Tissue analysis of stems in irx7 and irx8 transformant lines. (A1-G1) Immunodetection of xylan in transverse stem sections with the LM10 anti-xylan monoclonal antibody. (A2-G2) Lignin deposition in the secondary walls was stained with Phloroglucinol-HCl. (A3-G3) Same as A2-G2, at higher magnification; arrows point to some of the irregular xylem cells. Scale bars for all panels: 100 μm.