Fig. 4

The septin genes are required for the full virulence. a Symptom phenotype on Nicotiana benthamiana. One-month-old tobacco seedlings were immersed in conidial suspension (10⁶ conidia/mL) of each strain for 10 min. Sterile distilled water was used as control (CK). After inoculation, all seedlings were replanted in soil and incubated in a greenhouse for 35 days at 25 °C. b Column diagram showing disease index at 35 days post-inoculation (dpi). The disease was scored on a scale of 0–4. 0, no wilting; 1, yellowing or wilting of < 2 leaves; 2, yellowing or wilting of one-fourth leaves; 3, yellowing or wilting of two-thirds leaves; and 4, more than 85% of the leaves wilted or the whole plant died. Bars represent the percentages of plants under each scale. The experiments were repeated three times with similar results (**, P < 0.01). c Column diagram showing survival rates of tobacco plants. The data were determined at 35 dpi. Error bars represent standard deviation based on three independent experiment replicates (**, P < 0.01). d Detection of the pathogen at the stem-root junction of inoculated plants at 35 dpi. e Fungal biomass detected by qRCR at 5 dpi. Error bars represent standard deviation based on four independent technical replicates (**, P < 0.01). f The ΔΔCt values of qPCR. Error bars represent standard deviation based on four independent technical replicates (**, P < 0.01; *, P < 0.05)