Figure 1.

Microscopy of trypan blue‐stained infection sites between different Arabidopsis genotypes and Magnaporthe oryzae (isolate TH6772) at 2 days post‐inoculation. (A) M. oryzae conidium (co) germination and appressorium (app) formation on Arabidopsis Col‐0 plants did not induce cellular defence responses. (B) Penetration by an M. oryzae invasive hypha (ih) from an appressorium into an epidermal cell of a pen2‐1 mutant, which subsequently underwent cell death, as evidenced by trypan blue staining (Keogh et al., 1980). (C) Quantitative assessment of single‐cell interaction sites on Arabidopsis wild‐type and mutant plants. Plants were grown with an 8‐h light period, at 22 °C and 65% relative humidity, and spray inoculated with M. oryzae isolate TH6772 (2.5 × 10⁵ conidia/mL, 5 weeks after sowing). Individual interaction sites were grouped into different classes (see text) and the frequency for each class is given as the mean plus standard deviation per leaf. At least eight leaves were analysed per genotype and 100 infection sites were inspected per leaf. Significant differences (P < 0.05) for each class on different genotypes were determined using one‐way analysis of variance and are indicated by different letters or numbers. Values excluded from statistical analysis because the normality test and/or equal variance test failed are indicated by #. The experiment was repeated once with a similar result.