Fig. 6.

Accumulation of flg22 in plant cells requires FLS2 and endocytosis. Arabidopsis leaf discs were floated on TAMRA–flg22 (Tf22) with and without an endocytosis inhibitor for 1–2 h (A, B; 5 μM TAMRA–flg22) or overnight (C, D; 1–2 μM TAMRA–flg22) and washed in water. Fifty micromolar MG132 or 50 mM BDM was added simultaneously with TAMRA–flg22. Fluorescence was quantified in confocal microscopy images such as in (A, C); data were combined from at least two experiments for each genotype/treatment and shown as percentage of TAMRA–flg22 signal in Col. Letters indicate significant difference (ANOVA/Tukey’s test). Background fluorescence in the absence of TAMRA–flg22 was negligible. Bar: 10 μm in (A) and 20 μm in (C). (A, B) Initial (up to 1.5 h) uptake/binding of TAMRA–flg22 is reduced in fls2, but not highly affected in bak1 or in Col treated with inhibitors. P<0.05, n≥6. (C, D) Overnight accumulation of TAMRA–flg22 in plant cells is inhibited in fls2 and bak1 and in Col treated with inhibitors. P<0.0002, n≥7.