Tension wood delay in programmed-cell-death. A Top, single representative images from the stack reconstructed from the X-ray CT scanning of each RW induced stem segment. Bottom, Transverse middle stem section (25 μm) of a RW induced tree stained with safranin O (red – non-specific staining the cell wall) and chlorazol black (black – specifically staining the g-layer of g-fibres). Scale bar = 4 mm. B Confocal micrograph of coomassie stained OW (top) and TW (bottom), autofluorescence is shown in red (excitation and emission wavelengths were 488nm and 500-700nm respectively). Panes highlight the difference between OW fibre and TW g-fibre development in terms of individual cell structure and greater tissue architecture in relation to the whole stem. Blue scale bar = 500 μm.