Fig. 5

Light micrographs of radial sections, stained with toluidine blue, showing vacuoles in ray parenchyma cells a in the current year’s xylem (the differentiating xylem), b in the middle part of the sixth annual ring from the cambium (the middle part of sapwood), c in the middle part of the tenth annual ring from the cambium (the middle part of the intermediate wood), d, e in the middle part of the eleventh annual ring from the cambium (the inner part of the intermediate wood), f in the middle part of the twelfth annual ring from the cambium (the middle region of the outermost part of the heartwood) and g in the inner part of the twelfth annual ring from the cambium (the inner region of the outermost part of the heartwood). Light micrograph (e) shows the inner part of the lower ray parenchyma cell in d (as indicated by an asterisk in d). White arrows indicate nuclei. Black arrowheads indicate protein storage vacuoles (PSVs) and non-PSVs. White arrowheads indicate deformed vacuoles. A black arrow indicates a large vacuole in the inner intermediate wood. Yellow arrowheads indicate osmiophilic aggregates and yellow arrows indicate lipid-like oily droplets in the heartwood. Bars 40 μm