Laser-microdissection of epidermal cells from AM roots and of root areas containing appressoria. Collected areas are marked with blue dots framed in green. Arbuscules and appressoria are marked with yellow and blue arrows, respectively. Epidermal (EPI) samples (A-C) were collected from root areas containing mature mycorrhizal structures. The isolation of ARB and CMR cells from these samples has already been described in . For the harvest of appressorial (APP) areas (D-I), roots were subjected to a short ink staining and screened for early infection units prior to embedding (D). During laser-microdissection, epidermal regions where fungal hyphae were penetrating the root and the cortical cells beneath were harvested for APP areas (F, H). In cases where arbuscules had already developed in the inner cortical cells (E, F), those cells were not included. Scale bars represent 200 μm for D and 150 μm for all other panels.