Fig. 3.

Phytophthora parasitica H1111 is able to infect BY-2 cells. a Quantification of P. parasitica H1111 infections on BY-2 cells at 16 hpi (n = 3, 500 cells/sample). Cells that have been penetrated by Phytophthora hyphae were counted as infected. b–d Microscopic images of BY-2 cells penetrated by P. parasitica hyphae at 6 hpi (b), secondary infection at 16 hpi (c) and formation of sporangia at 48 hpi (d). Arrows point to the sites of penetration (b) or sporangia (d). Bars represent 100 μm. e Percentages of BY-2 and MsK8 cells in the cell suspension showing cell death at 16 hpi. Cell death was quantified by counting the cells stained with PI (as shown in the microscopic images) and the total number of cells (set at 100%). Bars in images represent 200 μm. f ROS production by MsK8 and BY-2 cells measured at different time points (X-axis) after inoculation with P. parasitica zoospores. ROS production was quantified by measuring the H₂O₂ concentration with the xylenol orange assay. Error bars represent standard deviation (n = 3)