Fig. 4.
VAN3 and GNOM involvement in endocytosis. (A–C) Reduced uptake of the endocytic tracer FM4-64 (5 min incubation) in van3-1 (B) and weak gnom (van7) (C) mutants compared with the wild-type Ler (A). (D–F) Inhibition of the internalization of PIN1-GFP in response to BFA (30 min, 50 μM CHX followed by 60 min of 50 μM CHX/40 μM BFA) in van3 (sfc-9) (E) and gnomR5 (F) mutant roots compared with the wild-type Col-0 (D). (G) Quantification of FM4-64 uptake in untreated van3 and van7 mutants. Quotients of the fluorescence signal intensity between the inside of the cells (excluding the PM) and the PMs were calculated and given in the ordinate. Note the inhibited uptake of FM4-64 in van3 and weak gnom (van7) root cells. (H and I) Inhibited internalization of FM4-64 in BFA-treated roots expressing the BFA-sensitive GNOM (GN-sens) (H) compared with the BFA-resistant GNOM (GN-Res) (I). The comparison was done in the background of gnl1 mutants expressing the BFA-sensitive GNL1. Seedlings were pretreated with 40 μM BFA for 30 min and were pulse labeled with FM4-64. Time points after the FM4-64 pulse are indicated. (Scale bars in A–I: 4 μm.)