistance.
Changes in transcription in leaves of Arabidopsis thaliana were characterised following challenge with strains of Pseudomonas syringae pv. tomato DC3000 allowing differentiation of basal resistance (hrpA mutants), gene-specific resistance (RPM1-specified interactions) and susceptibility (wild-type pathogen). In planta avirulence gene induction, changes in host [Ca2+]cyt and leaf collapse were used to delineate the transition from infection to induced resistance. The plant responds rapidly, dynamically and discriminately to infection by phytopathogenic bacteria. Within the first 2 h host transcriptional changes are common to all challenges indicating that Type III effector function does not contribute to early events in host transcriptome re-programming. The timing of induction for specific transcripts was reproducible, hierarchical and modulated at least in part through EDS1 function. R gene-specific transcripts were not observed until 3 h after inoculation. Intriguingly, the R gene-specific response proteins are expected to localise to diverse cellular addresses indicative of a global impact on cellular homeostasis. The altered transcriptional response rapidly manifests into initial symptoms of leaf collapse within 2 h, although establishment of the full macroscopic HR occurs significantly later.
de Torres
Marta
M
Department of Agricultural Sciences, Imperial College at Wye, Wye, Kent TN25 5AH, UK.
Sanchez
Pedro
P
Fernandez-Delmond
Isabelle
I
Grant
Murray
M
D017360:Arabidopsis / Q000235:genetics* / Q000382:microbiology; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism; D001419:Bacteria / Q000254:growth & development* / Q000472:pathogenicity; D002118:Calcium / Q000378:metabolism; D018076:DNA, Complementary / Q000235:genetics; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D007113:Immunity, Innate / Q000235:genetics* / Q000502:physiology; D010935:Plant Diseases / Q000235:genetics* / Q000382:microbiology; D012150:Polymorphism, Restriction Fragment Length; D018749:RNA, Plant / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction / Q000235:genetics / Q000502:physiology; D015533:Transcriptional Activation
D029681:Arabidopsis Proteins; D018076:DNA, Complementary; D004268:DNA-Binding Proteins; C118837:EDS1 protein, Arabidopsis; D018749:RNA, Plant; C095014:RPM1 protein, Arabidopsis; D002118:Calcium