MtEPP1 plays a limited role in the AM fungi symbiosis. (A) Percentage of root length colonization that includes arbuscules, hyphopodia and spores, and (B) percentage of arbuscules in MtEPP1-silenced or control vector transgenic roots. Data shown were obtained from four independent biological replicates, each one containing 10 transgenic roots. An asterisk indicates a significant difference according to Fisher’s exact test (P-value <0.05). Arbuscules (a) and hyphopodia (h) which developed in control vector transgenic roots (C and D) were similar to those formed in MtEPP1-silenced roots (E and F). The scale bar represents 10 μm in (C) and (E), and 2 μm in (D) and (F) Pictures shown are representative of four biological replicates, each one containing 10 transgenic roots.