Fig. 1

Colonization of cucumber roots by weakly virulent strain WT marked with GFP. Laser scanning confocal microscopy analyses of cucumber roots 24 to 120 h after replanting 7-day-old germinated sterile seedlings in soil containing conidia of transformant gWT. a 24 h after inoculation (hai), several spores germinated and begin to penetrate into the plant cell. b 36 hai, a small hyphal fragment was observed in the root. c 48 hai, d 72 hai, hyphae extend along the epidermal and cortical tissue of roots. e a small hyphal network has formed in roots 96 hai. f 120 hai, hyphae developed in roots and form expanding networks in cucumber roots that exhibits rot symptoms. Arrows represent conidia in root tissue. Scale bars = 100 μm