Fig. 6: UmCAPE-La enhances plant susceptibility by suppressing plant response.
From: Ustilago maydis PR-1-like protein has evolved two distinct domains for dual virulence activities
a, c Relative expression of maize PR genes at early infection. Maize seedlings inoculated with (a) SG200 and ΔΔpr-1lab without any peptides, or (c) ΔΔpr-1lab with 0.2 µM synthetic peptide CAPE-La (PPGNYIGKFKENVSPN). RNAs prepared from infected leaves harvested at indicated time point were subjected to qRT-PCR analysis. Expression levels of PR genes were normalized to the GAPDH expression. The normalized PR gene expression in (a) SG200 or (c) ΔΔpr-1lab was set to 1. Values represent mean ± sd of three independent infections. Significant differences between two samples were determined by a two-tailed unpaired Student’s t test (*P < 0.05; **P < 0.01; ***P < 0.001). PR1 (NM001147273); PR2 (HM021761); PR5 (U82201). b UmCAPE-La enhances the ΔΔpr-1lab virulence. Maize seedlings were inoculated with ΔΔpr-1lab along with 0.2 µM CAPE-La or ZmCAPE (from ZmPRB1-3). Disease symptoms were scored at 12 dpi. Total numbers of infected plants and the average DI determined from three independent infections are indicated above the respective columns. Statistical significance relative to the mock control were assessed using a two-tailed unpaired Student’s t test. d U. maydis-delivered ZmCAPEs suppress fungal virulence. Δpr-1la_PR-1La(CAPE-Lb) and Δpr-1la_PR-1La(ZmCAPE): Δpr-1la expressed the PR-1La mutant proteins carrying UmCAPE-Lb (PAGNVEGLFDAQVPAKVQPTPRLRSSCSANERHGS) or ZmCAPE peptides under the control of PR-1La promoter. The indicated strains were inoculated into maize seedlings. A description of each disease category is provided in the Method section. The average DI values determined from at least three independent infections are shown. Significant differences between SG200 and the indicated strains were determined by a two-tailed unpaired Student’s t test. Δpr-1la_PR-1La(CAPE-Lb) showed no statistically significant (ns) differences compared to the indicated strains. e UmCAPE-La mitigates the effect of ZmCAPE on fungal virulence. Maize seedlings were inoculated with Δpr-1la_PR-1La(ZmCAPE) along with 0.5 µM of CAPE-La, the scrambled peptide of CAPE-La (YFSKNIKNPPVEGNGP), or water (mock). The average DI values determined from three independent infections are shown. **P < 0.01 denotes significant difference between the CAPE-La and mock inoculation, determined by a two-tailed unpaired Student’s t test. Source data are provided as a Source Data file.
