Fig. 1

Immunofluorescence detection of Rice black-streaked dwarf virus (RBSDV) P7-1 in the alimentary canal of viruliferous small brown planthoppers (SBPHs). The internal organs of SBPHs were immunostained with P7-1-FITC (green), P9-1-rhodamine (red) and actin dye phalloidin-Alexa Fluor 647 carboxylic acid (blue) and then examined under confocal microscopy. a At 2 days post-first access to diseased plants (padp), P7-1 and P9-1 antigens had accumulated in midgut epithelial cells. Panel I is an enlarged image of the boxed area in panel a, showing P7-1 and P9-1 in epithelial cells. b By 3 days padp, P7-1 had formed into tubules in the midgut epithelial cells. Panels II, III and IV show enlarged images of the boxed areas II, III and IV in panels b(i) and b(ii), demonstrating the range of morphologies of P7-1 in the epithelial cells. c At 6 days padp, P7-1 and P9-1 antigens had accumulated in the circular muscle and longitudinal muscle of the midgut, but did not yet appear in (d) the salivary glands. Panels V and VI show enlarged images of the boxed areas V and VI in panel c, demonstrating the spread of P7-1 in the visceral muscle of the midgut. By 10 days padp, P7-1 and P9-1 antigens had accumulated in (e) the whole digestive system and (f) salivary glands. mg, midgut; hg, hindgut; sg, salivary gland; me, midgut epithelium; lm, longitudinal muscle, cm, circular muscle; scale bars, 30 μm