Balanced Nuclear and Cytoplasmic Activities of EDS1 Are Required for a Complete Plant Innate Immune Response (original) (raw)
Figure 6
Nuclear release of EDS1-YFP-GR by Dexamethasone (Dex) treatment leads to protein accumulation in nuclei and enhanced disease resistance.
(A) Leaves of 4-week-old plants were pre-treated with Dex (+) or mock solution (−) and spray-inoculated with buffer (−) or Pst DC3000 AvrRps4 (+) and protein samples prepared 8 h post inoculation, as indicated. Western blot shows EDS1 protein levels in total, nuclei-depleted and nuclei-enriched fractions in transgenic lines #1 and #4 expressing the EDS1-YFP-GR fusion protein. Ponceau S staining of the membrane shows equal loading. PEPC and Histone H3 signals were used, respectively, as cytosolic and nuclear marker. (B) Confocal images showing EDS1-YFP-GR subcellular distribution in a representative transgenic line with or without Dex treatment 13 h after Dex treatment. Bar is 30 µm. (C) Untreated (white bars) or Dex-pretreated (5 h, grey bars) 4-week-old plants of the indicated genotypes were spray-inoculated with avirulent Pst DC3000 AvrRps4 and bacterial titers determined 4 d post inoculation. Bars represent means of 4 replicates ± standard error. ** p value <0.001; * p value <0.05. (D) Untreated or Dex-pretreated (5 h) 2-week-old plants were spray-inoculated with a spore suspension of avirulent H. arabidopsidis isolate Noco2. Leaves were stained with lactophenol trypan blue 7 d post inoculation to visualize pathogen growth and host cell death. h: hyphae; HR: hypersensitive response; eHR: expanded HR. Bar is 500 µm. (E) Untreated (white bars) or Dex-pretreated (5 h, grey bars) 4-week-old plants were spray-inoculated with virulent Pst DC3000 bacterial suspension and bacterial titers determined 4 d post inoculation. Bars represent means of 4 replicates ± standard error. ** p value <0.001; * p value <0.05. Results of the bacterial and oomycete infection assays are representative of three independent experiments.