Fig. 1.

Two Albugo species compromise plant immunity and enable sporulation of Phytophthora infestans. a–f Albugo species compromise Arabidopsis immunity to P. infestans. Water-sprayed (a, d), Albugo laibachii Nc14-sprayed (b, e), and Albugo candida AcEx1-sprayed (c, f) Col-0 leaves (13 days post inoculation (dpi)) were drop inoculated with 100 μL of 5 × 10⁴ spores per mL P. infestans 88069td. a–c Photographs taken 3 dpi with P. infestans. Scale bar: 5 mm. Arrows denote P. infestans sporulation. d–f Fluorescence microscopy of the adaxial surface of the leaf. Red fluorescence denotes P. infestans growth. Scale bar: 200 μm. Results shown are representative of three independent experiments. g–i A. candida compromises Brassica juncea immunity to P. infestans. g Water-sprayed (left) and A. candida Ac2V-infected (right) B. juncea leaves (12 dpi) were drop inoculated with several 250 μL drops of 4 × 10⁴ spores per mL P. infestans 88069td. Photographs were taken 3 dpi with P. infestans. Scale bar: 5 mm. Arrows denote P. infestans sporulation. h, i Fluorescence microscopy of the adaxial surface of water-sprayed (h) and Ac2V-infected (i) leaves. Red fluorescence denotes P. infestans growth. Scale bar: 200 μm. Results shown are representative of three independent experiments