We carried out transcriptional profiling analysis in 10-d-old Arabidopsis thaliana seedlings treated with oligogalacturonides （OGs）, oligosaccharides derived from the plant cell wall, or the bacterial flagellin pept...We carried out transcriptional profiling analysis in 10-d-old Arabidopsis thaliana seedlings treated with oligogalacturonides （OGs）, oligosaccharides derived from the plant cell wall, or the bacterial flagellin peptide Fig22, general elicitors of the basal defense response in plants. Although detected by different receptors, both OGs and Fig22 trigger a fast and transient response that is both similar and comprehensive, and characterized by activation of early stages of multiple defense signaling pathways, particularly JA-associated processes. However, the response to Fig22 is stronger in both the number of genes differentially expressed and the amplitude of change. The magnitude of induction of individual genes is in both cases dose-dependent, but, even at very high concentrations, OGs do not induce a response that is as comprehensive as that seen with Fig22. While high doses of either microbe-associated molecular pattern （MAMP） elicit a late response that includes activation of senescence processes, SA-dependent secretory pathway genes and PR1 expres- sion are substantially induced only by Fig22. These results suggest a lower threshold for activation of early responses than for sustained or SA-mediated late defenses. Expression patterns of amino-cyclopropane-carboxylate synthase genes also implicate ethylene biosynthesis in regulation of the late innate immune response.展开更多
文摘We carried out transcriptional profiling analysis in 10-d-old Arabidopsis thaliana seedlings treated with oligogalacturonides （OGs）, oligosaccharides derived from the plant cell wall, or the bacterial flagellin peptide Fig22, general elicitors of the basal defense response in plants. Although detected by different receptors, both OGs and Fig22 trigger a fast and transient response that is both similar and comprehensive, and characterized by activation of early stages of multiple defense signaling pathways, particularly JA-associated processes. However, the response to Fig22 is stronger in both the number of genes differentially expressed and the amplitude of change. The magnitude of induction of individual genes is in both cases dose-dependent, but, even at very high concentrations, OGs do not induce a response that is as comprehensive as that seen with Fig22. While high doses of either microbe-associated molecular pattern （MAMP） elicit a late response that includes activation of senescence processes, SA-dependent secretory pathway genes and PR1 expres- sion are substantially induced only by Fig22. These results suggest a lower threshold for activation of early responses than for sustained or SA-mediated late defenses. Expression patterns of amino-cyclopropane-carboxylate synthase genes also implicate ethylene biosynthesis in regulation of the late innate immune response.
