Fig. 3

Putative mechanism of phytoplasma adhesion to and internalization in the epithelium of insect vector midgut (a, b) and salivary glands (c, d). Following infectious nutrition (a, b) or abdominal microinjection (c, d), phytoplasma cells reach the microvilli of the brush border membrane of vector midgut epithelium (a) or the salivary gland epithelium (c) of the vector, where native antigenic membrane protein (Amp) molecules within the phytoplasma cell membrane may specifically interact with putative vector receptors, and start vesicle-mediated colonization of host salivary glands (c). Masking of native Amp by its antibody A416 (b, d) impedes the interaction with putative vector receptors, therefore blocking midgut crossing and decreasing acquisition efficiency (b) or affecting salivary gland colonization and decreasing inoculation efficiency (d)