Figure 5.

Fluorescence observation of Azospirillum brasilense 1224^T harboring the plasmid pBBR1MCS-2::mCherry inside the bulb (underground stem) tissues of the onion seedlings at 28 days post-inoculation. The transverse bulb section (b) was prepared by slicing the bulb at a red line as shown in (a), and the cells localized in the section were observed using an inverted fluorescence and optical microscope. Boxes show the enlarged region of the insets. (a) Bulb (underground stem); (b) transverse bulb section; panels (c) and (d): Overlay of optical and fluorescence images. Scale bars: (a), 4 mm; (b), 500 µm; (c) and (d), 5 µm.