Fig. 2: The entry of HARP1 into plant cells is mediated by endocytosis.

The wounded Arabidopsis leaves were pretreated with DMSO (CK), A23, Wm and BFA before incubated with V-HARP1. a V-HARP1 signals were reduced in the leaves with A23 and Wm pretreatment. Scale bar: 200 µm. b Quantification of the fluorescent signal intensity (in arbitrary units, arb. units) of V-HARP1 in (a). Data are mean ± SEM (n = 7). Seven leaves from 4–5 independent plants were examined. Data are analyzed by one-way ANOVA with two-sided Dunnett’s post hoc test (n.s: not significant, ****p < 0.0001). c BFA pretreatment caused the aggregation of V-HARP1-located endosomes and the granulated V-HARP1 inside the pavement cells of the A23 and Wm pretreated leaves were disappeared. The arrow indicates the aggregation of V-HARP1-located endosomes. FM4-64 was used to trace internalized endosomes. Scale bar: 10 µm. d Fluorescence intensity (in arbitrary units, arb. units) in cross-section [dotted line in (c)]. The orange lines indicate the intensity of V-HARP1, the blue lines indicate the intensity of FM4-64 in leaves pretreated with DMSO (CK), BFA, A23 and Wm, respectively. e Detection of HARP1 in leaf discs by immunoblot assay. The wounded leaf discs were pretreated with DMSO (CK) and A23 before incubated independently with V-HARP1 solutions and the OS of cotton bollworm larvae. Anti-HARP1 antibody was used to detect V-HARP1 and HARP1. f Whole amount immunohistochemistry detection of HARP1 at the wounding sites. The OS-incubated leaf discs as described in (e) were used for assay. Anti-HARP1 antibody was used to detect HARP1. Scale bar: 100 µm. Source data are provided as a Source Data file.