Fig. 1
From: A protein complex required for polar growth of rhizobial infection threads
VPY is required for rhizobial infection in the epidermal and nodule cells. a–b Confocal images of vapyrin-1 (vpy-1) mutant showing normal root hair curling and entrapment of rhizobia. Upper, merged image of bright field and GFP; lower, merged pictures of cell wall auto-fluorescence and GFP. c–h Root hair infection phenotypes of vpy-1 (c–e) and control plants (sunn-2) (f–h) at 2, 3 and 4 days post-inoculation (dpi) with Sm2011-GFP, showing exaggerated radial development of the infection chamber and abnormal nucleus positioning in the mutant. White arrows indicate nucleus in c, d and f. Blue arrowheads indicate the cytoplasmic bridge in vpy-1 (inset in c). White arrowheads indicate rhizobia in the infection chamber (green). Red arrowheads indicate elongated infection threads in control plants (g, h). Insets in c, d correspond to the same root hair at a lower magnification, showing the positions of nucleus. n, nucleus in a. White dashed line indicates the contour of the nucleus in f. i, j Longitudinal nodule sections of X-gal stained WT (i) and vpy-2 (j) nodules. k Toluidine blue-stained longitudinal nodule section of vpy-2. Nodules were collected at 47 dpi. Blue colour i, j indicates X-gal staining of Rm1021-lacZ. Red arrows indicate abnormal intercellular accumulation of bacteria (j, k). l–n Transmission electron microscopy of nodule cells from WT (l), vpy-1 (m) and vpy-2 (n) at 47 dpi showing intercellular rhizobial infection. Red asterisks indicate rhizobia. Arrowheads indicate plant cell wall. Arrows indicate unidentified electron dense material accumulating in the intercellular space occupied by rhizobia (l–n). Scale bars, 10 μm (a–h), 100 µm (i–k) and 1 μm (l–n)
