Fig. 1

The positively charged domains of GPT1/2 bind MTs in onion epidermal cells. Full-length and truncated fragments of GPT1/2 were fused to GFP at their C-termini, and transiently expressed in onion epidermal cells. a and d Charge plots of GPT1 (a) and GPT2 (d). b and e Protein structures of GPT1 (b) and GPT2 (e). The positions of basic amino acid residues are indicated by blue lines. The N-terminal (N) regions are negatively charged, whereas the middle (M) and C-terminal (C) regions are positively charged. c and f Localization of GFP-fused GPT fragments to cortical MTs is indicated by ++ (strong localization), + (substantial localization), +/- (weak localization), and – (no localization). The numerator and denominator show the number of cells with positive localization patterns and the number of total cells that expressed GFP fusion proteins, respectively. The GPT2-GFP fusion (f) was co-expressed with tagRFP-MAP4 to visualize MTs. Left panels, GPT2-GFP; middle panels, tagRFP-MAP4; right panels, merged images. Scale bars, 10 μm