Fig. 3. CHUP1 and JAC1 regulate the ECR in a phototropin-independent manner.
a Levels of CHUP1 and HA-JAC1 proteins in the indicated Arabidopsis. Protein extracts were analyzed by immunoblot with anti-CHUP1 and anti-HA antibodies. CBB staining was used as a loading control. b, e Effects of CHUP1 and JAC1 on Cfio-induced ECR. Cfio was inoculated onto cotyledons of CHUP1ox and jac1, and the surface of the epidermis was observed. DW was spotted onto chup1, CHUP1-R4A&S12A&R20Aox lines, HA-JAC1ox, and jac1 as a control. The epidermal chloroplasts were visualized based on chlorophyll autofluorescence. The DIC images were captured by confocal microscopy at the indicated time point. Scale bar, 10 µm. c–e Quantification of ECR in CHUP1ox, chup1, HA-JAC1ox, jac1, and CHUP1-R4A&S12A&R20Aox plants. Cfio, Csia, and Corb (5 × 105 conidia/mL) were inoculated onto cotyledons of the indicated Arabidopsis and examined at 1, 2, and 3 dpi (c, e). For more fungal inoculum on the chup1 mutant, Cfio (1.5 × 106 conidia/mL) was inoculated (d). A total of 100 cells in contact with the melanized appressorium were observed. As a control, DW was spotted. f Cfio-induced ECR in phot2 and phot1 phot2 mutants. As a control, DW was spotted. The means and SE were calculated from three independent plants. Means not sharing the same letter are significantly different (P < 0.05, two-way ANOVA with Tukey’s HSD test). n.s. not significant.