Article Figures & Data
Figures
- Figure 1.
Expression pattern of SDG8p::GUS in transgenic plants. A, Eight-day-old seedling. B, Closeup of the shoot tip of an 8-d-old seedling. C, Part of the leaf margin. The inset shows a whole leaf. D, Base of shoot branches and cauline leaf petiole. E, Open flower. F, Young silique. G, Mature leaf wounded immediately prior to GUS staining. H, Leaf inoculated with B. cinerea at 3 dpi before (left) and after (right) GUS staining. I, Leaf inoculated with A. brassicicola at 5 dpi before (left) and after (right) GUS staining. J, Relative level of endogenous SDG8 expression after B. cinerea (gray bars) or mock (white bars) inoculation. Data represent means ± sd of triplicate determinations. Asterisks indicate significant differences between Col and sdg8-1 at P < 0.05 (two-sided t test). Similar results were obtained in two independent experiments (Supplemental Table S1).
- Figure 2.
Comparison of pathogen-responsive phenotypes between mutant sdg8 and wild-type Col plants. A, Plant disease symptoms observed at 3 dpi on leaves inoculated with B. cinerea. Mock inoculation is shown as a control. White arrows indicate small lesions caused by B. cinerea on wild-type Col leaves. Note that more severe lesions occur in both sdg8-1 and sdg8-2 mutants. B, Mean leaf lesion diameter at 3 dpi with B. cinerea (n ≥ 20; ±se). C, Visualization of fungal growth and cell death in Col and sdg8-1 leaves after trypan blue staining at 3 dpi with B. cinerea. D, Quantification of in planta growth of B. cinerea. qPCR was used to analyze the relative genomic DNA level of B. cinerea CUTINASE A compared with Arabidopsis ACTIN2 (Bo cut-A/At ACT). Data represent means ± sd of triplicate determinations. E, Plant disease symptoms observed at 5 dpi on leaves inoculated with A. brassicicola. White arrows indicate small lesions observed on Col leaves. F, Mean leaf lesion diameter at 2 and 5 dpi with A. brassicicola (n ≥ 20; ±se). G, Quantification of in planta growth of A. brassicicola. qPCR was used to analyze the relative genomic DNA level of A. brassicicola CUTINASE compared with Arabidopsis ACTIN2 (Alt cutab1/At ACT). Data represent means ± sd of triplicate determinations. Asterisks indicate significant differences between Col and sdg8-1 at P < 0.05 (two-sided t test).
- Figure 3.
Comparison of camalexin accumulation and defense marker gene expression in response to pathogen infection in mutant sdg8-1 and wild-type Col plants. A, Relative levels of camalexin in response to A. brassicicola infection in sdg8-1 and Col plants. Camalexin values are presented relative to average wild-type levels at time point 0 (set as 1). Data represent means ± se of triplicate determinations. B, Simplified model for the regulation of plant defense networks in response to necrotrophic pathogen infection. Genes (in italics) involved in the JA and ET signaling pathways, as well as MAPK kinase genes and their corresponding phosphorylation cascade (arrows with black heads), are defined in the text. Positive (arrows with white heads) and negative (bars) regulations are depicted. C, Relative expression levels of PDF1.2a and VSP2 in sdg8-1 and Col leaves in response to A. brassicicola inoculation. Gene expression values are presented relative to average wild-type levels at time point 0 (set as 1). Data represent means ± sd of triplicate determinations. Asterisks indicate significant differences between Col and sdg8-1 at P < 0.05 (two-sided t test). Similar results were obtained in two independent experiments (Supplemental Table S2).
- Figure 4.
Comparison of JA accumulation and expression of JA/ET-responsive genes in mutant sdg8-1 and wild-type Col plants. A, Endogenous JA levels were measured by UPLC-MS using sdg8-1 and Col leaves from plants inoculated with A. brassicicola. Data represent means ± sd of triplicate determinations. B, Relative expression levels of JA/ET pathway genes in sdg8-1 and Col leaves in response to treatment with exogenously applied MeJA. Gene expression values are presented relative to average wild-type levels at time point 0 (set as 1). Data represent means ± sd of triplicate determinations. Asterisks indicate significant differences between Col and sdg8-1 at P < 0.05 (two-sided t test). Similar results were obtained in two independent experiments (Supplemental Table S4).
- Figure 5.
Analysis of histone methylation at defense marker genes in response to pathogen infection in mutant sdg8-1 and wild-type Col plants. ChIP analysis was used to determine the relative levels of H3K36me3, H3K36me1, and H3K27me3 before (white bars) and 2 d after (black bars) A. brassicicola inoculation of 6-week-old Col and sdg8-1 plants at the indicated regions of PDF1.2a and VSP2. Data represent means ± sd of triplicate determinations. Similar results were obtained in two independent experiments (Supplemental Table S6). Amplified regions (named a–d) are indicated below each gene schematic, which is represented by a white box for the coding region and gray boxes for the 5′ and 3′ untranslated regions.
- Figure 6.
Expression and H3K36 methylation levels of MAPK kinase genes in response to pathogen infection in mutant sdg8-1 and wild-type Col plants. A and B, Relative expression levels of MKK3 and MKK5 after A. brassicicola inoculation and exogenous MeJA treatment. Gene expression values are presented relative to average wild-type levels at time point 0 (set as 1). Data represent means ± sd of triplicate determinations. Asterisks indicate significant differences between Col and sdg8-1 at P < 0.05 (two-sided t test). Similar results were obtained in two independent experiments (Supplemental Tables S2 and S4). C, Relative levels of H3K36me3 and H3K36me1 before (white bars) and 2 d after (black bars) A. brassicicola inoculation of 6-week-old Col and sdg8-1 plants at the indicated regions of MKK3 and MKK5. Data represent means ± sd of triplicate determinations. Similar results were obtained in two independent experiments (Supplemental Table S6). Amplified regions (named e–j) are indicated below each gene, which is represented by a white box for the coding region and gray boxes for the 5′ and 3′ untranslated regions.
Additional Files
Supplemental Data
Supplemental Figures and Tables
Files in this Data Supplement:
- Supplemental Data - Supplemental Figures 1-8
- Supplemental Data - Supplemental Tables I-VIII
