Immunogold labelling of phloem cells with TLP1 antiserum. A) Low magnification image of a phloem parenchyma cell (scale bar = 5 μm). B) High magnification image of starch-containing plastid showing TLP1 immunogold label (scale bar = 500 nm. C) Low magnification image of phloem fibre cells (scale bar = 2 μm). D) High magnification image of pectin-rich cell corner showing TLP1 label (scale bar = 500 nm). Arrows indicates positions of areas enlarged in panels B and D. PP, phloem parenchyma cell; S, starch; PR, pectin-rich region; PF, phloem fibre; SCW, secondary cell wall.